Twitchity 250 Carbon Quad Emax Build

[Niall762]

First of all I'd like to give a massive thanks to Twitchity. I was fortunate enough to receive a free frame from him, and it's quite cool to have a frame that's unique.

The frame.


I quickly assembled it to get a rough idea of what it'd look like, and it looks nice. Very nice, dat carbon!

Then my box of bits arrived! I got these from buy.4props.com, if you're in the UK you should check them out.



So the parts I'm using are:

4x 12A SimonK ESC from EMAX
4x EMAX MT1806 Brushless Motor 2280kv
Naze32 Acro from AbuseMark
5030 Plastic Gemfan Style Props (4 props)
3S Turnigy 45-90C 1300mAh Lipo
Frsky D4R-II Receiver

So I quickly chucked all the parts on to get an idea of where everything was going to fit. I wasn't sure whether to mount the ESCs on the arms or the central plate, but I decided on the arms because I wasn't sure how I'd fit it all on the centre.



I soldered the motors directly to the speed controllers. This was quite tricky because the motor wires were enamel coated so i had to scratch it off with a blade, but they soldered fine after I did this.



All speed controllers soldered!



Next job, soldering these together for the power harness. I decided against a PDB, because I didn't have one. I found this was a useful trick to solder the wires together easily.



This is all I've done at this stage, but I'll keep updating! I decided to make a first post now so that if anyone has any suggestions throughout the build I can use them before it's too late. Also if there's anything that you'd would like me to talk more about in the build log please say. This is my first build log so apologies if it's a bit scarce of information.

 

[Niall762]

Reserved for part 3

 

[jhitesma]

Looking good! You probably already picked this up but those emax ESC's are actually running blheli even though they call them "simon series" but it's a modified version of blheli based on a few versions back. Still run well, but the default PWM setting causes the motors to make a lot of noise. It's well worth the time to "stick program" them with the higher PWM setting, and I found on my emax 1806 motors they seem to like the high motor timing better than the default medium. Oh, and they have a LVC enabled by default which should be disabled for multi use.

 

[Niall762]

Yeah I did notice that, is it worth flashing to the latest firmware? I'll definitely set the PWM setting to higher, thanks for that. I knew I'd have to reprogram them because I'll have to configure them to spin the correct way through the firmware as there are no connectors between the motor and the ESC. Any other tips would be greatly appreciated

 

[jhitesma]

Since they're silabs based and not atmel based reflashing is a bit trickier than with simonk based ESCs. You need a different flashing tool and they won't support the ability to reprogram/flash through the servo wire since the silabs chips don't have enough memory for that functionality. Unless you have an issue with how they perform I personally wouldn't worry about reflashing to the latest blheli.

 

[Twitchity]

Nice looking build Niall. I would definitely change the pwm setting on the EMAX ESCs if you're not going to reflash them. Adjusting the setting is really easy and only takes a few minutes. Can't wait to see the rest of the build.

Are you going to paint the arms before you do the final assembly?

 

[Niall762]

I've seen that you've painted G10 in some of your builds, I'd really like to paint it but I've no idea what paint to use, I was wondering about trying to dye them?

 

[jhitesma]

I just used cheap <$1 a bottle acrylic white from walmart in my airbrush to paint my G10 twitchity arms. Thinned it out with water to milk like consistency and it worked very well. I then covered that with actual spectra airbrush paint because I had it and it was brighter than the acrylics I had on hand

It's held up better than I expected...but did pull off when I removed my motors for repairs and where it was sandwiched between other plates. Oh yeah, and the tape pulled it up. Still those are all covered spots so it's still not visible. It's also easy to remove with some alcohol on a paper towel if you want to remove it and change to a different color.

I did give the arms a really quick light once over with some 150 grit sand paper first to give the paint a rougher surface to adhere to.

 

[Niall762]

I'll have a look at what paint we have in the garage lol, I'm thinking maybe purple. I'll do it as the last step so I don't have to end up repainting it! I've realised now that I've soldered in the right angled naze32 connectors in the wrong way (doh) so have had to remove each pin individually and consequently destroy the header. And now solder is stuck in the through holes on the pcb so I've ordered some solder wick to get it out. Then I'm going to solder the ESCs straight to the board. I'll get there eventually!

 

[FlyingMonkey]

Very interesting looking!

 

[Twitchity]

I just used regular spray paint which seemed to hold up fairly well. Just give the arms a light sand like jhitesma said and spray away. I didn't use anything special, just whatever cans I had laying around the house.

 

[Niall762]

I think for now I'll leave the arms as they are, and when I get more confident flying I'll probably paint them then. Out of all the motors I soldered, only one is spinning the wrong way, so I'm quite fortunate that I only need to desolder and swap two wires! Hopefully I'll be flying in the next couple of days.

 

[FlyingMonkey]

Niall, I have been removing the heat shrink from the ESCs, removing the lead wires (if they're too short) and solder right to the motor wires. If any leads needs swapping, I do it at the ESC, and then once it's all good, I replace the heat shrink on the ESC.

 

[Niall762]

Exactly what I've been doing though unfortunately because the solder pads on the esc aren't all in the same place, when I cut the motor wires to the right lengths to match up with the pads it didn't occur to me that if I needed to swap them the lengths would be wrong. I had to then extend one of these motor wires to resolder it. I then painted all the speed controllers with nail varnish to waterproof them, I'll be doing the same with the naze and receiver tonight! I can't wait to get this thing in the air!

 

[Niall762]

As with most build logs, the more I've done the less I've actually written up. But today it flew! I flew with the rates turned down low while I learn acro mode, (sadly I've only ever flown in stabilise with APMs :/ ) but it flew 'great' as Josh would say.



I've got no photos of the last few parts, but for those interested I painted the speed controllers, receiver and naze32 with nail varnish to waterproof them. I'm not sure how well this will have worked, but I just wanted a little more protection as I want to fly in the snow this winter. I have also spent a good couple of hours sorting out cleanflight on the naze32 (failsafes, PIDs etc) and while I still have more tuning to do so far I'm amazed with how stable it is. Sadly the weather at the moment is very windy, but hopefully it'll clear up for Christmas.

I can't wait to have a go at flying fpv with this thing and get the mobius on!