Aeronavics / Droidworx XM-6 build nearly complete, any advice or criticism very welcome!

[barnytj]

I'm in the process of completing a new build - based on the Droidworx XM6 frame. I'm not a complete newbie, but this is my first build from scratch.. previously I've put several flamewheels together and done a complete rebuild of a Skyjib 8 (after catastrophic failure)..

Frame: Droidworx XM6 - with extended landed gear
ESC: Hobbyking 40A Opto with default settings apart from medium timing
Motors: Axi 2814/22 (765kv)
Battery: Single 4S 8000 mah 30C
Props: Graupner 12 X 6
Flight Controller: Naza with GPS
Basic Gains for FC: Pitch 170 Roll 170 Yaw 150 Vertical 140
Attitude Gains for FC: Pitch 170 Roll 170
TX: Spektrum DX8

Gimbal: Photohigher AV200 with RSGS
Camera: Sony Camcorder
Video Tx: 5.8Ghz

I have just done a test flight without the gimbal, but with an extra 1kg battery to simulate weight and all seems good..

I am about to set the battery limits in Naza Assistant - I do know that dual batteries would be preferable, but I already has these ones for my Skyjib, and due to limited funds couldn't stretch to new ones.. the same goes for the FC - I intend on eventually using WKM, but had a spare Naza kicking about.

I will obviously keep a good eye on temperatures of battery, ESCs and motors - does anyone have any tried and tested ways of pushing these to their limits without putting the craft and any real risk? Or does anyone have a similar setup that can share their experience, or point out any concerns?

Many thanks

Barny

 

[redridinghood]

Tie the hexa down on a heavy item. Give it full throttle with the props one for a few moments while on manual mode. Check lipo voltage sag and temperature on motors, esc's, lipo and lipo plugs. If after a couple of lipos everything still works you are good to go.

 

[barnytj]

Tie the hexa down on a heavy item. Give it full throttle with the props one for a few moments while on manual mode. Check lipo voltage sag and temperature on motors, esc's, lipo and lipo plugs. If after a couple of lipos everything still works you are good to go.

Sounds like a good plan - I might not attach the lipo to frame, though - just in case it does burst into flames in horror!

 

[barnytj]

Having done the above test.. all seems to be ok, but the motors are getting a little hot..

I'm also not getting great flight times, most recent being 6 minutes leaving the battery at 22% (certainly don't want it getting lower than that).

I think I need to get hold of a proper IR thermometer as my current scale goes from ambient, warm, getting hot to touch, hot to touch, to damn hot.. Whereas hot to touch means it's uncomfortable to hold onto - and this is where the motors are! Obviously this scale depends on how asbestos your hands are..

I would be grateful if anyone knows up to what temp these Axi motors are safe to operate up to?

 

[redridinghood]

You want to keep the motor under 60C degrees. Since many others are running your motors on 4S with larger props for some time now I wouldn't worry too much about temps.

 

[barnytj]

Thanks redridinghood.. I will get a thermometer to check the exact temps, but is good to have a benchmark to work with..

I have to say, in spite of short flight times, the machine is absolutely awesome in terms of handling - much closer in terms of performance to a F450 flamewheel than the bulky Skyjib - a real pleasure to fly!

I'm meant to be using it this weekend for filming the first stage of the Kenya National Rally Championships, so got to finish testing by then! Doubt I'll get much better flight times without changing the batteries.. there isn't much weight I can strip off it, and slightly bizarrely got a very similar flight time when I swapped the sony camcorder for a much lighter GoPro2.. but on another positive note the vibration damping on the frame is superb - not the slightest bit of rolling shutter on the GoPro.

Although it looks much like any other XM6 - here is a pic for anyone interested
View attachment 9134

 

[nicwilke]

Looks great.
I'm flying the XM-6 also View attachment 9135
Its a good rig. I suggest if you are using a light camera, throw in the yellow vibration rubbers, as they seem better for small cams.

I've tried a heap of props on mine, and think APC 12x3.8's to be the best. I am trying Xoar 12x5's and I need to dial out a wobble I get under hard throttle. I'm running a ZeroTech YS - X6 16 waypoints and data link on mine. Would be glad to trade notes.
I'm on Avroto motors now, not too bad.

View attachment 9136

 

[redridinghood]

Don't forget to range test your Spektrum RX before flying near people. If your lipos are new they will give better performance after a few cycles.

 

[barnytj]

Looks great.
I'm flying the XM-6 also View attachment 11820
Its a good rig. I suggest if you are using a light camera, throw in the yellow vibration rubbers, as they seem better for small cams.

I've tried a heap of props on mine, and think APC 12x3.8's to be the best. I am trying Xoar 12x5's and I need to dial out a wobble I get under hard throttle. I'm running a ZeroTech YS - X6 16 waypoints and data link on mine. Would be glad to trade notes.
I'm on Avroto motors now, not too bad.

View attachment 11821

Your rig looks very tidy indeed.. hope to get mine a bit closer to that once I have finished tinkering.

I would have used the yellow tabs - but as I am running on a single lipo I have put it on the front of the AV200 - as that is as close to the COG as I can get - so the extra 800g makes the red tabs necessary.

I haven't had the luxury of testing other props on my rig, but have found graupners to be good in the past, I do use Xoars on my Skyjib, and can't help but notice and like the use of the aluminium washers on yours.

happy to trade notes - do you mind if I start by asking what your AUW is and what batteries you are running?

 

[barnytj]

Don't forget to range test your Spektrum RX before flying near people. If your lipos are new they will give better performance after a few cycles.

The Spektrum Rx has been truly tried and tested on an F550 flamewheel.. sadly the lipos are not new, would have gone 5s and dual lipo if I could have justified new batteries!

You have to be quite wary doing the range test with a Spektrum DX8 as it limits the power output, so if you don't power cycle it after your test you remain at a very limited power output.

 

[barnytj]

My AUW is a fairly hefty 5.1kg - although the Hex still handles great, I am only getting 5 minutes of flight time if I want to keep 30% in the lipo.

 

[nicwilke]

I get just under 10min.
I am at 4900g

AVROTO 770KV, 40A ESC's and 12x3.8's APC's.

 

[SamaraMedia]

Nic, what esc's are you using?

 

[nicwilke]

stock plush

 

[barnytj]

I get just under 10min.
I am at 4900g

AVROTO 770KV, 40A ESC's and 12x3.8's APC's.

Nic, what Lipos are you using??

 

[barnytj]

Still need to tweak the RSGS a bit - but not totally upset with the results I'm getting, especially as it was quite windy.. will put the rig through its paces on Sunday filming a stage of the Kenya National Rally Championships..