T-Copter build

[Leigh]

G';day,

I have been slowly collecting parts for a T-copter (simplecopter.com) - Matt Hall has an awesome design for very little $$ and it runs on the very popular and stable KK2.0 with 1.6 firmware.  I built a custom yaw mechanism for it.  Matt has some awesome build and flight videos on Youtube and, of course, I highly recommend you grab one of his frames - they';re an awesome design.

Here';s my first attempt at anything like this: 5mm plywood; 18mm booms; 312mm from motors to center of mass / middle of the KK2.0 board; AUW 900g with battery:



Results of my yaw mechanism tinkering:

T-Copter servo yaw mechanism

It was inspired by EnigmaSoar';s design, although I think the original is much more elegant than my first hack attempt!

After receiving my HobbyKing usbASP in the post last week, I decided to upgrade to the latest KK2.0 1.6 firmware as my board was shipped with 1.2 as standard.  First problem: the HK usbASP seems to have been shipped without any firmware on it - so any machine I connect it to complains that the usb device is not recognised - regardless of OS.   

Not wanting to give up that easily, I remembered that I had used my Arduino Uno as an ISP for an AtTiny in a previous project, so I decided to try and see if LazyZero';s kkMulticopter Flashtool could use it as one too - and, after a bit of mucking around, it worked :)

Click on the images for larger pictures and more details on the pinouts.

The KK2.0 ISP pinout reference I used was:



The mess of cables looked like this:



The results speak for themselves:



Hopefully this will help someone along the way.

I did some tinkering in the shed today and, after soldering an XT60 plug onto my power wiring harness, I decided to mount the yaw mechanism and attach the props which I carefully balanced a week or so ago.  The SunnySky 980kv motors I got from eBay were perfectly balanced, so what could go wrong?   

First thing that went wrong was that the servo was clearly in a "reverse" position as far as the default settings in the firmware are concerned - so as soon as any throttle was applied, she violently span around like a top.  After a bit of fiddling, I found the mixer settings to allow me to effectively reverse the servo (the radio settings were fine, according to the receiver test).

Next thing that went wrong: I misconfigured the elevator values on the aileron motors, but left the default value on the tail motor.  Next blip of the throttle launched the tricopter head-first into my car';s front bumper (from my garage).  Hmm, time to move outside onto the lawn!    

Finally got the mixes right (after firmly holding the tricopter down and testing each control surface *properly* (  ) and got it to hover at about 6" off the ground on my lawn - AWESOME!   

I headed off to the park to walk the dog with my wife, Bixler and Tricopter loaded into the back of the car so I could have a fly on the way home (after taking my wife shopping, of course).

We got to the field at around 3.30pm and, after a 5 minute relaxing tear around the skies with my Bix, I popped the tri onto the grass and had a bit of a go at some reasonable height hovering.  I forgot to bring my video camera, so no youtube moments to share unfortunately, but I did manage to get two fantastic 5 minute flights out of my two 2200mAh 3S nanotech';s that were charged up - happy days!  Stabilisation was a bit jittery as the ESC';s are not yet flashed to SimonK - that';s happening tomorrow morning over brunch - sadly the rain is back in Belfast so I won';t be able to fly it again until next weekend - where hopefully the sun will be shining again for our club';s heli day fly-in :-)

Anyway, glad I have found a great forum with lots of people sharing their experience - looking forward to sharing more of mine and perhaps meeting a few fellow multirotor nuts at some point!

Cheers

Leigh
Aussie on the loose in Belfast, NI.

[Gaza07]

Hi hart and welcome to the forum thats a cracking first post you have made there, I look forward to seeing more of your Tcopter build 

[guest325]

Great first post, hope to get my a4se into gear and get mine back on track!
I like the yaw mechanism very much, looks like you';ve given me a solution to what I';ve been trying to sort out for a while now - I got close to that idea but it wasn';t as elegant (rather crude by comparison).

[Leigh]

Cheers for the welcome and great feedback guys - I met a friend for breakfast this morning and he flashed my ESCs with simonk - took mere seconds!  We then headed up to his airfield and, after re-calibrating the ACC and throttle settings, I took her up again!  I forgot to video the main flight, but after landing I had 38% battery left so I grabbed the camera and took it up for another minute ;-)

Simple T-Copter flight after ESC flashing

[guest325]

Nice to see someone else who flies without the broken L/H stick 
Not many of us about flying mode 1 rotary wing!

[Leigh]

Nice to see someone else who flies without the broken L/H stick 
Not many of us about flying mode 1 rotary wing!

Indeed!  I think there';s maybe two others at my club who fly mode 1 heli - old school Futaba too ;-)  That brings back some memories!

To be honest, I do find mode 2 more natural for my mini v959 quad, but for some reason mode 1 feels better for the tricopter.  And of course I learned to fly planes mode 1 when I was a teenager, so that';ll never change.  My brain is clearly a little odd ;-)

[Leigh]

Some POV flights from my T-Copter at my club';s airfield.  Awesome weather today.  Big thank you to my darling wife of 21 years who put up with me flying on the way to our anniversary dinner!   

T Copter POV flights