I would suggest the same with the Airframe as well 

Something other than  a YAK , I think every  Gassers around is  YAK 

Sai

Hello uncle,

I definitely agree that most of the gassers are YAKs.  But then I have a definite addiction     towards that model and moreover it is a very well behaved plane compared to the extra or the edge.  Both the Extra and the Edge drop a wing at higher speeds whereas the YAK can be stalled nicely without dropping a wing.  That huge cowl alone is enough to distract me from even thinking of other planes! This would be my 3rd YAK but there would be many more!

- Chan

Chan,
I got a YAK 54 from rcdhamaka, just last week. Its looks awesome. I am still deciding on the servos/ engine, but the plane looks awesome, and the build is light too.

Let me know when you get yours . Ill post pictures of my setup when i start assembling.


-Gaurav

Hey Gaurav,

Did you get the one with the checkered flag on the cowl?  It looks great I know.  There is also a YAK 54 for sale in Chennai which I am considering as I am getting it at a good bargain.  Even that looks great.  Awesome colour scheme.  A little bit indecisive still.  But the bargain is too dear to resist.  It is the same as the RCDhamaka YAK except for the colour scheme.

- Chan

Chan,

On the servos, I see two options

1, Use two servos with lower torque instead of having one servo with a higher torque? The cost may work out in your favour.

2, Other option is to use boost tabs.. Here is a small intro on boost tabs -> http://www.geocities.com/roger_forgues/Boost-tabs.html

You can use a lower torque servo to actuate a control surface having a boost tab... But I am not sure you would dare to experiement this in your first gasser.

-Ismail

Hi Guys,

Regarding the servos, what should be the torque I should be looking at.  Let us estimate the AUW of the plane to be roughly 8 kgs.  A 86" YAK. 

My question is, is a 10kg torque servo enough for each aileron?  And 2 x 10kg servos for the elevator?

The plane uses two servos for the elevator and one for each aileron.

I was initially planning on 5645s (10kg torque MG servos from Hitec) for the elevator and ailerons but was a bit skeptic.  But yesterday I saw a friend of mine with a 50cc YAK (the same one in the thread opened by RCDhamaka - YAK 55 SP flown in Chennai) that had 5645s on the ailerons and elevator and a 5955 (23kg torque) for the rudder.  The planes flying fine but has not been put through much of 3D aerobatics.  I was wondering whether the servos would hold through snap rolls and flat spins after a certain period.

How do I calculate what torque is required for the servo?  I was hoping for a 8kg plane, 10kg servos should be fine except for the rudder.  Any comments anyone?

- Chan

Hi Guys,

Activity started on the plane.. Finalized and picked up the DA 50 yesterday evening.  It has been run on the ground for half a tank and it has flown two sorties on a World Models Extra 330.  Owner didnt like the combo and retired the engine.. That is the history of the enigne.   Hardly two and a half tanks have been run!! Engine has been neatly packed and maintained.  No stains, no marks or scratches.. Everything is in mint condition.. Packed in dual plastic covers and sealed in a cardboard box.  Got it for a nice bargain from a really helpful person in Chennai!!  Would post some pics soon..

The box contained,

1. The engine with the spark plug
2. The standoffs without mounting bolts
3. The ignition module
4. The switch
5. Some misc hardware

Would start work on the model soon.  Having all the critical joints strengthened and clear coat sprayed this weekend.  Then would start the mounting. 

Please give me some suggestions for dampening the vibrations!! And also some building tips on these 50ccs would be really helpful..

Thanks..

Regards,
Chan

Posting some pics of the engine..

Great pics. I am waiting to get mine ( thought would be a few months later ) .
BTW what Rx battery pack have you thought of using on your gasser ? Lipo or A123 ?
You got to be very careful when setting up that beast ! I was thinking of dual switch and dual battery packs ...

-Gaurav

Hi Gaurav,

Even I am going to put in dual switch with dual packs.  There is a special switch for that purpose.  It is called a Miracle switch.  Just search for it.  I think it just helps in connecting both the battery packs in parallel.  So both of them are connected to the Rx in a sort of Y parallel connection.  In this case, even if one pack fails, then the other pack takes over and similarly when one pack runs out of charge, the other one would handle the Rx power!!  I would prefer A123s but am still not familiar with the technology.  So I think I would initially go in for Lipolys (direct 7.4V 2000 mAh) since both the Rx and servos can handle high voltages and I would not use a BEC!!

Parallely, I would start using A123 packs on my 40 size planes and electrics to check their reliability (not that I doubt them)!!

What engine have you finalized?? I think the best bang for the buck is the DLE55 or the MT 57 right now.. and DLE has better support and spares availability!

- Chan

Chan,
Which Rx will you use ? Not sure Futaba FAAST ones can take 7.4V directly ?
I have not yet finalized the engine yet. If i get a good deal in US i will get it from there, otherwise will buy it a little later.

Have you thought of using a smoke system ? It would look cool with a gasser this size, plus the engine would be generating enough heat to run it.

7955TG seem to be great, but they are expensive. but perhaps i will also go in for them,. I have read a bit on Metal Gears and not sure i seem to like them too much

-Gaurav

Hey Gaurav,

I also have to check whether FASST Rx can take 7.4 direct.. I know very well that Spektrum can handle it well.  If not, then either use BECs or use A123s.. no other option (NiCd is not an option for me  )!! And moreover, the ignition unit for the DA 50 is not meant for 7.4V direct.  It can take a maximum of 6V.  So I have to use a BEC or a A123!!  Just checked the DA manual!

Moreover, the 7955 TG are available for 89 USD at http://www.chiefaircraft.com .  You can probably get a better deal with them if you can bargain a bit.  80 USD for them is actually a very good deal.  See if you can land up with them!!

I have already decided to put on a smoke system but only after I break in the engine and get it running smoothly.  I would take another 3 months atleast to put that in.  I might get a pump though now itself.  DAs are meant to have atleast 5 gallons of fuel through them before you can call them broken in.  Thats roughly 25 litres of petrol.. 2 litres a week would mean 12 weeks or 3 months time for just breaking in the engine!!  I can start ripping only after that..  Then comes the smoke system.. Would device it something like a snap-on, so that it can be removed easily whenever I want to.  Dont know the entire mechanism though.  Should start reading up on it!  Post some pics of your model dude!! Would be great to see it on the site!!  Just dry assemble eveything and put up some pics!!

- Chan

Hi Guys,

I have acquired pretty much everything to start the build now.  Let me put up a sort of a list that anyone setting up their first gasser would find very helpful.  Someone let me know if I am missing something so that I can acquire the same before starting the build.

1. Nitro Models Yak 54 50cc Airframe
2. DA 50 Gasoline Engine with Ignition, Standoffs, Muffler, Switch and Spark Plug
3. Futaba 10CHG Dedicated 2.4 Ghz Radio
4. Futaba 8 channel high speed Rx (6008)
5. Hitec 7955 Titanium Gear Coreless Digital Titanium Geared Servos - 5 nos.
6. Hitec 5485 Digital Servo Karbonite Gear for Throttle
7. XOAR 22 x 8 wooden prop (yet to be purchased)
8. Heavy Duty Extensions (36") - 2 nos.
9. Heavy Duty Extensions (24") - 4 nos.
10. Aluminium Spinner 3.5"
11. Rx / Ignition Power Supply (Either Lipo with BEC or A123) (yet to be purchased)
12. 2T Engine Oil (Either regular 2T mineral oil or Pennzoil)
13. Heavy Duty Switches - 2 nos.
14. Battery Connectors
15. Reinforcement material if required
16. On Board Voltage Checker (yet to be purchased)
17. Misc Hardware like Zip Ties, Double Side Tape etc.
18. Good Epoxy (Araldite should be fine)
19. Fuel Can
20. Fuel Pump for Petrol

I think thats about all that is required.  Build would start this weekend.  Would keep posting the progress.

- Chan

would love to have some pics too

Would post some pics of all the setup I would be using.  Hoping to celebrate my first aeromodelling anniversary (Jul 27th) with the YAK.  In another month, I would be marking my 1st year of entry into aeromodelling !!  Attaching some pics taken on July 27th 2008 when I flew my first solo (that was the day when I had my first takeoff / landing / learning)!! before that I would just take the sticks from dad high up in the air and hold for a min or 2 and give it back... But on this day I was literally forced to do my first takeoff, landing and solo flight including loops and barrel rolls!!  The easy star rocked and proved to be a solid learning companion helping me to progress to a 50cc in a year !!  My line up of planes in chronological order..

1. Easy Star
2. Great Planes Electrostreak
3. World Models Cessna
4. GWS Tiger Moth 3D
5. Flight8 Yak
6. Seduction
7. Megafly
8. Yak 55 .50 size electric
9. Nasty
10. Phoenix Funstar .40 size
11. Hyperion 3-Delight
12. Thunder Tiger Christen Eagle
13. Techone Katana
14. King Kobra .60 size

- Chan

Hi Guys,

Starting work on my gasser today..Got the wing and the elevator halves on the table now.. Today's agenda is to finish hinging both the ailerons and the elevator halves..

Would have to chart out a building plan (which I definitely know that I would not stick to!)..

Day 2:

I would start servo mounting on the ailerons and the elevator tomorrow!!  The rudder hinging / canopy sticking would also be done tomorrow..

This would be followed by rudder servo mounting..

Day 3:

The difficult part of the engine / ignition / cowl mounting would be done next..

Day 4 / Day 5:

The tank / Rx / throttle servo and the all the misc stuff would be done last..


This is supposed to be a 5 day plan!! But not a 5 continous day affair!! Would probably work for 10 days to get this finished.. Would post the build thread side by side!!

- Chan

And heres a picture of the exact color scheme that I have!

Chan ,
Do you expect me to believe that 

Knowing  normally day 2 is maiden , considering the  price and the size I would be fairly confident of a Day 3 Maiden at best the coming week end .

Looking forward to the flight report in a day or two

sai

Hey Chan,
The color trim on your YAK looks cooool ! Way to go.!
Hope you get yours up and ready soon now. BTW i was surprised to know that  its been just one year since you got into aeromodelling !
Given your skill in flying and your aeromodelling collection. I think its an achievement .

Good luck with the build, and keep us all posted !
-Gaurav

great chan bhaiya looking foward towards the build

Please correct me if wrong, I was reading up on gas engines and also went through the link you posted. Are basic smaller engines like 23cc and 26cc 2 stroke engines as complicated as the bigger 50cc ones?

I have heard that although they are very sensitive to needle turns, once they are tuned, the carb needs no further changes unless you are looking to derive more performance. That was the primary difference, the article mentions compared to glow engines. It also says weather changes dont affect the tuning much like glow engines.

Also note, I was reading about CY and Zenoah 23cc or 26cc engines that comes on 1/5 scales.

hello uncle...

thats how I would have liked it!! But the epoxy used for the hinges alone take a day to dry on each side !!
Moreover, there are loads of things to be looked into! But still the temptation lingers !!


Thanks for the compliments Gaurav.. Would definitely update this thread with the build!

Thats right!! The needle settings are best left untouched!! They generally need no tuning at all.. The factory settings are almost perfect.. Even if any tuning is required, it is an one time affair!!

- Chan

Hi Mail,

Yes, gas engines are very sensitive to needle changes. If they are sensitive then there is a strong possiblity that there are some dependencies and you might need changes often. Most RC gas engines have diaphram type carbs which operates on pressure differences on both sides of the diaphram, so clearly, they should be having some dependency on weather change and altitude differences (Atmospheric pressure). Further, the engine performance also changes once it warms up to it normal operating temperature. May be for these reasons even the full scale WW2 type (piston engined) planes have mixture control that could be changed by the pilot depending on the weather/altitude conditions. I doubt if you could leave the settings as is after the first tuning. I am sure you would be tempted to retune the engine as you would feel like- Its not what its used to be.

Frankly, I seldom retune my glow engines once they are set. Most of the time they are on the spot no matter what the weather conditions are.

Methanol has a wider flash point than petrol. Its not too fussy about the temperature and pressure changes. However, pertrol has a very narrow flash point and will not ignite (or ignite early) if the conditions are not in its operating range. - This is what I learnt when I was working on the pulsejet project. Don't ask me the flash point figures as I conviniently forgot all of that...

-Ismail

hey chan bhaiya you must have seen this but just thought i would post it here

http://www.flyinggiants.com/forums/fg42/7743-nitro-models-yak-54-3d-build-thread.html

Pikle6,
Thats a .50 glow engine model !! What Chan is building is a 50 CC Gas airplane . Almost 10 times bigger in size !
-Gaurav