RC India

Hello everyone,
So i finally got a mini titan pro from a friend of mine.  The ARF includes the heli + 4 servos and gyro.
The servos are already installed and it seems that there is not much to do before i can start flying ( and learning ).

Since this is the first time i am going to build and fly a heli , in fact the first time i have seen a RC heli so closely, and i am amazed at the complexity and how many parts are there in this. I am glad i chose an ARF rather than a kit, otherwise i would have surely messed up.

The next steps i see are :
Install the tail boom
Install blade grips and main rotor blades
Install receiver
Install Decals and canopy,
Go fly !

As i thought i would be needing help from Anwar and everyone here who has experience with helis.
The first question i seem to be having is that the battery has bullet-type connectors. Now though i have a charger, i am not sure how to connect these. Are these connectors available locally ? I would appreciate some advice, so i can charge the battery !

Thanks
Gaurav

Rajesh/Rotorzone is our best resource when it comes to Mini Titans.

I would be surprised if the battery did not have a balance connector.  Depending on the charger, you can charge through the balance connector alone (you have to do slow charging, like at 0.8A or something like that, as the wires of the balance connector are thin, and this method is discouraged by some), *OR* you can use the bullets to do the main charge at full 1C rate and use the balance connector for balancing alone (but you will have to solder up a corresponding bullet connector whose other end is compatible with your charger connectors).

Bullet connectors are available at RCDhamaka :

http://www.rcdhamaka.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=bullet

but make sure you get the right size.

The first question is, what charger do you have ?

I have the Tahmazo Charger. It supports Lipos and has a balancing port. I needed the bullet connectors so i could solder them to a Deans, which the charger supports.
I will search the local market today to see if i can find these here.

I am very excited !!!
I attached the tail boom, and the main blades, and then connected the Rx, battery and wow this thing worked !!!
I had to get out the manual in order to get past the ESC's tone-alerts and setup , but once set i got the servos to operate and the main rotor to whirrr !!!

There are a bunch of things to still finish, and i "just" hope to learn to fly this !

Why have multiple connectors? Just remove the bullets and replace them with Deans. Observe polarity!!

Guess he is going to use the new "bullets on one end and deans on the other end" only for charging only, and use the existing bullets on the battery and the ESC for flying  :headscratch:

Right ! I am trying to find the bullets and will solder them to a Deans using some wire, and use that for charging...
I do seem to require a smaller screwdriver set, as some of the screws are so small ! Will get one jeweller's screwdriver set today

Sushil bhai's point is that you don't have to wait if you just replace the bullets on the ESC and the battery with deans, if you have them in stock. This would be a better solution long term also, as more and more 3s lipos are now coming with deans females pre-soldered.

The excitement continues  !
So i had the main rotor blades in place, soldered a connector to the batter th at was compatible with my charger and charged the batter at 1C (2.2A) with the balancer connected.
Everything looked good, and i was dieing to see the heli in action. So I took it out in my garden, and very slowly increased power. I must say that ther sound of the blades was sweet. So now i was around 40% power and the heli seemed light on skids. i wanted to ensure the trim was set up OK. So i gave a little bit more power and noted that the heli wanted to bank to right with its nose down. SO i reduced power and gave 3-4 clicks left and up on the trim. Till tis point i did not have the heli leave the ground.

Then i tried again, and there it was ! just took off straight up and i hovered it at 1 feet for around am minute. I must say it was sensitive and felt JUST like the sim. This was so exciting !!

I need to practise a lot to get used to the sensitivity, and overcome the enxiety. I did do 2-3 hoverings again , though just at about 2-3 feet.

I had not put up the training gear, so in of my hoverings, i had the main blade touch the ground ( ouch ! ) and the the tail rotor too :(( However nothing broke, though there are small nicks on the blades. I want to continue with them and change later. Would that be ok ?

I have the battery on charge, and will try again in the afternoon wit hthe training gear on.

Good thing is that my lawn is perfect for helis, and now i can get into RC without going to the field and getting all the airforce attention !!

-Gaurav

Two points to note :

1.  Real life is never like the sim ;)  Depending on a lot of factors, these CP helis does NOT lift up perfectly and come down perfectly with throttle. I have had a hard time with some flyers when I do setup for them, where they insist that it does not hover like in the sim  :banghead:

2.  Hover above couple of feet.  The "ground effects" can induce instability.

About the cuts and nicks on the blades, if you do not feel significant vibrations (which started after the blades were hit), you are probably OK for now.

BTW, post some pictures of your wiring etc.  Also, how did you setup the gyro (what gain etc) ?

Ok, I am aching to go back home for lunch and try this again. I guess it was beginner's luck for me, as i had to do no setup at all ! ie i went with the factory settings on the gyro, esc etc .. I do plan to read and understand the manual, but as of now i think i need to practise :)

Good going. If you have damaged the shrink wrap on the blades, it will cause lot of flutter and might even rip off. Since a major part of the blade is holed out for lightening, this could be disastrous. If you have to, use tape to fix and balance both blades.

thats some really valuable advice.. thanks !!
Would you be having CF blades for this ? or should i order from HK

I wanted to give an update on whats happening here.
I have been able to do some hoverings, and like the heli. I do feel that it will take some practice before i can move on to other stuff .
I did also had a minor crash and broke the main blades, which in any case were extremely flimsy. Also i noted that the gears on one of the servos were stripped, so currently waiting on the spares to arrive.

I did want to buy the Carbon fiber blades form hobby city, and liked this one : http://hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8395&Product_Name=325mm_Carbon_Fiber_Main_Blade_Yellow_(1pair)

However someone has commented that i would need the CFB holder too . Does that mean that i would need something else before i could use these blades on my heli ?

I plan to order the CF main rotor blades and the tail blades from Hobby city

Thanks
Gaurav

They must be talking about these, which are plastic spacers that have to be bent and placed in the blade holder, to compensate for the difference in thickness of the blades where they are attached to the blade holders.

http://www.amainhobbies.com/product_info.php/cPath/2_375_569/products_id/16223/n/Thunder-Tiger-Rotor-Spacer-E325 (shows unbent state).

http://www.radiomodellers.com/pv0829thundertigerminititane325rotorspacer-p-74.html (shows bent shape).

BTW, we always used to say that CF blades are a waste of money when you are starting out.  But at these prices, it has become sort of just a matter of personal preference now. 

Thanks Anwar.
What are the disadvantages with the CF blades over wooden.  Cost wise they are the same to me, and i believe CF would be a better choice ? I am not after performance or optimizing battery time etc. My main aim is to be able to learn to fly helis at this stage, while keeping the costs down as much as possible.

CF blades are higher performance.  They usually come better balanced, are sturdier and many people notice lesser amps drawn while using them.

But as a beginner who is prone to crashes, the wooden blades may be slightly better, as they take the impact when crashes happen, and save other parts of the head from breaking.  Of course, what all ends up broken depends on the nature of the crash etc, but it is good to let the first guy take the bulk of the impact, and the woodies do better in that aspect. 

One thing is for sure.  When you start doing aggressive flying, it is better to use the CF ones.

Just got my package from Rotor containing 3 nos Hitec 65MG servos. Cannot wait to put them in my heli.
I will be replacing all 3 servos with these metal gear ones. The Ace C1016 servos which were there originally, stripped way too easily with a tip-over.

Now over the last week i read through the manual, and inspected the heli closely to understand the part names, and what-goes-where. I did also find a small issue with the motor pinion not set at the correct length hence not using the entire main gear's width , which i fixed.

Will install these new servos today and hopefully will be flying tomorrow !

-Gaurav

Well I have had some mixed experiences over the weekend.
First i replaced the C1016 servos with the Hitech 65MG ones. The mounting holes did not match and i filled the existing holes with epoxy and then drilled the new mounting holes. Changing the servos was a big excercise, as i had to remove the main rotor assemble in order to drill/mount the servos.
Then the linkages needed to be adjusts to match the new servos. I went by the manual, and had the swashplate level.
Went out in my garden and hovered !! loved it ! . Though i ferlt that a bigger space would have given me more safety.
On Sunday took it to the flying field and hovered it with the tail towards me, for the entire battery pack. I did notice a couple of things and perhaps the Heli-experts here could comment on it :
1. When i rev-up the motor and the heli leavs the ground, the tail swings. I use the rudder to get it back in place, but is this something that always happens , or is it somethign wrong with my setup.

2. Perhaps it was the wind, but somehow i felt that when hovering my heli was slightly tilted to the left Not that it was going in the left, but i just 'felt' it was not perfectly level. Again is this something wrong with my setup ?

3. To check the swashplate i just viewed it from the back and side, but i guess that isnt a very accurate method. How do you use the bubble-level to measure this ?

4. I have the Thunder Tiger Pitch gauge, but it seems big for the mini titan blades. Any way i can use this ? or do i need to shell more $$ and buy a smaller one.

Ok So i am all happy and excited with my heli, took it out today again, and though flying well at the end i brought it down faster than planned and had a tail strike ( ouch ) ! Well the tail boom, main blades, tail-blades, and the mixing lever got damaged. Well time to order !!!
The lesson i learnt was that i need to spend more time practising with the Simulator.

Look forward to your comments.
-Gaurav

Are you taking off too soon before the head RPM builds up ? If so it is normal, just wait for the RPM to build up. If the tail swings when on pitch pumping, you need higher gain on the gyro.

Doesn't make sense, it should be tilted to right unless you are hovering inverted ;)

Measure the pitch on one blade at every 90deg rotation. If it is not same, your swash is not level.

The big gauges are too heavy and twists the blade/head a bit to get proper readings.

Oops Yes its tilted to the right !!! Sorry about that ! Is that normal ?

Looks like you have been bitten by the heli bug  :thumbsup:

Furthermore, hopefully you do realize that such crashes are part of the deal, and do not get discouraged now itself (I have seen so many of those :( )

I have been using an Align pitch guage, which works well for all sizes (300mm to 700mm blades) :

http://www.heliproz.com/prodinfo.asp?number=335471

Were you flying with training skids ?

Yes indeed. I am starting to like Helis and the main reason is that they promise me ore regular/frequent RC activity than airplanes. Although i have had 2 crashes in my not so long heli career, i am not discouraged yet. Thanks to this forum, especially Anwar and Rajesh, and thanks to the LHS it is now possible for someone like me to enter Helis and not worry about parts availability.

Yes i was flying with training skids, and though they help me, i need to be very patient and slowly progress. I tried to hurry up things today that led me to this crash. I guess i will 'just' practise tail hovering for at least 20 flight before moving to anything else.

So my question went unanswered. Why is the heli slightly tilted to the right even when hovering ?

Rather than me trying to explain and messing it up, here it is :

http://www.iheartheli.com/index.php?option=com_content&task=blogcategory&id=16&Itemid=38 (see the question "Why does the helicopter want to slide to the left? Why does it lean to the right when in a perfect hover?")

Think of it as something similar to why you need the 3degrees right+down thrust in airplane engine mounts.  Not exact, but similar in that it is an effect of the rotating and counter rotating forces generated.

Thanks,
Quick question : I have a Futaba 10C . Now the Mini Titan came with a Gyro that has ECCPM mixing built in, and that is what i have been using so far. Is it better to continue using this, or should I setup my TX to Heli mode and use that ?

Short answer... it will give you more setup options. Rajesh has more hands-on experience on the Mini-Titan, so it would be interesting to hear his opinion on this.

My experience is also limited as I don't fly a mini titan. My preference is to set up on the radio and use the 6100 just as a gyro. It doesn't matter to you at this stage. In later stages, when you feel the need to tweak the curves according to your needs, radio setup will be the way to go. I don't recall now, but I believe you cannot setup a throttle hold with 6100.

"Throttle hold" is another key component / setup in heli flying. Enabling it and using it at the right times can save the flyer his heli, and is an important aspect of safety when it comes to heli flying.

And what exactly is throttle hold ?

Throttle hold, in simple terms, is like disconnecting the main blades from the motor. Think of it as putting a car in "neutral" gear, or pushing down the "clutch pedal" of a car all the way in. 

In electric helis, this is done by shutting down the motor (regardless of the throttle stick position). In nitro helis, this translates to taking the engine to idle rpm, where the clutch disengages and the slow rotation of the engine is NOT transferred to the main blades.

Once you put a heli on "throttle hold" (after you have correctly enabled that in the radio), you can move the throttle stick up without having the main blades spinning up, thus allowing you to check the pitch of the main blades (without having to disconnect the motor, in the case of electrics).  Needless to say, if you put the heli on hold after you connect the battery (or start the nitro engine) until the time you actually start flying, the risk of the heli doing something bad if you inadvertantly hit one of the other controls (including throttle) are greatly minimized.  We tend to follow this as a best practice on our field.

More importantly, throttle hold allows you to do auto-rotations. For example, if the tail belt of your heli broke and you lost tail authority, then hitting hold will allow you to control the pitch and land the heli safety, without worrying about the motor driving the main blades at any throttle/pitch position (assuming your heli has a one-way bearing on the main gears that allows such a feature).

Finally, if you lost your orientation and are about to crash, hitting "hold" before impact greatly reduces the amount of damage your heli will sustain.  The crash is much more severe if the heli hit the ground while the motor/engine is still driving the main blades.

Wonderful explanation. Thanks !
I guess i will use my TX's programming over the ECCPM mixer, as this will give me access to these features.

Got a question.
As you know i have been flying around the mini Titan. Now i havent yet really put the canopy on. But i figure it would be best if i do this ( will protect the motor from dust etc ) .
Now i am concerned as to how would i charge the battery without removing the canopy everytime. Is that possible > Taking the canopy e very time is an added task i would like to avoid, but not sure if there is any way out.

Another question. Should i use a switch between the battery and ESC ? Currently i just plug in the wires, not sure if this is the standard practice.

Thanks

Removing canopy is the standard practive for electric helis. Most people will have more than one battery so they don't need to wait an hour for charging between every flight. So no other way around.

Do not use a switch. The current is too high to use a reasonably sized switch. Addition of even mOhm resistance of the switch in the path is going to reduce the power available.

Thanks Rajesh,

Now that i connected my servos directly to the RX, thereby using my 10C's mixing functions, i have a question.
So far i have the reversing properly setup so the swashplate descends when I increase the collective, and tilts in whichever direction i give the cyclic.

Now I am trying to get a pitch reading of 0deg at mid-collective. The servo arms are perpendicular at mid-collective, but i am having a hard time getting the pitcha gauge to read 0 degrees in all 4 directions..If i change thethrottle linkage height at the rear to get a pitch reading of 0 degrees, the settings in the front change, and if i touch the front two , the setting at the back changes.

Any idea on what i may be doing wrong ?
BTW to check the pitch i have placed a bubble-level on the flybar, and one on the pitch gauge. i chechk the pitch with both these at level...

Don't think you are doing anything wrong. By adjusting the lengths you can get close, you'll need to use subtrim to get the final adjustments.

BTW, do not kill yourself on swash leveling. Regardless of your efforts there, you may still need slight trim (which means that you move the swash out of its level position) to handle CG issues or when beginners prefer to have the heli always have a little forward elevator (so that the default action is for it to move away from you).

Just do the best you can (without spending an inordinate amount of time on this part), and do the rest of the trimming while on an actual hover.

Thanks Anwar and Rajesh.

One more thing, the manual suggest the following pitch curve for beginner :
1    2   3    4    5
40  -   75   -    100
-2        +5        +10
And for throttle :
1    2    3    4    5
0    45  65   85  100

Is this a good / recommended setup ? I see this as a 5 point curve, what values would i need to feed in for a 7 point curve on 10C ?

Thanks again. I want to fly this tomorrow but want to double check everything.
-Gaurav

Those are pretty good values to start with.  It sort of ensures that you can hover around middle position on throttle.

About the pitch, go by the degrees only (-2, +5, +10) that you measure from the blades and NOT the by the actual values you set in the radio (40-75-100).  This is because of the fact that those numbers assume that you have a perfect setup (0-50-100 on the radio translates to -10,0,+10 on the blades), but in practice you are a little bit off most of the time.

one quick one on the curve. Why do we need the slight negative on 0 throttle position ? I mean since I do not plan on inverted flying ... What that does is when I lower the throttle the helicopter comes down very fast almost slams down... If I had 0 pitch at idle perhaps this wouldn't happen ?

Because the heli would refuse to come down if it is windy  :P  I typically ask other beginners who have a separate curve for normal to use -3 or -4. 

Yet another reason is for it to aid with auto-rotation (especially for fuel powered ones), although many have a separate curve for throttle hold.  Having negative in normal mode helps if you forget to hit throttle hold before doing an unplanned auto.

Thanks Anwar,
I didnt understand the Autorotation part but i guess I am still far away from that.
Now i couldnt resist going out in my driveway to test the heli . here is a video :

http://www.youtube.com/watch?v=6F_bFo_DRmw

Now the major things i did in the last week was :
1 - Replaced bent shaft, tail boom and a blade grip from a crash last week.
2 - Now using my 10C programming . Used the recommended throttle/pitch curve, as posted earlier.

Now there were a few things i found different from my earlier experience :
1. The heli seems to be bobbing around in the hover. There was some wind today, due you think thats the cause of it  ?
2. The tail boom got slightly warm after the flying, i had installed the belt with care, so do you think i need to open it up to check ?
3. The sound of the motor/gear was a little different, maybe since i replaced the shaft, the gear position changed and it needs to re-mate ?
4. The motor was quite warm after a 7 minute hovering practise. is that normal ?

Thanks again, I owe my heli flying to this forum, without which i wouldnt have got into Helis.
Gaurav

Oh man, I am jealous of you now. ;D Iam still struck with my build.

One major possibility that can cause this type of wobbling is not enough head speed, so try increasing your throttle curve.  The wobbling is not consistent with wind effects. Also, double check your belt and its tension.

The gears should overlap each other as much as possible. To get the right tension between your motor pinion to the main gear, take a small piece of paper, and fold it in half, so that you have double the thickness of a standard notebook sheet of paper. Now place that piece of folded paper between the main gear and the motor pinion, and close the gap between them as much as you can and tighten the motor firmly in its place.  The paper will get crushed into a zig-zag pattern between the two sets of gears.  Now rotate the main gear manually so that the paper bit falls out. This leave the right gap (or lack of gap) between the main gear and the motor pinion.  This also makes sure there is no undue forces on the motor shaft, which can cause early bearing failures (and possibly heat issues). 

Motors to tend to get hot during flight. But they should not be too hot that you cannot even touch it.

And congrats on your heli flights !  Looks like the training skids are really helping you, you would have sustained some damage without them already with this type of test flying. Please fly in a larger area, and keep the heli at a bit more distance from you.

Thanks Anwar,
Increased headspeed helped. The 10C has two dials VR(A) and VR(C) to independently tweak the pitch/throttle curves at hover . I used them to correct the bobbing, and will go program them in the curves.
Now the next issue i seem to have is that when the heli is light on the skids, ie just below the hover point it wants to go to the left side, but when its in a hover, it is balanced. Looks like i need to tweak the end points of the 2 forward servos. What do you suggest, should i decrease the end point of the left servo ?

Yes the training skids do help me, and i plan to go a park near my house to fly . Sometimes i cannot resist flying at home, but i try to be very very careful.
I will post some picture here soon,
-Gaurav

The Vr(A) and Vr(c) things are a boon and a bane at the same time :(  I ask people to disable them, and do any tweaks on the pitch and throttle curves directly so that they are permanent, and safe from unintended changes (it is easy for people to rotate those knobs my mistake while handling the radio).  It can also cause funny issues like the curves being not straight lines even though you have set the intermediate points linearly.

My experience is to NOT try any trimming unless you are at least a couple of feet above the ground.  The "ground effects" are significant, and they tend to mislead you.  And even if the heli shows a tendency to drift, the right thing is to adjust the trim/sub-trim (not end-points). If there is wind, point the nose of the heli into the wind while you are trying to trim it.

Hope to see more of your progress, from a bigger field ;)

Hmm. Looks like i am addicted to Helis now.
I tweaked the subtrim/trim and did not touch the EPA and i think i resolved the problems i was encountering earlier today. I flew 3 battery packs today ( i have a 2200mah one on this heli ) so each flight lasted for around 8-10 minutes.
Now i have a few more questions :
- At what point should the servo arms be straight - ie 90 degrees to the servo. Should it be at 0 pitch ? or hover ?
- Ever since i switched to 10C programming, i noticed that the heli wants turn to its left, ie i need to give very slight right rudder. Do i need to increase the gyro gain ? I checked to ensure that the "revo" mix is INH on the radio.
- Should Lipo batteries be allowed to fully cool down before recharging ? ( i have just one pack and cannot wait to take the heli into a hover again.

Well i have not yet gone to a bigger field yet, and still practicing hovering at home. I know its like calling for trouble, but i am extra careful, and my next video today will hope fully show that i can keep the heli at same place now for the entire hover.

During my initial hovering attempts, to bring the heli down, i used to bring the throttle lever completely down , perhaps out of practise from airplane flying, where reducing the throttle did not create an "instant" effect like on helis, so what that caused was that the heli used to literally drop to the ground, so i have now improved upon it.

I will stick to hovering the heli in the same place with the tail towards me for the next 10 flights or so ( you think this should be good enough ? )  Then perhaps try to practice side hovers , before moving to nose-ins ? My goal is to first master hoverings from all angles before moving to forward flight..

Will post videos / pictures today.
-Gaurav

Many many questions :)  That is a good sign  :thumbsup:

For the swash servos, you want the servo arms to be at 90 degrees when you are at mid-stick. At this point, if you have done everything right, the swash should be almost at exactly the middle point of its maximum range of travel (both up and down from the middle point), the swash should be level and the pitch on the blades should be zero.  Note that it not at hover, it is at mid-stick on the throttle.

For the tail servo, it should be 90 degrees in rate mode, with no rudder input and no rudder trim (I also avoid any sub-trim on rudder)..

Like I said before, you are better off putting the gyro in rate mode, and adjust the mechanical setup first (ensure there is no trim at all on rudder). You should do that at a rate mode gain of around 50.  Now switch to heading hold, and if you are still seeing a drift, that could be due to low gain, or your connections being wrong in that the gain set in the radio is not being communicated to the gyro properly.

Let the lipos cool down, it helps with their life is what I have found from other sources.

Stick to hover for a few more flights, and then try side hovers.  I would suggest forward flying (circuits) before trying nose in.

Thanks Anwar ( I guess thats going to be my first line of every post ) :)
I got the heli on the bench and tried to get the arms to be 90 degrees at 0 pitch with the TX throttle stick at middle ( and the pitch curve rest so that the mid throttle says 0 . Now i am a little confused with the Pitch curve numbers . In the mini Titan manual it seems to assume that 50 is 0 deg pitch. thus 40 is referred to as -2 pitch.
However on 10C, there is a range of +100 and -100 , so in that case 0 , or the midline in the graph should be the 0 pitch ?
Do you think that i am doing this correctly ?

Now, regarding the gyro. , you said "if you are still seeing a drift, that could be due to low gain, or your connections being wrong in that the gain set in the radio is not being communicated to the gyro properly."

Where is the gain set in the radio ? or does it need to be ? Should i try a hover with the Gyro in the rate mode ?
I did setup the servo linkage so that in rate mode, with the tail blades's pitch to 0 the servo arm is 90 degrees.

So far i have been flying in the Heading hold mode only ...

Get out of the habit of looking at the numbers in the radio when you set the curves.  Go by stick position alone. So whatever your radio shows when you are at mid-stick, that is when you adjust the links and servo-arms for zero pitch. In your swash menu (you should have one on the Futaba 10C), make sure your numbers are 50,50,50 (can be positive or negative depending on how you have wired up your servos.

If you have wired the remote gain settings wire to the gyro channel (typically channel 5 on Futaba), then you can use the "Gyro" menu to remotely adjust the gain.

Like I said before, you can continue to fly in heading hold, and your "less than perfect" settings will be handled by the gyro.  Keeping the slider right in the middle and using heading hold is the easy way out.

Note that in a perfect setting in rate mode, you will have slight pitch on the blades (to compensate for the main blade induced rotational torque), so this "put it in the middle" quick-fix is NOT the perfect setup *for rate mode*. It only gives you a good starting point for heading hold.

The right thing is to try to hover in "rate" mode, and length/shorten the tail servo linkage rod (or move the tail servo on the tail boom) to ensure that you have no drift in rate mode (with a gain of around 50).  This ensured your mechanical setup is almost perfect. After that you can switch back to heading-hold and keep it there; as you now have a solid tail.

One thing that ha e confused through this entire thread is, you say that when the throttle is at id stick position, the pitch should be 0 AND the servo arms perpendicular.
Also, I understand that i should be hovering at mid-stick position. SO how is this possible, i mean how will I hover with a 0 pitch at mid throttle ?
The pitch curve given in the manual says :
1    2   3    4    5
40  -   75   -    100
-2        +5        +10
That means that there should be a +5 pitch at mid stick, is that kind of pitch needed for hovering, and should the arms then be perpendicular at mid-stick with a +5 pitch ?

Please help !

Regarding the gyro, the TG-6100 Gyro I have has a CH5 connection that just switches the gyro between Heading lock and normal modes, using the CH5 switch on TX.
Now, from what i understand , you say that for a perfect setup ( which is what i am aiming for ) , i should switch the Gyro to normal mode, and have it hover in such a way that the servo arm is perpendicular during a hover ?

Anwar is talking about the case where he uses same symmetrical pitch curve for all flight modes. In that case, mid throttle stick is not the hovering position. It'll be a little above mid throttle.

For the gyro question, answer is yes.

Please see my response to Vinay :  http://www.rcindia.org/helis/hk-450-mt-build-thread/msg12654/#msg12654

Basically, when you do the physical setup, you always go for -10,0,+10 (with a linear pitch curve in the radio at -100,0,+100 or 0,50,100 depending on the radio). So at mid-stick, you will have zero pitch. 

After the physical setup is confirmed AND if you decide to have separate pitch curves for various flight modes, you adjust the pitch curve *for normal flight mode* so that you are -3,+5, +10 on the blades (which will translate to something like -30, +50, +100 on your radio). 

Or, you can follow what I have been doing, which is a single pitch curve for all modes, so that you will hover around 65% of the throttle stick position.  In this case, you adjust the throttle curve so that you do not have too much head speed around mid stick. But you will leave the pitch curve at -100,0,+100.

Regarding the gyro; for a solid setup, you should put it in rate mode with enough gain, adjust your mechanical setup so that the servo arm is perpendicular, but the pitch slider on the tail has a small amount of pitch (so it will not be in the center).  How much is that offset, is determined by flying the heli in rate mode, and adjusting either the length of the tail linkage rod, or by moving the whole tail servo on the boom (keeping in mind that the you want the servo arm as close to 90 as possible when you are not applying any rudder input).

Thanks Anwar/Rajesh,
That helped !

I am going to try and fine tune the gyro/rudder servo linkage today. Tell me something, suppose i have my heli hovering in rate mode, how will know if the rudder linkage needs to be increased/decreased ? In your last post you mentioned that there will be some drift. Wouldnt the drifting be compensated by cyclic trim ?
Perhaps i should have someone observer the heli from the side to see if the arm is perpendicular or not, and then land the heli and adjust and try again ?

In rate mode, when you have drift, you will be applying some rudder input to correct the drift. Note which side you are applying the input (let us say you were moving the stick to the left).  After landing, apply the stick to the same position, and see which way the linkage rod moved.  That should tell you if you should lengthen it or shorten it.

Or you can just do trial and error, and if you did it wrong, you will realize it while test hovering as you will have to apply more and more rudder.  If you see that is the case, do the opposite adjustment.

The drift we are talking about is tail drift, and has nothing to do with "cyclic trim", which is only elevator and aileron.  Tail drift is when the heli tends to pirouette by itself, and you are forced to apply some rudder input to keep the tail pointed towards you in hover.

The "servo arm" being perpendicular is something you can see on the ground, after the heli is powered up with the gyro in rate mode with NO rudder input.  Remember that we are not talking about the "tail pitch slider" being perpendicular.  You need to be clear about the difference between the two.

Anwar,
I have some results and more questions. I tried to do what you said above a few minutes ago .
First I switched my Gyro to Normal mode, and took the heli to a hover. I noticed that the heli wanted to turn left. and i needed right rudder to keep it straight.
So i powered down, and adjusted the servo linkage/position ( finetuned with subtrim )  so that in Normal mode, the heli was pointed straight in a hover with no need of rudder. At this position the servo arm was perpendicular to servo, BUT the tail blades were considerably pitched to the right.

So then i switched the heli back to Heading hold mode, but now it wanted to spiral to the right !! The Gain is set to 50 ( recommended in the Gyro manual )


The Gyro works fine, because yesterday only i flew in HH mode with the nose locked in .

One more observation. Suppose i put the heli on table and switch to Normal mode, The servo at this point is centered.
Now if i switch to heading hold mode ( motor and everything is OFF, and i do not even touch the heli ) , i notice that the servo  gradually tries to change the pitch of the blades to the right, till it reaches the end ..
Possible that i did something that damaged the gyro/servo ?

Please remove the sub-trim when you do the adjustment in rate mode.

It is normal for the servo to have some creep in heading hold mode, but not going all the way to one side (from what I can remember/imagine).  I think this is also an effect of the subtrim you have.  Please get rid of all trim and subtrim on rudder (channel 4), do the mechanical setup in rate mode again, and you should not have any problems. It is OK if the servo arm is not exactly perpendicular, so avoid sub-trim. Just do the best you can.

Please report what you see after trying the above setup.

Thanks Anwar.
I will try this first thing tomorrow morning. SO i will get rid of all trim/subtrim on rudder, then go back to normal mode on gyro and get the fly to track straight with no rudder input and servo arm at 90 deg.

Then will attempt to get on to the heading hold mode.

Is it normal to have the tail blade pitch almost at 75-80% travel in normal mode for the heli to track straight ?
Another question, that though i have tried to understand what the Gyro does, I am still a little fuzzy on what it does really in the normal mode.
In the HH mode it locks the heli to one heading, and counteracts the affect of wind/torque.
But what does the gyro do in normal mode ?

Best thing is that i am not crashing and getting to know the dynamics of heli better.

Oh one last thing.. Currently i have an odd ball mix of subtrims, and trims to have my heli hover without much cyclic . Is this OK ? Or should i attempt to get rid of trims by tweaking the linkages .
My objective is to have as close as a perfect setup as possible.

Thanks a ton !

It is NOT normal to have 75% travel to the side for the heli to hold its tail. You have to measure it *while you are actually hovering*, which is a tough task. It seems like the 75% is an exaggerated visual estimate.  It would be much smaller. If I were to guesstimate, something like 10% to 15% (again, I am pulling a number out of thin air, will try to confirm later).

Regarding the differences between rate and heading-hold modes, please see this : http://www.rcindia.org/servos-gyros-and-all-electronics/gyro-modes-normal-and-heading-hold/

My experience is that you will end up with some sub-trim on the swash servos (unless you get lucky by turning the servo arms OR you have a digital servo whose center can be adjusted with a "servo programmer"; some people I know do that on bigger helis, with Hitec servos).  Trim is something you can pretty much get rid of with careful setup.  At your present stage, I am not sure if it is worth the effort.

Ok i have some results and more issues/questions.
I reset the trim/subtrim on rudder channel to 0 . Then i got back to Normal mode and since i couldnt really get to the point for the heli to track straight on hover ( without any revo mix ) , i left it like that ( i read from the gyro links above that in normal mode the heli will slip a little to the left, unless revo mix is used to correct ) . The pitch at this point is slightly to the right, around 15% as you said.

Now i went to HH mode. the tail was good but then after about 10 seconds of hovering it started to move to the right. not a continuous turn but like a turn-stop-turn-stop...I had to give left rudder to get the tail pointed towards me. This was with 50 gain. I increased the gain to 75 and the tail wag came in , but even then the heli wanted to shift to the right.

Re trim/subtrim, though i want to have a perfect setup, i will not bother with it as of now, as the trims/subtrims i have are not too much, and plus i want to concentrate more on learning to fly now.

The battery is on charge right now. i will try to make a video and post it when i go home for lunch. I am a little worried that there may be a problem with the Gyro or the tail servo . Is that possible ?

Are you making your gyro changes from the radio (switching from heading hold to rate or adjusting the gain) ?  How are you confirming that the gyro has indeed switched from one mode to another ?

Yes I am making this change using the CH5 channel assigned to a 2-position switch on my TX. I have hooked up the CH5 on the RX with the Gyro, as indicated in the manual. Theres a LED on the Gyro, that turns red when in HH and Green when in normal mode , that is what i use to determine the mode.

The Gyro i have is Thunder Tiger 6100 gyro, and i believe it does not allow you to remotely set the gain using the TX. At least this was not said in the manual anywhere. Thus I assumed that CH% would not be used to adjust the gain, rather simply switch between HH and Normal modes.


Is it possible, that this CH5 may be the culprit ? Now that you have mentioned, I was not connecting this to the TX at all during my initial flights where i had the tracking better than what i experienced today

Just as I had suspected :)  The single green wire from the TG6100M is for remote gain adjustment, and it does provide the gyro with the gain value also (AFAIK).  So you should control the gain % from the GYRO menu of the radio, if you have that green wire connected to channel 5.

You da man !
Have you used the TG6100M Gyro ? Yes i have the green wirer connected to the Ch 5 .
Nowhere in the manual does it say ( unless i missed it somewhere ) that the Ch5 can be used to adjust the gain. It only says that it is used to switch between HH and normal modes.

Opens a can of questions. So now does the gain set from the TX and transmitted via the Ch5 override the physical gain set up ( using the small dial ) in the gyro  ?
Also, does the CH5 perform 2 tasks ? switch the Gyro mode +  adjust gain ?

Wow !

Yes, if you connect the remote gain wire then the gain is taken from whatever is supplied by the radio.

And it also switches between rate and heading hold based on the same signal. On most gyros, if, let us say the range of gain signal value is between 0 and 100, then 0 to 50 on the signal corresponds to 100 to 0 gain in RATE mode on the gyro AND 50 to 100 on the gain signal from the radio corresponds to 0 to 100 gain in HEADING HOLD on the gyro. JR/Spektrum radios work exactly like this. Futaba has this translation done slightly differently.

Hmm, That clarifies so many things. I will go home and see whats under the Gyro gain in TX and then perhaps set it up.
I will make a video of the entire setup and post here.
Thanks.

Ok, i read the Futaba TX manual and activated the Gyro Sense menu .
So now i can set the gain in the TX independently for Rate mode and HH mode. ALso using the 2-way switch i can switch between modes.
The gain setting on Tx for both rate and HH mode goes from 0 - 100 . However i am not sure how this translates to gain in the Gyro . Will 0 in TX be 0 in Gyro gain ? or will it be opposite ? Perhaps it works the right way in Rate mode and opposite in HH.

Well i flew with 50 as gain ( middle position ) and in HH mode. Even with no trim/sub trim, i had to touch the rudder to keep the tail locked in . I then tried to set the gyro gain to 0 in TX and flew . This time the heli wanted to yaw to the left. I tried with gain to 100 and even then did not notice the tail wag ..

I am not sure why my Gyro doesnt lock the nose in one heading, as it should .

BTW had one question, when in HH mode, suppose you lift the heli and move it to a different place / direction, the gyro would be trying to rotate the heli in the original direction. How do you reset this ? perhaps by switching to rate mode and then back to HH mode ?

On Futaba, the gain values are translated directly as in 0 to 100% is the same on the gyro, as it is on the radio (for both HH and rate modes). 

Apparently you are doing something wrong :) 

First of all, since this is a HH capable gyro, you should set the "MODE" to "GY", have you done that ? (For a non HH gyro, you will keep that at "STD" which we don't want in this case).

Make sure the whole gyro thing is "ACT"ivated (moved out of "INH").

Then, as you change the gain number alone, you will see it moving between HH ("AVC" in Futaba world) and rate mode ("NOR" in Futaba world).

So all you need to do is put it in "NOR 50%", and get your mechanical setup right.  After that, switch to something like "AVC 40%" and fly.  If you feel slight drifts, increase the gain in "AVC" side until the tail starts to wag quickly, then reduce it a little bit. Absolutely DO NOT PLAY with things like REVO mixing, if you have anything like that, disable ('INH') it right away.

Always remember to NOT move the heli for the first 3 to 5 seconds after you plug in the battery, this is the time the gyro initializes and "learns" what the default/stable position is.

Before i work on tuning this tomorrow, i wanted to verify something.
When i adjust the linkage, in rate mode, my objective should be to  adjust the linkage so that the heli hovers without any drift AND does not require any input to track straight ?
Now this should be done without the Revo mix ( which i have as INH at all times )  ?

From what i read so far on how Gyros work how will this be possible, because in rate mode the gyro merely dampens the yaw movement, so the heli will not immediately swing to the left, but gradually it will keep turning to the left , isnt it ?

So is it really possible that in rate mode, without Revo mix , we can get the heli to point straight ?

Now you are officially declared as reading too much ;D

Yes, it is quite simple.  Go to 50 gain in rate mode, and adjust linkage or servo position till you fly without any drift or rudder input.  Forget you ever learnt the word "Revo" for now ;)  I never brought it up for discussion, if you remember.  None of that is needed.

To oversimplify it, HH works better because it can handle the effects of wind, pitch, throttle & rudder input better; because of its ability to remember/calculate the orientation it needs to hold.  Rate mode itself can hold the tail without any drift, given favorable/reasonable wind and main blade rpm/pitch conditions. Rate mode is affected by sudden pitch/throttle changes, but that is not the case in either hovering or stable forward flight; so for your test in rate mode, the simple answer is that it will hold pretty well in a hover. Point the nose of the heli into the wind.

If you continue to read about Revo mix, you will realize that is old school, when gyros like the HH ones now were NOT available :)  If you want to read about Revo-mixing, here you go :

http://www.raptortechnique.com/gyroinfo.htm

Anwar, what is the need for rate mode to be included in an HELI GYRO when there is HH mode?

For one, it allows you to do the mechanical setup properly. 

I also read about some pattern pilots using rate mode, although never found a really good explanation for why that was called for (or may be I did not look enough!).

One example is when you do a roll on FF. In rate mode, the tail "weather vanes" to make the roll more axial. In mode 2, it is easy to introduce tiny bit of rudder input when changing pitch for the roll. Rate mode hides this to some extent.

Just looked this up, thank you Rajesh.

http://www.rchelicopterfun.com/heading-hold-gyro.html  (see the headings "Heading Hold gyro limitations" and "Heading hold gyro benefits for aerobatics").

Also, elsewhere someone suggested that rate mode may actually help beginners with forward flight, as the weather-vane effect will keep the tail in line with the direction of flight, without the flyer having to "fly the tail".

PS: I like this sentence from the last part of that page, which reads :

"A lower quality HH gyro paired with a fast digital servo, will outperform the best HH gyro paired with a slow analog servo."  Reiterates that a good/fast servo is a must for good tail performance !

Ok, i managed to get the heli to point straight in rate mode, and with no rudder input !
I had to tweak the length of the pushrod to achieve this but i think its good now. The servo arm is also perpendicular to the servo/boom.

I got the heli back in HH mode. I am still not too happy here. I get some uncommanded left and right movement, depending upon the gain setting.

If i let the gain too high eg 90-100 i get the heli to move to the right with tail wags ( moves to right with jerks )  and if i set the gain low to something like 20, there is no wag but the heli wants to turn left. In between at 50-60 gain as well the heli does not really stay locked in to one heading. I mean ideally i should not be needing any rudder for the heli to stay in a 1 minute hover, right ?
The rudder trim/subtrim is 0 and revo mix is INH, and all other mixes in radio are off ( except the gyro gain, throttle hold which i enabled ) .

I run out of battery time , since i have only one pack, i get to do this testing for only about 5-6 minutes at a time .

Any ideas ?

It is possible that it is your thumbs doing it inadvertantly :) 

Adjust your THROTTLE curve so that you can hover without any throttle adjustments (ie, without the heli going up or down) at some throttle stick position, and take your thumb off the left stick completely and see if it still drifts.

I had thought of that !!! When in a hover i moved my hand away from the throttle/rudder stick , even then the heli wanted to turn itself ... :((
I also checked the vibration. but I do not think that is too much ..

Hmmm. Usually, HH will mask many setup issues.  So I am pretty sure you have missed something in your radio setup or how the heli receiver is wired up. Just need to hunt it down. 

One more suggestion.  When you switch from rate to HH, fully shutdown both the heli and the radio.  Power up the radio again in HH mode, then power the heli back up, wait for it to initialize (3 to 5 seconds) and see if it holds better.

I think its a issue with the gain channel.
When i connect the gyro gain wire to channel 5, and switch the gyro to HH mode using the TX , with any gain amount, and the heli staying on the ground i see a servo creep to the left .
If i try this without the gain wire connected, there is no creep.

Now while flying i have been observing that the heli is wanting to turn to the left in HH mode. This co-relates to the servo creep i am seeing.
Tomorrow morning i will fly without the gain signal wire connected to see how the tail performs...

Came across another thing today. I wanted to adjust the End point of the rudder servo, so that the maximum travel on either side does not cause binding.
Now, i switched to rate mode, and adjusted the dial on the gyro (the potentiometer) so that with full left and right inputs the tail pitch slider does not reach the ends.
However, since my tail pitch slider is offset to the right in the neutral position ( as you suggested in order to get the heli to track straight in rate mode without input ) , i need to set the EPA to quite low, to avoid the tail pitch slider going to max right, but what that does is , it does not give full travel to the left. If i adjust the EPA for the left travel, the servo binds when it goes to the right.
I think the EPA should be set differently in both directions. but the gyro doesnt support this ?

Also, i have been downloading and watching the Bob Finless videos, the beginner ones. In one of them ( i think the Gyro setup ), he has said that for tail setup, in rate mode, when the stick and trims are neutral the arm should be perpendicular AND the pitch slider should be exactly centered.

Isnt this contradicting to what we have been trying to do here - get the heli to track straight by giving some right pitch in neutral condition ?

 

It is normal to have the offset on Raptors. Just set it so that it doesn't bind. Using less of the available travel on one side is not an issue.

Bob has multiple videos.  There is one where he uses a Telebee gyro, which is a very low end gyro.  If you watch the right ones, you will understand what he is suggesting is the initial setup for HH (set the tail slider perpendicular, use HH and fly). Later, he does clarify that you should set it to rate mode and adjust mechanically, then permanently move to HH and fly. 

About end points, you will typically never go that for the purpose of preventing the slider hitting either end.  People reduce the end points to slow down how fast you can pirouette using the tail.  Whether the tail slider hits either end is prevented by adjusting a "limit" pot on many gyros, and not using end-points in the radio.  On the TG6100M, you should use the "EPA" pot on the gyro to do this.  Most gyros recommend that you use an appropriate hole on the rudder servo arm so that the EPA ends up being around 80% of the maximum available for that pot ("EPA" pot on TG6100M, "limit" pot on many other gyros).

Ok, i hovered today with the Ch5 wire disconnected and the gyro in HH mode and the gain on the pot set to 50. There was a very slight drift to the left. Like 45 degrees in 10 seconds. Is that kind of drift normal ? ( i am new to gyros so may be expecting a lot from them ! )
Funny thing is that with the ch5 wire connected, there is even more drift to the left . I tried the gain on the radio at 30,50,70 but it didnt really help much.
The manual for this gyro doesnt clearly indicate how the Ch5 is used. and i couldnt really locate more information on the internet.
At this point, I think i am going to fly in HH mode, with the ch5 disconnected and move on to practice side hoverings.
I am pretty good with tail in hoverings and have been moving the heli forward-backward .

No, a HH gyro should not drift that much (at least not in a consistently reproducible manner), without pilot input. Please double check everything, including how well the gyro is mounted (funny things happen if the gyro encounters vibrations, for example if the double side foam/tape used to mount the gyro has gone weak etc).

There are multiple threads online about people using the green wire to fully control the gyro (for both mode and gain settings) remotely from their radios.

Had a crash today. Was trying to hover the heli with its side towards me and man that looked so tough ! I have the tail in hovering very well practised now. I can keep the heli just at one place with barely any stick movement. Also i do forward - stop - backward - stop.
Broke the main blades, the stripped the main gear. Had replacements for both and got it back in the air in 20 minutes :) :)

Lesson learnt - not to be over confident and take things slowly. Will be practicing sideways flight in the sim more before trying out in real.

Take it easy Gaurav :)

Remember to fly in a large open area, and try any new moves/orientations at a bit of distance from you and at a good height (but not too high or far that you cannot see the heli orientation properly).

Gaurav, my suggestions, throw those training yellow balls and use ping pong balls if they can stand the weight. What I noted was that those yellow training balls hold on to the grass etc when lifting off, giving a feeling that the Heli is not trimmed >:D.

Vinay,
Somehow i like my training gear, and i think it has saved me a lot of crashes so far.I purposely do not fly off grass just for the reason that when getting into a hover gradually, the training gear catches the grass and spins the heli sometimes.

BTW, as a long term airplane flier, and now just starting helis i notice a few things i am doing, out of habit, but is not well suited to helis :
- When in a even slightly dangerous situation, out of habit, i seem to pull the throttle back. Also i have seen that instinctively i also give in up elevator .
- I need to learn to give 'pure' inputs. Most of the time i have seen that when giving an aileron input i am also giving some up elevator. When practicing hovering, i need to learn to give pure inputs.
- Not so much used to backward flying

I learnt that side hovering needs a lot of practice, and have come back to the sim for that. Somehow on the sim i can do a good nose-in but side hovering is still something where i crash very often. I think this is because i am not used to giving true cyclic inputs yet.


Now one question. I wanted to see if my blades are tracking properly. For that when i get the heli into a hover at eye level, I see the flybar 'disc' clearly, however the main blade disc is not very clearly visible. Its kind of fuzzy. Do you think this means my blades are out of track ? Note that i am using wooden blades and the tips arent painted , they are natural wood color.

Wait till you go back and fly planes. I was cutting throttle (negative pitch in heli) when going inverted :o

Backwards is not as simple as one would think. Backwards when tail is pointed to you is natural flying but doing a full backwards circuit or fig 8 takes some practice. Don't try it on the heli first, try on sim.

Plane flying experience helps too in some cases. I was very comfortable flying FF circuits like a plane. Even nose in attitude, but I couldn't do a nose in hover at that time confidently.

If you cannot see the blades properly try against a different background. They should be in the same plane, not fuzzy. But woodies are sometimes difficult to track, one flight they'll be perfect, next flight they'll be  bit off.

Thanks Rajesh.
One question. These wooden blades come with a Thunder Tiger decal, one red and one black. If i put these on top of the blades, would it help to 'see' them track ?
Or would i need to put them on the leading edges to see them ?

The way we typically use those stickers is to identify which way to change the linkage rod lengths (tighten them or loosen them). 

So you take the heli to eye level hover, and see if you see two separate "disc"s being created by the two blades.  If there is only one disc from both the blades, you are all set.  If there are two separate discs, we need to adjust linkages.  So put the colored tapes on one of the blades to mark it, and hover again at eye level.  This time you should be able to identify which disc is higher and which one is lower.  Adjust accordingly until you have only one disc.

But you can do this without those tapes also. Just note one blade using some *existing* nick/cut/marking on the blade or the blade holder, and adjust by trial and error.

I have also seen people use bigger tapes to balance the blades.

Had a great time today.
Yesterday my parcel from HobbyCity arrived with 3 Turnigy 2200maH 3S Lipo batteries.
They are smaller in size, compared to the Ace Hobby battery i have on the mini  Titan.
As on the website all batteries came with the XT-60 connector, which is what i am using on my heli and charger too.
The batteries were half-charges ( exactly ! ), and after charging, i had 4 battery packs !!

I took my heli to a nearby field, and got a good 10 minute flight from each Turnigy Lipo.
Note that the Ace hobby battery struggles to give me anything above 7 minutes flying . And i am just hovering as yet.

So i did 4 flights today and adhered to tail-in hovering, along with practising tail-in circles, and go-left-stop-go right-stop manoevers. Also tried to do some side hovering, but i need some practice to gain confidence.

I am sure my servo setup/trim/subtrim is not optimally tuned yet, but i will tweak that later, when i have had some practice on this.

At this point, i am just enjoying flying, and plan to go every morning, since the field is barely 2 minute drive away

Charged my new Turnigy batteries, and they took in around 2200mAh Wow ! My Ace Hobby batteries were taking in only 1650 mAh . I guess these Turnigy batteries pack in more mAh then what says on their specs.
Now lets see how they fare over a period of regular use.

Bad idea to discharge them that low.  How many volts was across the packs when you started the recharge ? 

Also, there is some discussion that lipos have also a "break-in" ("conditioning") for longer life by charging at 0.5c for the first few charges, and discharging them only to half the rated mAH (although this is debated).  In any case, too deep a discharge is really bad.

I am not getting them too low. The charger read 10.5 volts when i put them on charge.
The ESC cutoff is set to normal for Lipo, and as soon as the RPM seems to quiver i land the heli.
On my ACE Hobby 2200mAh battery pack, i am regularly using and putting in around 1650 mAh, but on the Turnigy i somehow used around 2100mAh and the voltage still read 10.5V

I will make a note to charge them at .5C for the next few times.

I had 4 flights today again. Getting more confidence. Started practicing side hovering too. I think i have it pretty much when the heli faces the right. But when it faces the left then i still cannot give the correct inputs.
I guess practice will make me perfect.

Now i did do some forward flight. Slowly got the heli to go left and then right. Got most of it fine, but need some more practice controlling, when the heli faces the side.

I read on Raptor Technique website to try and practise some easy auto-rotations from 2 feet or so. I will be trying them next time i fly, as i will need to adjust my Throttle hold curve for that. I intend to make the TH curve the same as the one i fly with, and try doing autos from two feet, by just hitting the hold switch.

Now the sad part. I wont be able to fly till next week. got some travelling/work to do. But hopefully will be back very soon and continue learning.

I am tempted to install my RealFlight on my laptop and practice when i get time in-between work/flights.
Now thats called heli-mania in the true sense.

Got back today. Hovered the heli this morning. All looks good, but somehow i am still not too happy with the gyro's headlock. I am thinking of swapping this with a HK one to see if its a gyro issue.
Anyways, i should be practicing daily now. Will get some pictures soon as well.

Been flying regularly now.
One question i had was, since my last crash, i noted that the hovering time has reduced  from 8-9 mins to 6-7 mins. Now the batteries are fine, since they take a charge of around 1800maH . The motor feels a little hotter than before, so perhaps its something there. The main shaft was changed on the last crash, so that cannot be the culprit.
I think it would be :
- Feathering shaft ( can this cause excessive battery drain ? this was not replaced, but the hovering/flying is normal )
- Tail rotor shaft. I have a hunch this could be a culprit, as though it was not replaced, i have noticed the gyro acting funny sometimes. There is a little vibration on the boom at 20% throttle, but goes away at 50%. What would be the symptoms of a bent tail shaft ?

What else could cause a shortened battery life

Please dont tell me that the bearings have gone :):):)

Changed the tail rotor shaft today. Not much difference. Getting the same 6 minutes.
Inspected the belt and tension. All ok.
Now i am doing some forward flights too. Very little though could that make a difference ?

is the belt too tight? or is the motor gear too closely attached to the main gear? not sure if these may cause problems but i Have seen that when these are thight and when i turn the rotor in my hand, its a lil hard.

Vinay, thanks Will look at that today. Should i bother replacing the feathering shaft ? could that be an issue, or perhaps work on blade tracking ?

y dont you check the current consumption using a watt meter?

I do not have a Watt meter. This is my first electric model, so i will need to get one soon now. I tweaked the heli and i think the belt was too tight. I will fly this tom morning to see, but I read through several forums, and i think it should be better now.
Will post here the results, first thing tomorrow.

BTW is your HK450 T back in the air ?

It was built long back but could not goto jakkur. will fly this sunday for sure ;D also awaiting the plastic 450 for that careless flying. :giggle:

Ok, I loosened the belt yesterday and also rechecked the motor pinon-main gear mesh.
It made a huge difference !! Got back my 10 minute flying. Thank you so much !
I didnt know that a tight tail belt could rob so much of power !

Even I didnt know that was a issue, I just suggested that based on my experience with turning the rotor with hand with a tight belt :giggle:

Also was your pinion-gear mesh tight as well?

BTW I am getting good at side hoverings. SO now i can hover for the entire battery pack, with the heli pointed straight left or right. I am happy with my progress so far. Just a month back, side hoverings looked so tough !
Also practising little forward flights. Coming from airplanes one thing i realise, is that with helis you can loose orientation much much easily. So very important to keep them at whatever distance is needed for a clear vision.

I have 4 battery packs, and so did 40 minute of flying this morning , and will do the same in the evening.

One more thing, i would like to share, is that mini Titan is a "Terrific" heli. Rock solid, and good quality parts. The price isnt that much too, so I would recommend this heli to everyone. The spares arent that expensive too.

pinon was not that tight. The main culprit was tight belt.

Orientation wise Iam can fly in any direction any minutes, though I get confused 10% of the time. Tail in nose in, sides are no prob on hte sim. Practising inverted hovering tail in now. You are lucky you get practicals every day :thumbsup:

On sim, I can do Nose-ins for a long time. But in real I still get nervous.
I think practise will improve.

BTW Is it a good time, i should move to using the the full pitch curve ? Ie the Ide-up one ? Right now my pitch curve is -2 to +10 and hovering at midstick.
Would it be better for me to change and practise with the idle at center stick ?

Ujjwal always used to say sim is not a very very good idea, though he supports sim upto an extent, I recently visited his house and tried playing G4.5 on his 4 year old Laptop. It was crap. I couldnt even hover my favourite heli for 10 seconds believe me. THe Frames Per Second was around 8 to 10, and it was jerking. The graphics was crappy. Not even grass was displayed properly, forget the CPU expensive physics calculation-simulation. The PP Joy connection he had made was working like as though he had set the TX on -ve 80% exponential. No wonder many people hate it.

G4.5 requires a high end system to look good and the physics to work best. You have to select in the options to simulate good physics.

I have a high end gaming system with 4gb ram 22"LCD and a 512MB GeForce 8800GT series graphics card with a very good DYNAM 6Ch simulator. And it really rocks.

Tomorrow I will know the diff b/t sim and real for real, since I have better orientation now, I can confidently hover, if I find Rajesh in time, before I loose patience and start trimming myself.

Oh God, give me some patience. :banghead:

If someone wants to go with this heli, i would recommend reading through this entire thread. Has a lot of valuable information

http://www.rcuniverse.com/forum/m_5974113/mpage_1/key_/tm.htm

My mini Titan's ESC has an option I do not understand. It is Flying mode :
Helicopter with governor
Helicopter without governor.

What is the difference, and advantages of each ?  What should i use ?

I read about it some time back. Its like its tries to keep the head speed constant under varying load and eat batteries, does not allow the heli to boggle. Not sure if governor can be used on 0 50 100 throttle curve.

EDIT: Did some reading and came to know that its used to set a flat throttle curve. SO when flying no matter how you fly or even in 3D, the governer will maintain that same head speed. So no need to have that V throttle curve if using governer. Beacause of this flat curve, rather than the V curve or the beginners 0 50 100, governors tends to eat up more batteries.

Did my first nose in hovering today.
Was only for a few seconds before i got nervous, but at least i started on it !
I do not have anyone around to make a video or take pictures. I am thinking will put my camcorder on a tripod and then fly.
3 flights down and hope to have at least 6 more today.

Guys,
I did a total of 7 flights yesterday in my garden. I am now being able to confidentially hold a hover with tail in , and sideways with both sides. I am also doing some forward flights, as you can see, and next target is to master nose in hovers.
Then i will be attempting to do squares ( or rectangles ) .

Following that, will go to a bigger field and start doing stall turns etc..

Anwar, Vinay, Rajesh and all other heli fliers, please do comment on my video, on what I can do to improve.
Thanks
Gaurav
Oh, here is the video :
http://www.youtube.com/watch?v=-8N-YVVNAC0

It is natural for most people to get into fast forward flight and smooth figure eights before they do nose-in hovers. 

Either way, I would strongly recommend that any significantly new move should be tried at a bigger field, with the heli at a higher altitude than what is you are flying in the video :)  For banking turns with both aileron and rudder, you definitely need more altitude to recover in case you get disoriented.

Also, it seems you are always turning in the same directions (left turn when the heli is on your left and right turn when the heli is on your right). This is OK for now, but you should make a deliberate effort to do it both ways at the earliest.

Thanks Anwar.
I am keeping the heli low, so i can land in case i get disoriented. But i will go to a bigger field and practise, but after i am confident with nose in hovering.
I have found that going to a bigger field, gets me more relaxed, and hence invited trouble. I go to far, get disoriented and crash. With a smaller space, i feel i am learning to fly in a much more controlled manner. I havent crashed flying at home, and yet crashed thrice on the field !

Regarding turning, When the heli is on my right, I make a left turn and when its on the left, i make a right turn.
THis is to avoid getting the heli to nose in .

When the heli comes nose in , i do get a little nervous but i guess will be better after a few flights.
 

Whether you realize it or not, the heli is already nose in for about 50% of the time ! It is not in a "nose in hover", but it is "nose in" !

The way you are turning give you the feeling that the heli is "turning away from you", which is comforting to many (the same applies to airplane flying), but it seems to have not much to do with "nose in" itself.

I still do not think that in the above video I got the heli to face me nose-in at any time. It was either with the tail pointed towards me, or one of the sides...Yes i am turning away from me on both left and right, and that is to avoid the nose-in at which i am not very comfortable at this stage.

What I meant is from a "heli coming towards you" (or "closer to you with the head of the heli leading the way") perspective, which is exactly what happens in a nose-in. You right as in it never directly pointed towards you, but the way you apply controls is the same.

So what you are NOT doing is a "nose in hover", but you are already controlling it as if it is in a "nose in".

I get what you are saying. After i practise not getting nervous with the heli facing towards me, i will start doing turns on both sides.
My next agenda is to get the heli to hover with the nose towards me and keep it in one place so i can get comfortable in that orientation.
Of course doing everything but not crashing !

Where did you buy this from? How much did you pay?

I came across this : http://www.littlerotors.com/flyinglessons/index.aspx
Looks like some nice tips for myself, Vinay and other heli learners

Thanks, Its really good. Just what  I needed.

Getting better with nose in flights now. Its amazing how fast our brains train. Just last week i was getting nervous with the heli facing me, and today i can hover for more than a minute.  Nose in hover is still tense for me, and i guess some more practice would ease off the tension. I think when we are strained we tend to make more mistakes.

Also the eyes need to get used to the way the heli looks from various angles while hovering. When in a nose-in hover the heli looks even more tilted to the right. I guess thats because of the perspective.

Another nice article. Worth reading for all people starting with electric helis

http://www.swashplate.co.uk/ehbg-v17/ehbg_index.html

Though i am flying the heli nearly everyday, I am still not too happy/confident about how the tail is holding. I look out to Anwar/Rajesh and all others to try and help me out here. I will try to describe the problems and experience in a detailed way to help debug this out.

Problem : Every time i take off, i feel that there is a tendency for the nose to turn right, though slowly. When I give 2 clicks of trim it holds better. Of course the next time i initialize i would need to reset this trim in order for the gyro to center itself.
Then while flying sometimes i see the heli wanting to turn itself again ( again very slowly ) and i need to compensate with the rudder input to hold.
Overall i feel that the tail does not hold rock solid, as i expect.

Facts : Using TG6100 Gyro with Ace C0915 sevo ( not digital )
Using the Gyro Sensitivity on the Futaba 10C. Tried various gain settings 10,30,50,70
Note that in one of my earlier crashes, the flybar had hit the gyro, though it was not physically damaged, the foam had peeled of the back, and i had glued it back.

I have the servo arm perpendicular in rate mode, and have tweaked the linkage length/servo position so that I can hold a hover without any rudder input.

Also tried various headspeeds on the hover, but same experience

Also i take due precautions to keep the heli steady on ground till the gyro initialized, and take off from the same place ( and heading )  where i initialize,

Options i see :
- Gyro damaged ( just a possibility )
- Servo damaged ( could this be ? )
- Need to change the position of linkage ball on servo arm. The limit pot on the gyro is set to 50 ( this is to avoid the pitch slider touch the ends in rate mode ) .
- Something that I am not aware of yet... Please enlighten !

Thanks !

was it holding before crash?

Well, was kind of like this only, maybe perhaps a little better.

Well ok, i am loving this heli and now being able to do  figure 8s and circles and side + mode in orientation for a long as i want. I can take off nose in and land anywhere in any orientation.
My next steps are to take on rolls and loops.
However the pitch curve i a using is linear between -2 and +10 and the throttle is 0,80,80,80,100 I think i should change and use the idle up setting.
Should i use the 2 modes ? or just use one mode with -10 to +10 pitch curve with hovering on 3/4th throttle ?
I know there are two schools of thought here. but would like to do whatever is good in the long run.

Thanks !

Single/same linear curve in all flight modes, including throttle hold.  How can you be sure ?  Ask anyone who has been flying helis seriously for a while :)

BTW, your normal mode throttle curve is sort of weird.  You certainly do not need 80% throttle at the 25% stick position :headscratch:

Yesterday while doing some fast forward flights, i observed a few things. WOuld be great if those who are experienced here could confirm if I am correct here :
1. The controls of the heli behave differently when in a hover/slow flight versus that in fast flight.
2. There is a critical point at which this control changes. something like stall speed. If the heli flies faster than this speed, then the controls behave like those of airplane, but if the heli is slow, then the controls behave like that as in hover.
3. Slow flight/ hover is very difficult. If a heli is moving forward slowly and a left cyclic is given the heli starts moving forward as well as to the left, laterally. This does not happen in fast flights, where if the heli is moving forward, and left input given, the heli banks and moves in a circle, rather than laterally.
4. In slow flight, getting the heli at a height, or away is dangerous, as the pilot can easily get disoriented, since the heli can move on any direction. In fast forward flight, its much more predictable can thus can be taken high and far.
5. Getting the heli into fast flight needs a couple of circuits and also to kill the speed and get back into hover needs space,


Let me know if the above observations are correct.

Guess no one was interested in my observations !
I searched around and found that this is related to Translational lift that the heli gets when in fast forward flight.
Havent been able to grasp it all, but would be good to know more on this.
-Gaurav

Not really :)  I was building a Trex 600ESP for someone we all know ;)  And this is a subject that requires some thought !

First of all, I see that it is commendable that you are taking it slow and steady, something like what they say about the Friench eat their food (cherishng each bite/moment ?).  Me personally rushed it when I was learning (mind you that I learned on helis first), so the goal was to get to 3D fast.  I did make sure that I put in time to get my orientations well (for example doing figure 8s both ways, and then doing them in backwards flight both ways).  But I did not stop and think about stall, hover, forward flight differences etc, like the way you are doing it.  I guess coming from an airplane background helps you compare.

Overall, two things stand out about heli flying.  One is that rudder assistance is pretty much needed in all turns. Second is that forward flight is driven more by slight forward elevator in helis, where it is mostly driven by throttle in airplanes.  I guess the second point is what prompted your above observations. 

The lesson I learned over all is that if you spend time doing maneuvers "forwards upright, backwards upright, forwards inverted and backwards inverted", then you are set.  Most people train themselves to do figure eights in one direction first, and many get stuck there.  Finally they move on to doing them in the opposite direction also.  But very few people try to do them backwards.  And that is the KEY !  And if you do them inverted also, you qualify as a true flier !

Helis are easier in general for people to get disoriented because of the low profile (how much the airplane wings help with orientation can only be appreciated when one starts flying helis).  If you get into the habit of watching for the disc made by the main blades, that is another milestone in heli flying.

Regarding the controls being different in hovering versus fast forward flights, I believe a similar comparison can be made in airplane world also... in hovering a plane versus forward flight of a plane.

And as they always say, "one of the tougher maneuvers in airplane flying is to hover them; but that is where heli flying starts!".  I guess this puts the challenges of flying helis in perspective.

You can get a heli in fast forward flight with enough pitch, engine/throttle response and the right amount of forward elevator.  I never felt that it takes multiple circuits to get into fast flights.  Like anything, there is a period of slowness and acceleration, and the capabilities of the heli and the pilot determines how soon fast flight is achieved.  And you can make a heli in fast forward flight stop instantaneously with a lot of backwards elevator (pull elevator stick down to get the nose up) ALONG WITH a quick punch and release of positive pitch.

Thanks Anwar.

I am prone to getting disoriented. The rotor disc in not that visible, perhaps because I am using wooden blades. Any tips/ideas to make this more visible ? Right now, i seem to be looking at the landing skids, and the 4 training gear balls seem to be adding to my problems. Though they make the heli visible they make it confusing to judge the attitude or where the heli is facing.

Looking for some ideas here to aid visibility/orientation.

Helis cause disorientation to everyone, because of the lack of the whole wing structure.  The rotor discs are generally barely visible to everyone, it is something you pick up with time/practice (at least that was my experience).  Some people put reflective stickers on them, but I found them causing more issues.

I have been looking over the net to see what people have to say for my kind of experiences and it seems that since I am coing fro airplanes, i tend to pull back on the stick when I panic/nervous, this causes the heli to loose forward speed  I need to learn to give down cyclic to keep the forward speed.
Some have suggested i give a few clicks of forward trim to assist learning, though not sure if thats a good idea.
Anyways, I hope to keep practising, at least every alternate day and hopefully I will get better at this ! .

Also, i think i might fly my Raptor more than mini Titan. Raptor is much more stable and visible, so might help me in learning.

What head speeds are you using? It is looking very stable!! My HK 450 does not fly like that, The head speed I am using is like 2700s to 2800s and its a little punchy, becomes stable as the battery becomes weak. I need to reduce the head speed. But its more stable than the sim TREX 450 (3200 RPM).

Never calculated headspeed. If i lower the headspeed a bit no difference. if i lower too much it wobbles.
If i increase the whine increases but no change in stability. But since i have woodies on it, do not want to fly at too high headspeeds
Do post us your video of your 450 flying.

Sorry I was flying alone. No videos.  :(