atomic's thrown together Inverted V-tail (or should that be A tail)

[atomiclama]

Well this all started after I stripped down my little quad with a view to upgrading the motors. When it came to the rebuild
I just couldn';t be a$rsed trying to fit it all back in and include some fpv stuff as well, so I set about looking for an alternative.
Plenty around but all look the same and I was after some thing a bit different and it needed to be cheap and easy to replace once I crashed it.

So started to design in my head what I was after. I had grand ideas about drawing the whole thing up in some CAD package printing it out and cutting it out in GRP but in the end it was all just too much effort. So I scetched it out on a bit of scrap paper rummaged around in my garage for some scraps of wood, 10min later I had a basic frame, now that was much easier. If is dosn';t work then no loss I';ll just strip it down and burn the frame.





3mm ply plates
10mm something arms
120gms for the frame

Ohhh lots of space

Motors and ESC fitted.
https://www.banggood.com/DYS-BE1806-2300KV-Brushless-Motor-Black-Edition-for-Multicopters-p-946416.html
https://www.banggood.com/Emax-Simonk-Series-12A-20A-25A-30A-40A-ESC-For-Quadcopter-QAV-250-p-918126.html



Now to find my Naze32

All fitted out and ready to fly  ::)

Total weight without bat 262g

[Hands0n]

Wood huh?  You';ll have @darrellw shaking you by the hand. 

Pictures. Or it didn';t happen 

[atomiclama]

give me a chance, lunch time then there should be a camera in the lab.  ::)

[guest325]

Excellent - another convert to Woodies  ::)   ::)   ::)   

[flybywire]

Watch out for the splinters tho!

[atomiclama]

OK so what do you woodies use to glue the bits together ?

Currently I';m using some Cyano I found in my box but no idea how strong it';ll be.

[Hands0n]

I just use Wickes regular white wood glue where required, and i';m not in a particular rush.  Otherwise its bolts, nuts and washers if I want demountable. 

[guest325]

OK so what do you woodies use to glue the bits together ?

Currently I';m using some Cyano I found in my box but no idea how strong it';ll be.

Ordinary cyano is ok but it';s a bit too brittle - Gorilla cyano has rubber particals in suspension so is a bit less brittle, I always use it now.

[kilby]

Hobbyking also do a flexible ca

[atomiclama]

Yeah it';s alive and flying well.

I do like Yaw on this thing  ::)

[guest325]

Yeah it';s alive and flying well.
I do like Yaw on this thing  ::)

Excellent!!!
Yes the yaw is rather different to a conventional quad, Tricopters rule for yaw though - shame about having to use a servo though - the only weak link!
Have to wait and see how my tilted motors idea works, if it don';t VTail here we come ::) ::) ::)

[atomiclama]

yeah very snappy, got to tone it down abit as I';m hardly using any range in the sticks.

Hovering at ~25% on the throttle which make decending tricky as it gets close to shutting down and tumbling out of the sky. Need to adjust something just not sure what.

[atomiclama]

Doh !

Just twigged that I';m still running with the X quad mixer in cleanflight  :embarrassed

Still flying well, I';ll have a look into the mixer tables, see what the differnce is.

[atomiclama]

Tough little frame this one.

So far I have flown it full speed into a goal post. Sent it cartwheeling down the field. Dropped it out of the sky from a fair height when a prop fell apart. Landed tail first a few inches deep in the mud, just pushed the motor back into position and carried on. Oh yeah the dog ran off with it between it';s teeth. I think he was getting jealous of me playing with the quad instead of him.

It has some bad wobble in it when disturbed by the wind, but I';m enjoying flying it too much to bother sorting it out.

Almost out of props, the last set look a bit too bent to fly but it still works.

[forest]

thanks interesting thread

[Rustydiver]

That is so cool.
I won';t have a go at building one now.

[Beaver2206]

It has some bad wobble in it when disturbed by the wind, but I';m enjoying flying it too much to bother sorting it out.

And that';s what it is all about!

[guest325]

It has some bad wobble in it when disturbed by the wind, but I';m enjoying flying it too much to bother sorting it out.

I think if you took some of the area of the top and bottom plates out that';s not actually doing anything it would improve it. But as you say why mess when you are enjoying it... mk2 maybe?

[atomiclama]

Oh the thread has come back to life!

Thanks for the comments all.

Bit of an update.

The frame has taken a bit of a battering, all the cyano joints have given way or rather the bonding within the ply has gone, its now held together with a couple of screws, hot melt glue and zip ties. The frame is not as stiff as it was.

The wobble has gone after I made some time to tweak the PIDs, had to up the P gain quite a bit from the default.

Swapped to Gemfan 5x4.5 props that give it a bit more punch.

Got two quirky problems that I';m trying to solve.

http://www.multi-rotor.co.uk/index.php?topic=9378

http://www.multi-rotor.co.uk/index.php?topic=12060


Yeah, MK2 beckons. FPV pod (when I get that sorted) narrower centre section and tilted front motors.

[forest]

cheers for the update

[atomiclama]

Doh !

Just twigged that I';m still running with the X quad mixer in cleanflight  :embarrassed

Having run out of things to twiddle with I thought I see if I could improve things with the mixer, looking through the code to get my head around the mixer table, I found they have done it already 

Atail mixer here we come.

[atomiclama]

Well that was interesting.

configured the mixer to an ATAIL4

didn';t feel right when I powered up and held it, but ah well lets give it a go.

the thing pops a a few feet and sits there going round like spinning wheel on acid 

Need to tweak that mixer the YAW settings are round the wrong way, for me at least.

Onwards and upwards  roundwards

[atomiclama]

Updated to newest version of cleanflight.
Enabled PID =2

Flying like a good un now. Just need to drop the yaw rate as it is now very responsive.

Current setting non default (more for my records): -
4-1-15
mixer CUSTOM
cmix 1 1.000 0.000 1.000 -1.000
cmix 2 1.000 -1.000 -1.000 0.000
cmix 3 1.000 0.000 1.000 1.000
cmix 4 1.000 1.000 -1.000 0.000
cmix 5 0 0 0 0
set looptime = 2500
set emf_avoidance = 1
set mid_rc = 1520
set min_check = 1040
set max_check = 2000
set min_throttle = 1050
set max_throttle = 2000
aux 0 2 0 900 1300
set acc_lpf_factor = 50
set pid_controller = 2
set rc_rate = 100
set roll_pitch_rate = 50
set yaw_rate = 40

[quadfather]

Just need to drop the yaw rate as it is now very responsive.
...
mixer CUSTOM
cmix 1 1.000 0.000 1.000 -1.000
cmix 2 1.000 -1.000 -1.000 0.000
cmix 3 1.000 0.000 1.000 1.000
cmix 4 1.000 1.000 -1.000 0.000
cmix 5 0 0 0 0

I wonder if you should reduce the yaw ratio for the rear motors. Since they are angled they don';t need to run at max yaw.

I never understood why they included V- and A-tail mixes as they are extact copies of the QuadX ratios. 

[atomiclama]

I wonder if you should reduce the yaw ratio for the rear motors. Since they are angled they don';t need to run at max yaw.

I never understood why they included V- and A-tail mixes as they are extact copies of the QuadX ratios. 

I';ve just dropped the yaw_rate down and it is now much more flyable.

The QuadX ratios are different - at least in the cleanflight code I have

static const motorMixer_t mixerQuadX[] = {
    { 1.0f, -1.0f,  1.0f, -1.0f },          // REAR_R
    { 1.0f, -1.0f, -1.0f,  1.0f },          // FRONT_R
    { 1.0f,  1.0f,  1.0f,  1.0f },          // REAR_L
    { 1.0f,  1.0f, -1.0f, -1.0f },          // FRONT_L
};

For my mix (based on the one in the code) the ROLL is controlled by the front motors only and the YAW by the rear motors only.
I did start off with the QuadX mix, it flew but rolls were sloppy, I think the using the rear motors during roll tried to induce some yaw that upset things.

Anyway it felt much better with that setup even before I changed PID controller.

[forest]

any vid of it flying? or pics

[atomiclama]

any vid of it flying? or pics

Yeah need to get some vid of it in flight.

As I mainly fly at night, dawn and dusk not sure how that will come out.

Need a way to mount my camera on my head as well, mmm bike helmet and duck tape me thinks.

Let';s see if I can get something over the weekend.

[quadfather]

I did start off with the QuadX mix, it flew but rolls were sloppy, I think the using the rear motors during roll tried to induce some yaw that upset things.

Anyway it felt much better with that setup even before I changed PID controller.

That';s what I meant, the angled tail motors clearly want a different mix. So why did they just copy the QuadX values in the code?  No wonder it was behaving odd when you tried it.

Glad you got it sorted.  Looking forward to a vid, too!

[kilby]

I';m fairly sure that there is a vtail type already in baseflight,  therefore it should be in cleanflight too.

The vtail option turned up without it actually being mentioned anywhere

[atomiclama]

there are both Vtail and A tail in clean flight

A tail is wrong which is why I';m down the custom mixer.

Need to raise a bug about it but not had the time yet, not sure how either as never done that before.