Frelon Why6 hexacopta

By daich on Jan 12, 2023

7  232  6

This build has taken me forever to finish. I think the two most frustrating builds (and rewarding) have been the octocopter and this hexactopter. Both micros. something about cramming all the ESCs and wires and extending 24/16 wires just makes it so easy to put off. And then having to mount the ESCs one way, soldering it up, only to find out the canopy standoffs are in the way, or the vista doesn't fit the other way is super de-moralising.
I got this frame mid may 2022 and finally finished it Jan 2023!

I can't believe this thing hovered on first arm haha...with FC upside and six motors to remap and configure and to add to all of that, a USB port that was coming unsoldered so I had to keep a finger on it to set it up.

Ever since flying the x8 and discovering the phenomenal throttle and yaw control I was convinced how nice they were to fly and cruise around. The octo build is great but 8 motors and 8 props are quite excessive. When I saw the Y6, I knew I had to try it out and see if it's a good compromise. Especially since there a micro version!

Ordering was simple enough, just a message to the creator on facebook. Frame arrived pretty quickly. Yay!
It came in two plastic bags, one for hardware and one with carbon and printed canopy. no packaging, no logo. no waste.
I asked for red canopy and got a black one. I asked for black in the rest of the printed bits...I got no other printed bits? odd.
The reply for the missing prints was that he's been really busy but he can send me the STL files to print. no comment on the wrong colour.

The carbon is of excellent quality. The arms are properly cut with the weave runing lengthwise. Some of the carbon one one side is lifted slightly on the cut surfaces, probably the cutter was at it's end of life and needed a change, only minor cosmetics but I could see someone complaining about that.
Interesting (and annoying) that the m2 arm bolts supplied are not 1.5mm HEX but either 1.4mm or 1.3mm

The arms mount to the top plate via 2 m2 bolts. There are no interlocking mechanisms

zeus 13a / omnibusf4 default:
resource SERIAL_TX 6 C06
resource SERIAL_RX 6 C07
resource PWM 3 C06
resource PWM 4 C07

change to:
resource SERIAL_TX 6 none
resource SERIAL_RX 6 none
resource PWM 3 none
resource PWM 4 none
resource MOTOR 5 C06
resource MOTOR 6 C07

This allowed me to connect TX6 and RX6 to the pwm lines of the second ESC. It works great.
All I did was find 4in1 ESC board where I fried one of the mosfets (got a stack of them!) and then just used two of them. It's like I have a spare ESC onboard!

You may be wondering why I chose different KV motors and different props for the top and bottom. Well, I read up on open air coaxial setups and it turns out the bottom motor/prop operate quite inefficiently.
If the props and the motors are of equal size and KV respectively, the brunt of the work is done by the top motors. On my X8 after hovering, the top motors are always hotter than the bottom ones.
Because of this I chose to run higher KV on the bottom to push the bottom props harder. Then I also used a smaller propeller which not only works better with higher KV but also it sits more within the clean air from the top propellers.

The indoor hover has a really cool whistling sound....albeit the bearing noise of the cheap motors were competing quite well volume wise.

16 Jan 2023
got some maiden packs in. it was also my first time with canvas osd on rooted dji - wow. thanks wtf.os team!
this thing is a cruiser. it doesn't like being upside down though...maybe too much resistance in the air with 6 props so it just stops in the air. It sure does like hugging the ground at high speeds though. the pitch control is awesome due to the rear two motors straight out the back. it reminds me of an old plus quad I had.
I did have one issue though, when I give it hard yaw movements, like a quick look back at an object, the motors rampup and I get a mini runaway. it very disconcerting. at first I thought it was the motor limits which I then tried without and it was still doing it. It may also be the mismatch of top and bottom KV and prop sizes. Will be reading up on how betaflight is mixing the Y6 setup and maybe making some adjustments
https://github.com/betaflight/betaflight/blob/master/docs/Mixer.md

Playlist of all flights on this frame

Photos

Discussion

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SQunX   17 days ago  
1

nice little build!
I like the odd ones

dafunk   18 days ago  
1

Hey man, thanks for sharing. That story reminds me of the pain I went through for some of my builds.

Very clever design... having a huge stack due to double esc and vista creates landing gear.

Sticky_RiceBowl   19 days ago  
1

Interesting take on a hexacopter and a really straightforward frame! I didn't know you could wire up ESCs like that. Can you perhaps include a diagram of how you did it? still a little confusing to me but I'd like to see if I can replicate the setup. I too have lots of 4-in-1 ESCs with 1 dead ESC.

daich   19 days ago 
1

Yeah, ESCs are pretty simple. you need power and signal for each ESC.
The power is connected in parallel with the two ESC 4in1 boards direct to the lipo.
then for the signal, any output pin on an FC that has a timer will work. Like UARTS, LED, PPM (Sbus i would avoid since it has a hardware inverter if it's an F4) or PWM which are marked as motor outputs anyway. You can't use the beeper pin.
In my case I used but UART 6 pins. you can see in the description how I repurposed it for motor output.
When I get some time, I'd be happy to draw up a crude MSPaint diagram haha.

Sticky_RiceBowl   19 days ago 

okay I'm excited now cause I didn't know it was that easy. Might try it out with my mamba stacks now that I have laying around. Do you have any references that you based your build from (like wiring basics)? If yes, may I take a look so you can have more time testing your new hexa out :D

daich   18 days ago 
1

I just hack my way through it. when I'm building I like to have all the pin out diagrams pulled up, that's all really...I've built a few too many of these guys. been slowing down lately though.
I flew one pack in horrible gusty winds this morning. It flies well! I think my KV is a bit high so may need a motor output limit.

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