Ok, video 3...the first with the gimbal! Alexmos + Tmotor 2208's + cheap gimbal from china. $230 all in cost.The most noticable problem is the flutter in turbulence; I think the vibe suspension balls are too soft. Might need to find firmer balls, or even mount direct to the frame/legs.There is also some motor-induced vibration occuring at > 45' in pitch; I can't seem to tune this out.Settings for gimbal:Pitch: P25 I0.5 D20, Power 30Roll: P30 I0.5 D25, Power 60The high pitched whine was tune out by setting PWM to 16hz (ie "high").I also need to work on my flight skills - with the 14" props and fast descent, it really does cavitate badly, as you can see; introducing strong, long wavelength flutters, enough to spaz out the gimbal.Last 2 minutes interesting...Arducopter 3.0.0 without the compass calibrations done. Try and guess what happens...;-)
2 questions if I may....I have the same skids, do you have any other shots or description on how you have mounted the gimbal underneath the skids as there isn't a tray as such to take it.
Also, where did you source the low battery LED at the front of the quad attached to the skid, looks quite nice :)
Ok, as per request, here is the setup post modifications. Hopefully flutter should be eliminated, but only a test flight will check on the vibe situation. Except it's raining!
Quadframe "heavy" quad (www.quadframe.com) + DJI extensions, DJI board, 155mm legs. Motors: 3508-29's, props 1450 CF Tmotor clones (Original Tmotors are rare as hens teeth!). 2 x 4000 6S for main flight pack. Spektrum AR8000 + TM1000 (with full telex pack). APM2.5+ with all the bits.
The mount.
Soft balls replaced with 12mm M3 rubber dampers. Bottom plate removed to lift GoPro higher. Power cable routing from 2 x 4000 works better than it looks (it runs round the back, so no interference); the 10900 maxamps is much neater (but was downstairs in Garage at time of shoot). It doesn't affect COG too much this way. Not connected the SBEC either, which explains the loose servo cable. The SBEC will be used to power FPV in the future, which I will take direct from the GoPro using a media cable. Will probably go immersionrc 5.8ghz + OSD with blue beam antennas and fatshark goggles. Would love to use the MinumOSD, but I'm a muppet when it comes to wiring, and I need a "Y" shaped telemetry cable!
Gimbal from the front. Clearance in much improved. Gimbal camera tray very modified, as was the motor mounting method (it should be recessed) - the tray could only pitch 15' in each direction if I followed the instructions! It might only have been $35...but it was a royal pain in the ...., and I regret not getting something better designed.
From the back - close up. Servo cables running to RC channel 8 (pitch), and APM (for roll). It was running both through the APM, but the pitch control on CH8 was doing strange things to the stabilisation, so it's running straight from RC CH8 for now. I'm slightly embarrassed by my wiring mess....
Anyway, the APM, RX, LED's, Telem and the gimbal all run off a 850mAh 3S, which fits beautifully into the legs. APM, rx and Telem all run off the Xt60/Power module - Alexmos and LED's off the balancer port, which has a 6 way XT loom buried in the frame.
Will post some pics soon - I'm trying a different tack for the "too soft" balls first. If it works, I'll post 'em.
Essentially, I'm getting rid of the the rubber balls (I couldn't get them to work, even with ear plugs), and mounting the gimbal to the frame using Rubberised M3's on a wide footprint. I'm mounting under the legs, so away from most vibes at least, so should be stable enough. The added advantage is I reclaim some height under the gimbal - it was very close to the ground, and only suitable for tarmac landings.
I've got some foam tubing coming as well to add more clearance and softer landings (though my quad lands very well on stabilise and alt hold).
For video 4, I will also restore the normal field of view - I think we've seen the gimbal working ok ;-)
Slow yaw? Hmmm. Yes, so there is. I might try and trim that out and check my motor alignment. One motor is vibrating mor than the others - it might be on its way out.
Comments
Ironically, I took the BEC off, because it's it's not needed at the moment, and I get better low voltage data from the Spektrum telemetry.
Additional: If you use these skids, you'll know they don't take hard landings well. You'll need some foam tubing.
It's quite simple - I just drilled holes in the battery trays and the mount that came with the gimbal, and mounted it that way.
I used 4 of these to join it all together: http://store.jdrones.com/Anti_Vibration_M3x12_p/rubm312.htm
The trays are flexible, but with batteries in place they're ok.
The LED is actually part of a 3-in-1 BEC from Hobbyking: http://www.hobbyking.com/hobbyking/store/__31985__Turnigy_3_in_1_He...
Nice work Euan.
2 questions if I may....I have the same skids, do you have any other shots or description on how you have mounted the gimbal underneath the skids as there isn't a tray as such to take it.
Also, where did you source the low battery LED at the front of the quad attached to the skid, looks quite nice :)
All the best,
Steve
Ok, as per request, here is the setup post modifications. Hopefully flutter should be eliminated, but only a test flight will check on the vibe situation. Except it's raining!
Quadframe "heavy" quad (www.quadframe.com) + DJI extensions, DJI board, 155mm legs. Motors: 3508-29's, props 1450 CF Tmotor clones (Original Tmotors are rare as hens teeth!). 2 x 4000 6S for main flight pack. Spektrum AR8000 + TM1000 (with full telex pack). APM2.5+ with all the bits.
The mount.
Soft balls replaced with 12mm M3 rubber dampers. Bottom plate removed to lift GoPro higher. Power cable routing from 2 x 4000 works better than it looks (it runs round the back, so no interference); the 10900 maxamps is much neater (but was downstairs in Garage at time of shoot). It doesn't affect COG too much this way. Not connected the SBEC either, which explains the loose servo cable. The SBEC will be used to power FPV in the future, which I will take direct from the GoPro using a media cable. Will probably go immersionrc 5.8ghz + OSD with blue beam antennas and fatshark goggles. Would love to use the MinumOSD, but I'm a muppet when it comes to wiring, and I need a "Y" shaped telemetry cable!
Gimbal from the front. Clearance in much improved. Gimbal camera tray very modified, as was the motor mounting method (it should be recessed) - the tray could only pitch 15' in each direction if I followed the instructions! It might only have been $35...but it was a royal pain in the ...., and I regret not getting something better designed.
From the back - close up. Servo cables running to RC channel 8 (pitch), and APM (for roll). It was running both through the APM, but the pitch control on CH8 was doing strange things to the stabilisation, so it's running straight from RC CH8 for now. I'm slightly embarrassed by my wiring mess....
Anyway, the APM, RX, LED's, Telem and the gimbal all run off a 850mAh 3S, which fits beautifully into the legs. APM, rx and Telem all run off the Xt60/Power module - Alexmos and LED's off the balancer port, which has a 6 way XT loom buried in the frame.
And last shot from the back.
Will post some pics soon - I'm trying a different tack for the "too soft" balls first. If it works, I'll post 'em.
Essentially, I'm getting rid of the the rubber balls (I couldn't get them to work, even with ear plugs), and mounting the gimbal to the frame using Rubberised M3's on a wide footprint. I'm mounting under the legs, so away from most vibes at least, so should be stable enough. The added advantage is I reclaim some height under the gimbal - it was very close to the ground, and only suitable for tarmac landings.
I've got some foam tubing coming as well to add more clearance and softer landings (though my quad lands very well on stabilise and alt hold).
For video 4, I will also restore the normal field of view - I think we've seen the gimbal working ok ;-)
Euan,
Nice video showing excellent gimbal performance!
Can you post some photos showing your setup? Links to the products mentioned would also be very helpful.
Cheers!
Alexmos board - €110 - flyduino.net
Gimbal - $35 - goodluckbuy.com
Plus the postage = $230, depending on exchange rate and location.
-
1
-
2
of 2 Next