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#1 foam and tape Sep 15, 2011 05:43 PM

QTR Quad Tilt Rotor
 
8 Attachment(s)
Just been kicking around the idea of this after seeing the X-19 and hearing things that Boeing is taking on a new approach to the thing.:rolleyes: Although the X-19 never made a full transition, i'm pretty confident that it would have flown just fine conventionally. I'm currently just spinning off the idea/concept of the X-19 and concept drawings piecing together my latest project (fail).

So far the air frame prototype is complete, its currently using the HK KK board for control which holds it in an amazingly stable hover :cool: the only thing that needs some improvement is yaw control but I can live with it.

flying however, is a totally different problem, since the model is soo large the gains are set fairly high on the KK board so in conventional forward flight the board is constantly fighting any changes of the airplanes condition :ex speed up the two front motors to pitch up dosent work soo well while its in forward flight mode. The real problems come with the roll channel. since roll in hover mode comes from Ch1 or ail on your receiver, forward flight mode makes the plane act funny since rolling it in airplane mode simultaneously speeds up one sides motors acting like aileron/rudd mix (sounds all good right?) But it doesn't work as the gains are WAY to high in FF flight that its almost impossible to turn without rolling it way over and just jamming down on the sticks.

^in short its just a big mess that just does not work, also yaw control is a PITA.

After seeing Leadfeather's thread with his awesome Wiimotion plus controller with the arduino and seeing just how well it works in different flight modes EX: being able to turn off certain functions in different flight modes it seems more logical to go with one of those.

Currently i'm assembling it and hope to have it done soon, I'll try flying it in quad X mode first, so I can "learn" how to upload the code to it. then figure out what kind of code would I need to get it to work

Basically I have 3 flight modes:

1: hover (quad mode)
gyro gains active
flight controls active (or not) I really don't care
switch off

2:transition
gyro gains active for 5 seconds, it would be ideal for the values to be turned down to 0% in a slow motion function. After the gains are set to zero the motors only respond to ch3 or throttle
flight controls active
switch on

3: forward flight (airplane mode)
gyro gains off (motors only respond to throttle only)
flight controls active
switch on

4: transition back to HOV
gyro gains transition from 0% to 100% in a 5 second duration
flight controls active
switch off

^^^^ is this possible to do with the wii arduino thing??:confused:

anyway here are some pictures for now :popcorn:

video will follow of it in Hover mode if the wind ever calms down. :rolleyes:

#2 RCvertt Sep 16, 2011 01:54 AM

Your build looks really good. Nice and light, unlike my attempt which was a beast at 1800 grams.

Quote:

Originally Posted by foam and tape (Post 19328107)
^^^^ is this possible to do with the wii arduino thing??:confused:...

It's all doable. The tweaks you need shouldn't pose a problem.


Yaw tends to suck if you're using regular quad copter torque. For improved yaw you can move the left and right side motors in opposite directions. You can move all four motors or just two will probably be good enough.

#3 leadfeather Sep 18, 2011 08:34 AM

F&T, very cool project! I was thinking about doing a quad VTOL too.

Here are some ideas and advice based on my experience with the F-35

1) Gyros on motors and control surfaces "on" at all times except control surfaces in hover ( they just sit there and flutter in hover). I could fly my F-35 very tail heavy in forward flight with gyros, unstable without.

2) To simplify, you may only need to tilt the front motors. With dual tilting front motors you'll have yaw control in hover and and be able too do all the transition stuff and enhance roll in forward flight. The rear motors shout down or idle in forward flight.

3) A lot of the tweaks to the F-35 code would apply to this ship. I think the easiest approach may be to modify the F-35 code to accommodate the quad rotors.

Looking forward to your success. I'd be glad to help as much as I can, but programming wise, cass3825 is the master.

#4 v22chap Sep 18, 2011 08:49 AM

Cool idea F&T hope all goes well in your flying :)

#5 cass3825 Sep 18, 2011 09:49 AM

I like where this build is going! We're very close to releasing the V1.8 VTOL code, which would require minimal changes for your ship. I'll be sure to post a link here as soon as it's available for download.

#6 Rocketman1092 Sep 24, 2011 02:44 PM

1 Attachment(s)
Hey foam and tape,

I'm super happy to see that you're working on this project, as I've been working on nearly the same thing as an FPV platform. I was going to try a KKmulticopter board, but I guess I'll wait and see what works for you. Please update the thread as your experiments progress!

#7 cass3825 Sep 24, 2011 06:28 PM

Here's a link to the MultiWii VTOL code with definitions for tricopters. It would make a great start for a quad VTOL aircraft! http://www.rcgroups.com/forums/member.php?u=56274

#8 foam and tape Sep 24, 2011 08:53 PM

sorry it took soooooo long to get back to this project! :p I've been crazy busy with college stuff and work.:(

RCvertt, NICE!! I'm glad someone else attempted this thing too, what happened to it, did you ever try transitioning it?

Leadfeather, thanks man, its good to have input from one of the brightest members around here!:)

V22chap, thanks :D lets see if it crashes or burns!

Rocketman1092, i'll keep you updated, if I ever get more time to build this stupid thing, i'm glad there's plenty of interest in this type of setup.

Cass3825, thanks for all the info with the coding stuff, its the only part of this project I can't figure out how to do. I'm glad some one here has the expertise in this field. :cool:

#9 RCvertt Sep 25, 2011 03:37 AM

Quote:

Originally Posted by foam and tape (Post 19412370)
...RCvertt, NICE!! I'm glad someone else attempted this thing too, what happened to it, did you ever try transitioning it?...

Never transitioned it. At 1200 grams I thought it was still to heavy to try and the more stable MultiWii didn't exist yet. I've also recently joined the rest of the world in discovering blue foam which is a lot lighter and stronger than the ice cooler stuff that chuck glider was made out of.

#10 v22chap Sep 25, 2011 10:17 AM

F& T also glad to hear the word College in your post above ... glad it is all working out for you and I wish you the best in that area too .
I see no reason that it will not transition very well ... much like leads 35 if cass can get the code changed for your 4 prop bird ... and from what I have seen him do so far ... that is not a problem :)

#11 foam and tape Oct 07, 2011 08:18 PM

2 Attachment(s)
Well after some super frustrating time I *think* I got the MWC thing working OK, flight performance needs some tweaking as too much yaw drives the board crazy :confused:. The next real hurdle is the code to make the arduino behave as it should. Can some one PLEASE help with that part as I have abosolutely NO idea what to do next...:p I wired mine up like this:

Any help appreciated (and needed)! :D

#12 cass3825 Oct 07, 2011 09:38 PM

There are some excellent PID tuning recommendations here that should help!

#13 RCvertt Oct 07, 2011 10:12 PM

Quote:

Originally Posted by foam and tape (Post 19533061)
Well after some super frustrating time I *think* I got the MWC thing working OK, flight performance needs some tweaking as too much yaw drives the board crazy :confused:. The next real hurdle is the code to make the arduino behave as it should. Can some one PLEASE help with that part as I have abosolutely NO idea what to do next...:p I wired mine up like this:

Any help appreciated (and needed)! :D

I'm a little confused on where you are in the build process exactly. Have you actually put your board into a quad frame and tried to fly it yet? Or are you just wiggling the board and looking at the gyro graphs in the configuration program? I recommend putting your board in a simple wood X config quad frame first and solving any yaw problems there first before moving onto to VTOL modifications if you haven't done that already.

Also need to know which version of the MultiWii code you are using. Case and Led can help with (1.8). I can only help with (1.7) questions.

#14 foam and tape Oct 07, 2011 10:21 PM

I'm using 1.7 and yes I've tried flying it in this airframe.:eek: So far the results are good on Pitch/roll, yaw is giving me problems. If I feed alot of yaw control in during flight it seems to hesitate, once I add more it starts to go out of control then looses control on all axis then it crashes:confused: I'll try and get some vid tomorrow. :)

#15 foam and tape Oct 07, 2011 10:22 PM

Quote:

Originally Posted by cass3825 (Post 19533710)
There are some excellent PID tuning recommendations here that should help!

cool, i'll check it out and see if I can get it to hover better.:cool:


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