Hi All,

Im going to build a tricopter for my FPV,

Im going to need all your help for the same,
I knew a little about multicopters but still need a lot of Inputs from you all.

I have the following:
i.Tricopter frame,
ii.KK2.1 board
iii.power splitter for 4 ESC

1)Now i need help on motor and ESC .
   Im planning  on either of these,
   1.Turnigy D2836/8 1100KV
    2.NTM Prop Drive Series 35-30 1100kv
    Please tell me whichever is good for this. and also in my budget, i can spare upto 4k for 3 motors.

2)Also what capacity and C rating of battery is good for Tricopter.
  I have a Turnigy 2200mah 20C battery. is 20C enough for three motors, or what is the optimal C rating needed.

3)In the video of Flitetest David says it doesnt requires CCW prop for Tricopter, but uses CCW prop combination for himself. also in the KK2.1 board the motor orientation is such that it needs 2CW and 1 CCW prop. any idea or suggestions on this.

4) IF normal props can be used does anyone has any experience on APC props. i always see people using Slowfly props. cant we use APC atleast 2CW and 1 CCW.

Well, thats it for now,

Ashok.P

1) Why did you zero in on those two motors? I am using Sunnysky motors, and would recommend you to use them if possible, And it will also fit in your budget. You can use it with 2S and 3S lipo if AUW is below 800gms(more if using 3S). Im getting 13mins flight time with 20C 2200mah 3s lipo and 23mins with 2S 30C 4200mah lipo approx.

2) C Rating will depend on the motors/props combination you are going to use, both the motors you suggested pull on 15-20 amps on average with a 10*4.5 prop so a 20C 2200mah would really put you in a tight spot. Go for 30C or more.

3)For props use 2CW,1CCW as mentioned in kk2.1 layout, Im using the same and no issues. You can use other combinations but would have to change settings on the board.

4) I think its because of the availability of the slow fly props in excess the reason for using them, also availability in various sizes in CW/CCW too may be the reason. You can use APC multirotor props if you can get your hands on one.I think the most used prop is 10*4.5 size.

1) Im planning to put a Chinese cam on it, its similar to GO pro in function with 12MP mentioned on it but has only clarity of 5MP but can record video simultaneously with a 2GB memory card, the video speed is awesome, weight comes around 300gms for the camera alone not including the video cable and power cable needed for them which shoots up to 400gms in total. good for a cheap price of just 2000rs in bazaar. im planning on Sunny sky too but havent heard of its name yet, but nothing i bought from Quadkopters have gone wrong so i can consider that, but Sunny sky, NTM, Turnigy D2836 all fits in my budget perfectly. can it pull around a KG comfortably...

2)buying a new battery depends on your answer for the first question.

3) i already have 3 CW APC props, but will buy 10x4 SF cw/ccw combo for sure. and try both of them and post the results.

Ashok.P

1) AUW of 1kg with 3s lipo should be manageable for Sunnysky(SS) motors from quadkopters. You can also increase the size of props by an inch(11") if you dont intend to push the quad too hard i.e less max throttle.

2) If you use SS your current battery will suffice, max amperage is 16 with 10.4.5 3S lipo approx. But you will get more batteries once you start flying around

3)Im not sure but you can use 3CW or 3CCW props with some changes in settings of kk2.1 . I dint try it because in the beginning wanted to keep is as easy and simple as it can be.

And link me to the camera you intend to use, also you can remove the cover of the camera and maybe power it from onboard lipo to reduce some weight if possible. Or can go for a Chinese keychain camera available for Rs400-500 @ebay.

EDIT: Had an eye on this since a month or 2, maybe useful to you. Since the seller is from Chennai you can check the item carefully before buying. Price is cheap and still negotiable.
        http://chennai.olx.in/gopro-camera-hero2-2012-excellent-condition-with-all-kit-and-display-attached-iid-555423241

Thanks man, ive made up my mind,
SS motors, CCw/CW combination 10x7 prop, 30A simonk ESC from quadkopters.

This Chinese cam is available everywhere by a name called DVC. from 1700-2500. check your local bazaar where you can find chinese products. Ive never used GO pro but this DVC is awesome for the price, i can rather shed the inbuild Screen to save weight instead of battery.

Thanks alot. will keep everyone posted on build log.

Ashok.P

Edit:
http://www.alibaba.com/product-gs/313686145/DVC_camera_3inch_TFT_LCD_8.html
Exactly the same one but in black. i have one already.

Got my set of ESC motor from quadkopters.com

My setup:
Bumblebee 2812 motor
Quadkopters Simon k ESC 30A
10x7 prop
Avionic servo for Yaw(Will be upgrading to metal gear sooner)
KK 2.1 board
Scratch built frame with ply and balsa dowel from rcbazaar.com
hacked battery mount with Hiller battery tray.
turnigy 2200mah 20c(Will be upgraded to 35c sooner)

the whole setup weighs around 900gms complete.
needs some screws and allan bolts for motors to complete. calibrated the ESC already. all working fine so far.

Ashok.P

Setup complete,

Final specs.
AUW: 1037gms,
Frame: Plywood and Teak wood squares
Bumblebee motor with 10x4.5 prop on 30A ESC with Turnigy 2200mah 20c battery.

Pics and videos soon.
Maiden done with one arm broken and prop, replaced the arm in under an hour.
waiting for replacement prop. Should practice more to get the control right. my piloting skill are still bad for a Tricopter.

Ashok.P

  VIDS VIDS  PICS PICS

plz post them soon Ashok 

unfortunately i am not allowed to upload from my office.
Moorthy sir can help this week with videos(If the maiden went well)

Ashok.P

 

best of luck with re maiden.....

Video.

The copeter was stable enough and with a little yaw,
But i can live with it.
i never imagined it would be this easy with KK board. no major tuning in PID values, simple sub trim in TX solved most of drift problems.
Im getting around 4 mins on a 2200mah 2s 20c battery.

Ashok.P

Super Ashok.. i am coming this Sunday.

nice ashok ......

what board are you using

Thanks Johnny,
Its a kk 2.1

Actually bought it to use it as a flight stabilizer for my nitro plane and found that kk2.1 does not support fixed wing stabilization, that option is missing in kk 2.1. got a little interest in tricopter and built it and later found it was a lot of fun.

Ashok.P

Ashok

 

 

Good one V2 eagle .... : thumpsup :

Sir it would be of help if you could post the specs ..
Arm lengths
Motors used
Props used
AUW
Thanks and Regards ..

Ashok if you post a small guide about how you used to the 10x4.5 props on bumble bee motor it would be great help for me.

These motors are awesome but due to motor mount not many users prefer to use them.

Are you only getting 4 mins of flight time? Because it should be at-least 7-8mins on a full 2200mah lipo and more unless something is wrong.
And are you going to mount the dvc camera mentioned earlier?

My setup is around 875gms with battery and this should be the reason for poor flight timings, but i like the speed and swiftness of this copter and i have no idea to change it to aluminium by now.

Here are my specs

Center plate 20CM dia with holes drilled at 120 degree, spacing 10cm between holes.
arms made of 10mm Teak wood square rods of 40CM in length drilled as per the diagram
use fevicol on all joints for strength, the tail should be bolted with two bolts and the other two arms should have just 1 bolts to allow folding.

Motor mount for bumble bee motor is modified GWS slowstick mount from hobbysea.com

Motor
bumblebee motor from quadkopters.com
http://www.quadkopters.com/product/st2812-brushless-motor-930kv-bumblebee/

ESC:
http://www.quadkopters.com/product/simonk-esc-30a/

Prop:Reamed with a scissor(dont use drill bit) use a scissor and ream it slowly for a snug fit. the props are strong that a complete ream of the inner lugs will not render them weak.
http://www.quadkopters.com/product/sf-propeller-104-5-sf104-5-green/

FC:
KK 2.1  and load the tricopter layout and leave the default PID values as is. change the self stability setting gain to 200 and limit to 30

Battery mount is a modified Hiller battery mount from rcbazaar.com with welcros to strap them.

I think this is enough of info for now as there are lot of build logs available for this tricopter in youtube and flitetest.com

Edit:
Buy 3 nos smiley balls and mount them on the landing gear to save them from any crash, mine crashed once from 5 feet height and broke only one arm. its worth the investment i would say.
Ashok.P

Whats the motor to motor distance?

I am very soon planning to release AnyCopter hub and easy to make copter frame parts in my webstore. I am not able to get a good idea for yaw mount for tri copter.

The motor to motor distance should be around 60cms (Calculated and Measured) give or take a few cms
The yaw mount is the same as David's method with two steering mount but the servo is attached to the bottom of the Arm in the perpendicular axis and a spring steel wire running between them.(Similar to older type dual aileron servos method) ill post a pic tomorrow for sure.

Ashok.P

Pics attached:
My yaw mechanism will look similar to this except these are downloaded from net

The pic for the yaw mechanism of your tricopter attached that you asked for.. 

Thanks a lot for this suggestion...

This really works very well

Johnywalker, how did you get the tilt mechanism, the white hinge like mechanism for tilting the motor

Pradish its called front wheel steering arm

http://hobbyking.com/hobbyking/store/__8432__Front_Wheel_Steering_Arm_Mount_Set_40mm_5sets_.html

Exactly ,

buy two of these
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=56&products_id=1066

and watch the video here.

you will get the idea.

Ashok.P

Update:
Almost lost my copter as the yaw servo gave way, it was spinning in the middle of flight and no one was warned in the field.
Landed the copter somehow with no damage and found that the avionics servo died. replaced it with hextronik servo and found that the yawing issue is resolved now. its rock solid and holds position good.

Ashok.P

That's a good update Ashok. I am planning to buy Avionics metal gear servo for my tri build. Is Avionics not reliable. Where do you get the hextronic one?

i got mine from the hobbyshop.in long time back and they are now non-functional.
emax metal gear servo is available from ebay.in. try it.
Avionics fails for no reason.!!!!!!!!

Ashok.P

Ashok, i was deciding on the props to put on tri and wanted to check if bigger prop 10' one is good. Also on prop rotation, should all the prop be CW or one CW and one arm and tail CCW

One more question, what is the servo specification - Digitial or Analog?
I found one selling emax servos - http://stores.ebay.in/Indian-Hobby-Shop/Servo-/_i.html?_fsub=5010805013&_sid=1125855133&_trksid=p4634.c0.m322

Metal gear servos are better suited for tail servo in tricopters, 9gm nylon ones would fail eventually. Also go for a bigger servo, somewhere between 15-25gm servos, would be much better.

And digital servo are better in case of kk2 because it eliminates lot of jitter usually found with analog servos(its just a theory, hasnt been 100% confirmed yet)

Same as sidewinder except that you can go for a 9gms metal gear servo depending on the type of your yaw mechanism, it should be bind free, slop free and smooth for a long lasting servo.
For props go for recommended pitch and size for the particular motor, mine is recommended with 10x4.5 prop and i went with it.
tricopters are said to be work with all three props cw but the KK layout recommends 2cw and 1 ccw so i went with it and found no issues so far.

Edit: im going to try this servo in a week, let you know the results sooner.
http://www.ebay.in/itm/ES08MA-II-9g-Metal-gear-Analog-Servo-9gm-/201036230040?pt=IN_Toys_Games_School_Stuff&hash=item2eceb16d98

Ashok.P

Thanks SideWinder and Ashok. I will search for a larger digital metal servo. The one on the link is an analogue servo.

I found these two from RCmart.
RCX one, not sure if it is digital
http://www.rcmart.hk/rcx-mg5509-standard-metal-gear-servo-55g-95kg-023sec-p-3854.html

KDS has digital metal servo
http://www.rcmart.hk/kds20044-n290-metal-gear-digital-servo-suitable-for-tail-servo-p-3489.html

are these good options? I couldnt find any Indian store selling digital metal servos

The second servo is better, first one is too big with respect to intended use and altho they have mentioned suitable for tail servo, they are talking with reference to helis not rotors but doesnt matter much. Analog/digital too doesnt matter as much because you can go with a analog too if that's what is available locally. Just make sure its metal gear.

You can take a look at this from rcbazaar but its costly
http://www.rcbazaar.com/products/801-avionic-25g-metal-gear-digital-servo-av9650-500-heli-cyclic-servo.aspx

Thanks SideWinder, I was not going to RC Bazzar as Avionic failed with Ashok's copter. Have you been using Avionic servos
?

There are many factors that can lead to servo failure, so cant guess how did it fail. Everyone has their own experience and then their own opinion. I havent ever used Avionic servo so cant comment on them altho can comment on the 9gm turnigy or clone servos and they are very easy to damage because of poor nylon gears.

I would say go with your gut feeling!

My another Avionics servo(elevator servo on my 3ch glider) failed today.
this was the last one i had in this brand so choose to give it a try on breakup.
found that both servos has no damage on circuit and gears but the motor seems jammed and no more rotating and heat up when connected to RX.
the heat is now proportional to stick movement!!!!
switched it with my tg9 servo and all is happy.(i have 2 hxt900 on my flying wing and they still lives till today in spite of all the crashes)
planning to buy a lot of tower pro from HK for my next build.

Ashok.P

This copter was crashed due to a poor ESC problem and received a replacement from Satya sir today.
also ordered some Fiberglass centerboards with them. should say the difference in weight,
my previous ones are plywood and weighs 150gms, this ones weighs just 49gms.!!!
also the ESC feels sleek and and great. having a exam by 15th and will start and update the status with a video later. planning for a Hextronik motor now.

Ashok.P

Replaced everything in this Tricopter,

DT750 motors, Emax 20A esc, Standard corona metal gear servo,
aluminium square tube, David Windestal style center plate, 12x4 props,

I must admit that the copter turned a little heavy, the arms are short that the KK 2.1.5 oscillates a little during decend. but damn smooth to fly even in heavy wind. Tuning and bettering this copter on the way, put my wing cam onboard and took a video of the surrounding, not bad at all,
around 6 mins for 2200mah battery.

Adding the video here, more to come, real FPV on the way!!!!
https://www.facebook.com/video.php?v=1519344004983426&set=vb.1430630040521490&type=2&theater

Ashok.P