Tiltrotors, what are peoples opinions on them?

[Browny_37]

As per the subject title, what are peoples feelings towards a Quadcopter Tiltrotor design?

After seeing the OFM Swift TR260 by Alishamano on Youtube, I was inspired to build my own.

So I slapped a very basic wooden craft together using plywood and hardwood block and ended up with a quad of a 280 size. Slapped some oneshot escs and some 2204 motors on. Nothing was true in dimension.

So two days after starting the build, I had a tiltrotor quad. I plugged it in and everything armed, the flight controller had been setup prior (tilt mechanism working through FC channel)

I armed her up, and punched some throttle in. She shot upwards and into life, i was amazed at how stable it was!
A little numb on the controls (I managed to get out of control trying to stop it from fast rearward flight, narrowly averting hitting the frame on my decking and launching the quad into the tree.)

Needless to say it fell out of the tree minus the props and slight undercarriage damage. 

I spent a day or two playing with the setup and it was getting even better. I think the geometry of the quad itself was letting it down. As it was doing some bizarre punch outs if i didnt feather the thottle/elevator.

Over the past 4-5weeks,. I';ve taken the plunge and started learning CAD and 3D Printing. I';ve produced a MK2 version which has encountered many electronics faults and was over 600grams in weight for a 250/260 sized quad.
I felt this was a little on the heavy side although it didn';t seem to be affected by it in flight, I had the FC at 90 degrees to the frame (changed the orientation through the software) As I think this may have caused a crash on my 4s run.
Whereby the Quad did a diagonal front flip at about 50mph landing on a rear boom and putting it on its top and sliding along the carpark. The frame proved durable.

So onto Mk2.5, further weight stripping and changing the FC orientation.
Maiden is yet to happen, but I';m hoping I will have video of it working tomorrow.

Sorry for babbling on a little, I shall include some pics of the build soon.

[Browny_37]

Heres a pic of the progress so far.

[hoverfly]

Interesting .....very interesting. watching this space..

[Browny_37]

Had the opportunity to do some tweaking and flying on Sunday.

Here';s a video of one of the test flights

https://www.youtube.com/watch?v=PIkqM16QGAA

Flying via FPV is somewhat strange, having no tilt makes things feel rather odd.

[DarkButterfly]

Had the opportunity to do some tweaking and flying on Sunday.

Here';s a video of one of the test flights

https://www.youtube.com/watch?v=PIkqM16QGAA

Flying via FPV is somewhat strange, having no tilt makes things feel rather odd.

Could you not add a custom mix in your radio, so the quad tilts forward a bit, then the rest is done with the tilt rotors, that way FPV won';t feel quite so strange and the FC will be getting the input it expects.

Good design, well done

[Jake Bullit]

Nice work,subbed :)

[hoverfly]

Test flight looks really good, are you using a mix to control rotor tilt?

[Soler]

I heard report that with this configuration its easy to get spin out on corner due to the back props seeing the dirty air from the front ones.  Have you found this?

[annikk.exe]

You can tell Cleanflight that the motors have been tilted, this might improve the handling, particularly for self-levelling mode.

Code Select Expand

set align_board_pitch = 10

(Hopefully that';s the right command... if not maybe someone will correct me)

[Browny_37]

Hey all, thanks for the comments.

I';m using Openpilot on CC3D Evo board, theres a tx mix to allow for rotor tilt. The mix for the tilt runs through the FC board. The FC is mapped against the elevator channel.

As I';m a Spektrum user, the only way to use CPPM for oneshot capabilities is to use two Satellite receivers, or I would have had to use a PWM to CPPM adaptor (more weight and wiring). I';ve had orange receivers (full range versions) and had an abundance of problems with them in cheaper models. Lockouts and pauses to full on brownouts. So I didn';t want to be riddled with problems..

Anyway not here to start a mass debate on Spektrum Tx';s (each to there own I say)

Openpilot allows you to run what ever angle you wish to choose in attitude mode (where my current experiences revolve around with regards to the tiltrotor)
Although its currently set to 0 degrees, the FC still allows the quad to pitch forward at high speed.

Although I am wondering if the prop wash/elevator differential is taking over to try and make the quad pitch forward. 5 x 3 props make it do a weird thing where it actually starts to climb and doesn';t react to pushing the pitch further forward. I suspect there';s a lack of lift at the rear props. Bang a set of Bull nose 5 x 4.5" props on there and it tracks straight and goes like it does in the video.

As for sliding out at the corners, it does tend to rev its nuts off trying to pull out of a turn on the flat. But it doesn';t feel out of control where your needing to put tons of input in to keep in control. Offset motor mounts are the next thing to design and produce for experimentation.

I';m finding this obsession with racers is taking over at the moment, and I';m currently gearing up for an FPV racing event fast approaching. So my concentration has revolved around readying for that and spending time with the missus and working.

The tiltrotor has seen me up at 3am still for the last couple of weeks trying to work along side a coder to produce a working firmware for CC3D, and has burnt me out. Unfortunately they don';t use CC3D boards themselves, and being in another country makes it that bit harder to try help them develop a working firmware for cc3d controllers. I';ve learnt I need to put it on the back burner so its not had as much attention over the past week.
I do have a Naze32 Acroflight board to try out (soldering it now as a matter of fact) I have some firmware geared at Tiltrotors. I';ve never used cleanflight before, so im going to be scouting painless360';s youtube videos again for info on setup.

But I am looking forward to demonstrating it at the FPV racing event, and get some true thoughts and opinions if its worth seeing if it belongs in the FPV world. Maybe if i get time tomorrow and I can get the 3D Printer to play ball i';ll knock some offset motor mounts up to try.

I';ll be honest there';s not really been a true amount of maths in the building of this project. Its been a suck it and see sort of thing, based on my own beliefs. There';s been simple maths to build a frame that exhibits symmetrical  properties.

Elsewhere I';ve had people ask the motor angle and a vast of other questions i';ve not been able to answer yet. As I';ve just played with the settings.

[Browny_37]

You can tell Cleanflight that the motors have been tilted, this might improve the handling, particularly for self-levelling mode.

Code Select Expand

set align_board_pitch = 10

(Hopefully that';s the right command... if not maybe someone will correct me)

Sorry, I didn';t notice this comment last time. Unfortunately I don';t use the Naze32 on the Tiltrotor atm.
The motors are variable depending on elevator input. So a static pitch command wouldn';t be beneficial.

It';s still on the CC3D board atm, I';ve not been around due to health problems. And any time i';ve had, I';ve spent on swapping a racer and my 350 video footage quad over to Betaflight/Naze32.


The tiltrotor got an update recently to offset motor mounts, in relation to the booms. Basically to try lowering the front props and raising the rears whilst on elevator commands as to try and give the rear props some cleaner air to work with.

Managed to get 1/2 an hour to play with the tiltrotor in the garden. Footage wasn';t recorded at a very good angle. So I do apologize, its best viewed on a larger screen like a laptop.

https://www.youtube.com/watch?v=_HopI7hB254



Just need some good weather now to try it out on FPV

[shazzy]

would love to see your tilting mechanism!

[yorkiejeff]

love it bud, but i have a question to ask and please take it as ignorance and not a ctritic. why a tilt rotor? surely quads take off vertical and fly well. this isnt me having a go, more me wanting to learn more. does look  lot of fun to fly though