Original tricopter body modified for V-tail!

[Kogashuko]

So after my tri issues with stability and such I tried a PVC Vtail. Looked cool but was way too heavy or at least I think. There might have also been other issues. My issue with it was that it was big, heavy, and hard to transport. So I went back to the tricopter frame and changed it!

 

[Toddy]

Interesting! How far have you gotten on your build? I would be thinking that you have had it out, trimmed it up and onto version two by now ,no? If not why not. Would love to hear your conclusions on the vtail frame.

 

[Cyberdactyl]

Oh my. That's an intriguing alternate to David W's plates. So much so, I'm tempted to order another set of the G10 cuts.

If square wood dowel was used, I'm thinking little pieces of bamboo skewer could be split and glued to the outside edge a few centimeters down on the outside, and a taught rubber band (green), or possibly a small zip tie to hold the two booms tight against the lower screw stops.

 

[Kogashuko]

Getting there. I only work on it about an hour at a time because I have other commitments. I need to come up with a good solution for the battery tray. I dont have the equipment or tools to cut the wood like they did. So, I might just mount the gopro to the black tip on the top and the battery between the booms. Yet to be determined...

 

[Kogashuko]

Oh yeh and the back two props are going to be replaced...

 

[Mustang7302]

What size prop are you running on the rear motors? Are they offset at an angel? What is the distance between motors?

 

[Kogashuko]

Props are 9x4.7 front and back. I might go larger with the front if I can get larger counter rotating ones. Hobbyking seems to be out.

As for angle, I am right at 45deg and the distance between the rear motors is just enough to the propellers dont hit.

 

[Kogashuko]

Update


Will probably go up tomorrow after work! will let everyone know.

 

[Kogashuko]

Ok so I tried to launch tonight.

All of the PIDs are stock and the only thing I have not calibrated are the ESCs in the mission planner. Considering I actually got off the ground with the try makes me think it isnt necessary. Every video and guide I have seen the things will at least launch and be slightly unstable.

This thing wants to close one of the front arms which I can not even move when it is not flying. Weird since the ones on the flight test video seemed so stable.

When I give the thing throttle it bobbles around. I have full GPS lock and all. I tried cranking the throttle at full and it just bobbled around rapidly until one of the rear right propellers started smacking the ground and unscrewed itself.

This is insane. Followed every direction to the T and this thing still will not make it off the ground.

Beginning to think this whole custom multirotor thing is a scam.

 

[Kogashuko]

Here is a video of an almost identical design on its first flight. No prop balancing or anything else. It takes off and does not blunder around...

 

[Kogashuko]

So.... after screwing with the PIDs and calibrating the ESCs I tried again only inside. This is a small room and the thing looked like it was going to take flight. Since the thing sounds like a weed eater I quickly turned it off because the room is way too small and my wife is sleeping in the next room over.

Time to stop drinking saki and go to bed. Tomorrow looks promising.

Also, any tips as to anything to use between the props and the motor body like on the flitetest videos to cut down on the friction? I dont have one of those kits or a cnc machine. Should I just get another set of self locking bolts? Thanks.

 

[Cyberdactyl]

Also, any tips as to anything to use between the props and the motor body like on the flitetest videos to cut down on the friction? I dont have one of those kits or a cnc machine. Should I just get another set of self locking bolts? Thanks.

I'm not sure what you mean in "cut down on the friction".

I believe you mean you want more friction between the nuts clamping the prop.

But I have to be honest, I see no need for the Flitetest recommended wood washer for the DT750s. I've never used them and my props don't slip. All I use is a regular nut on the bottom, tight to where the threads stop, then a regular washer, then the prop, then another washer, and a locknut on top. You can forgo a locknut IF you use Loctite (blue) on the top nut OR check the regular top nuts before each flight (are the props slipping).

 

[Tritium]

I just received some 4mm collet prop adapters from Value Hobby. I cut the shafts off at the thread bottoms on my DT4023-850's.

The collet adapters sit down directly on the bell and do not "pull" on the shaft at all when tightened. Very little chance of bending a shaft in a crash also since the shaft is completely captive in the prop adapter.

Thurmond

 

[Kogashuko]

Tried to launch the thing again tonight with more issues. The thing starts going up and immediately topples forward over on itself and snaps another set of rear props. This is the same issue my PVC build had and I thought for sure it was too heavy. This build was not too heavy and did the same thing. The gyros are calibrated along with the ESCs. The only thing not calibrated is the accelerometer but the damn thing isnt even moving yet when it has these crashes. I dont see why it would flip forward because it has a gyro that should level the thing out not crash it! What purpose are the gyros and GPS if they arnt going to do this.

I am very very tempted to just nix the whole flite test build and go with a normal quad.

 

[Cyberdactyl]

Don't panic.

Unless you have a bad KK2, I'm sure it's a problem that can be solved. And that can be easily checked by going to the MENU and then to SENSOR TEST. If you have OK all the way down for all the gyros and ACC. . .it CAN be figured out.

 

[Kogashuko]

I think I have it. From doing some research it does not seem that the megapirate Vframe option takes into account for canted rear motors. So, I dont want to go to multiwii and I will just move the two rear booms further apart and remove the angle brackets. At least that is until they update the firmware. Not a big deal but I think a quad is easier to learn on anyway. I was flying a mini syma quad today and it was a lot of fun. However, almost impossible to tell direction. I am better off getting my gear together including RX and TX kit plus invest in a FPV kit and then start messing with other stuff.

So all in all the board was doing its job. It kept seeing the rear motors spinning faster and not getting lift. It then tried to compensate on the front two motors but got confused. Finally, the whole thing flipped over because the rear motors thought they needed to go faster and faster and the front motors kept going slower at the rates of them all being even.

I also took the time to invest in a folding quadcopter frame. $50 did not seem bad for a secondary that I will probably build up as soon as I get this one straight. So, if this setup does not work I can transfer my parts over in time for my annual beach trip and get some cool video!

 

[Cyberdactyl]

Opps, sorry, I thought you had a KK2

 

[Kogashuko]

Got a new set of props tonight. I kicked out the two rear booms and have the motors flat for now. I went to fly tonight and held the thing and felt very even lift as I adjusted the throttle. The only issue I have is the props still flying off and the left front arm trying to fold on launch. I am going to work on making the thing more rigid tomorrow. Seems like it is going well so far.

Hopefully to have some video soon. I have a KK2 board and another crius board inbound. I really like this hobby so far and foresee doing more of these.

 

[Kogashuko]

Ok here is a photo of my quad.



Did a short flight with it today. I am still having an issue but overall better. My new issue is a power issue. I noticed this ever since I added the forth motor that things were sluggish. I have to put full throttle on the quad to get it to lift. I am running a 30c 2800 mha battery. Is it too small and should I be going for a higher C???