Tri My Tricopter Build by Keith...

[Keith]

Well I'm off a running to give this Tricopter a go..

I got all the bits and pieces at HobbyKing except for the odd nuts and bolts and things I already had..

Here is most of the things I ordered.. Ordered two lots of props, 9x4.7 and 10x4.7 but forgot to show them...






From all the builds I have read about most say the hardest part is making a swivel joint for the rear motor. It controls the rudder or yaw. So I thought I would start with that..

I didn't find it that hard actually. First I got main the blade grips from a old 450 head I had. I then slid a piece of plastic tube from a water sprinkler system over the feathering shaft. Then with a couple of washers I was able to tighten the bolt in the other end to hold it all together. I gave it a good coating of five minute epoxy and slid it into the carbon tube. Even though it is square tube it has a round centre approx 8mm..





Now I had to mount the servo that would control the rudder. I cut two pieces of aluminum angle and pop-riveted them together. I then cut out two slots. One for the servo and the other two fit over the boom..






I fitted the servo to the mount and put them on the boom. I used epoxy to hold the mount firm. I then made up the linkage and fitted it to the motor mount swivel..





I got some flat strip aluminum and cut out the actual motor mount. I took the mount off the motor and had to drill out bigger holes for the nuts and bolts I had. I then mounted this to the aluminum mount..





I attached the motor mount to swivel assembly (blade grip) and re-fitted the motor.



I connected it up to a servo tester and it works a treat..

Here's a view from underneath..



So that's that part finished. I started on the platform next. I found some Plexiglas I had laying around and decided to use that. I thought the best way was to make two equilateral triangles and sandwich the tube between them. I made two smaller ones first so I could get the sixty degrees needed. I cut the shapes out and used a grinding wheel to get the angle correct. I kept rotating one on top of the other until all sides matched. I knew I had it spot on then. I just transferred the angles to make the larger base plates..



I then cut them out and finished them on a rotary sander. I aimed for around 200mm sides but near enough is good enough. As long as all sides are equal the angles will be right. Each boom must be 120 degrees to have it all balanced. So 60 degrees + 120 degrees = 180. Also you will be using the helicopter 120 programmed setting on your Tx..



I sticky taped the two pieces together and marked them out for drilling the bolt holes that will hold it all together. And thats as far as I've got. Not bad for one day. I'll be back at it tomorrow and will keep you updated as I go..








Leave comments and any questions and we will do our best to answer them.

 

[Tony]

Very nice Keith. If you keep posting like this, I will combine all of your posts and put a copy in the article section. Great writeup, and I love the swivel, simple and it works!

 

[Whirlybird]

Awesome job Keith Should be a great flying machine!!!

When will you start selling the kits??????

 

[Jolly-Swagman]

Your off to an Awesome start Keith , I like the Swivel mount for Yaw Motor, and servo mount I was thinking that you would do something like that, as that's how I would have done it. Well Done look forward to seeing more soon.

 

[Lee]

Looks Good Keith, I ordered the 450 blade grips to do a similar thing as you. I'll try and make mine slightly different to avoid copyright LOL

 

[Keith]

Thanks for the encouragement guys...

I'm taking orders now Frabk, how many shall I put you down for?

Don't worry about the copyright laws Lee, as long as you pay the royalties it will be fine....

 

[Whirlybird]

With 2 you get Eggroll . . . right?

 

[Keith]

And ketchup...

 

[Keith]

Did a bit more today guys...
Had a doctors appointment this morning so could only manage a few hours this arvo.
I started by epoxying short lengths of 8mm dowel into the carbon tube. Just a bit longer than the motor mounting plates. I didn't want to crush the tube when I tighten them down. I then drilled 3mm holes through them and fitted the mounts.



So thats all the mounts ready for the motors. It will look something like this when it is folded when not in use. May not turn out quite as compact as this when all the electronics are fitted...



This is how the base plate will look. I also put dowel in these ends.There will be another base plate on this side...





And thats about it for today. I started soldering the connectors to the motors and ESC's and took all the gyros apart and filled them with hot glue. I then hooked each gyro up to a servo and twisted them around to make sure they all worked.

I can finish off the connectors tomorrow and then I will be waiting for the nuts and bolts to assemble it. I ordered them last Friday locally and got an email today saying they had just posted them (5 days). Will not be using them again. So I should get them by Friday...

 

[Paulster2]

Very kewl Keith. Looking forward to seeing how big this thing turns out. Using the square tubes was a stroke of genius. It is sure making it easy to position things correctly and getting them "squared-up" ... very nice.

 

[Keith]

Thanks Paul... Yeah it's turning out good... Of course I have to tackle the electronics yet...Fingers crossed...

 

[Jolly-Swagman]

Coming along awesomely Keith .nice work mate , look forward to seeing more soon1

 

[Keith]

And so we continue....

Rather than squeeze everything together I decided to put another level on. I could then mount all the gyro's here and make some sort of dampening to protect them from vibration.



This is what I had in mind but I made a few changes along the way...



Right, time to start assembling this thing. I used countersunk screws so I would have nice flat platforms to mount things.



I cut out pieces of aluminum angle and used double sided tape to mount them to the platform. I then stuck the gyro's to the angle with the double sided tape. I got the grommets from an old CD-Rom I had taken apart. They are a really soft silicone and should work well to cut down vibration...



The three gyro gain wires need to be spliced together so they can be all set the same. I drilled a hole and fed them through the platform out of the way...




I had some springs lying around so with a bit of tubing I rigged up a suspension system for the platform...



I wanted to mount the ESC's on the platform but it would have stopped being able to fold the booms. So I attached them to the booms and extended the battery wires...



I cut the wires to the correct length and joined them all into a battery connector. Now comes the interesting bit, connecting all the electronics...



And here it is with the motors mounted and the electrics fitted. The booms are 500mm each or rather the motor spindles are 500mm from the center. I went for this size as I can always cut it down if needed...



Once/if I get the electronics working I then need to make some sort of mount to hold the battery/s. Need some sort of undercarriage and then it's lift-off.....

 

[Lee]

Wow Keith, looking real nice. Its a much more professional job than mine will be. I have no work shop or tools to use. Just a saw, so i'll be making my frame from plywood

 

[Keith]

Thanks Lee.... I've always been a bit of a hoarder and can usually find something I need if I look long enough. I'm lucky enough to have a big garage and built this workshop in one corner. It would be a lot more functional if I could keep it clean and tidy.
I'm having fun with theses electrics... It's taking a while to get my head around it. I've managed to get the gyros and ESC powered up together with a BEC to start it. The initialization takes for ever. It's beeping and playing tunes for ages, then one motor will start. Another couple of minutes another motor will start. And that was it for a while. Anyway I got all 3 motors running now but one will not shut down at low throttle. I have to go through the setup of the Tx and gyros, and get into the ESC's. Once I understand how each function I should start getting somewhere.

 

[Tony]

Should be as simple as resetting the ESC's. Power on your Tx and put the throttle stick all the way up, then plug in the tri-copter. When you hear 2 beeps (I think), lower the throttle stick and they should all be reset.

Build looks great man, can't wait to see the maiden of this thing.

 

[Keith]

I wish it was that easy Tony... You can't power the tricopter straight up... I'm not sure of the reason but the gyros will not power up until the ESC's tell them to and visa versa... So I use a separate battery to turn the gyros on then plug the main battery in, the ESC's fire up then I disconnect the small battery... It's hard to tell what's beeping, ESC, gyro...? plus you got 3 of each and I think they are all beeping at different times... I might do a short vid tomorrow and entertain you all...

 

[Tony]

You could always bypass the gyro just to get the ESC setup. If you don't set the esc up, one motor will want to raise more than another, making it hard to fly. That is unless you have spliced all the wires together lol.

And I have never heard of anyone having to use seperate batteries to get them to power up. I guess this is another nail in the coffin for the 401B in my book. Hope you get it working correctly soon.

 

[Lee]

I bought the Bec to do the "Jumpstart" but i've also seen where you just put a switch between the battery and the ESC's Plug in the battery Gyros initialize then switch on the ESC's. My knowledge is very limited i'm just following what other people have told me works

 

[Keith]

We have been looking at the same articles Lee... I use the BEC, but have also seen that jumper switch... The BEC works fine and long as throttle is WOT... I'm just not sure if you leave it connected until everything is initialized or unplug it as soon as ESC's switch on...?
What I can't work out is you connect all gain wires from the three gyros and plug them into channel 3. Well channel is the throttle channel and as soon as you rev the motors up the gyros switch from rate to HH mode. Must have to reassign channel 3, but then I can't see how the throttle will work... My head hurts....