Replies to This Discussion

Permalink Reply by Greg on October 8, 2011 at 1:35pm

They certainly look similar, particularly the internal construction photo.   They could be from the same manufacturer just re-badged?

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Permalink Reply by arashi on October 8, 2011 at 2:44pm

All I know is that my 2830-14 750kv's have over 4 hours of actual flight time with no problems other than 2 bent shafts from crashes.  I bought extra shafts for 99cents and it only takes about 5 min to change them out with my hydraulic press.

I did lube the bearings.

I have larger rctimer motors on my fixed wing stuff and have yet to have any problems.

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Permalink Reply by Greg on October 8, 2011 at 3:07pm

Good to know you have been getting reliable use out of your 750s and can get new shafts for them. The 880Kv tolerances can vary so with the grub screw not tight enough the shaft can be easily moved by hand. Like you mention, the shaft should normally be a press fit in the outer casing.

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Permalink Reply by arashi on October 8, 2011 at 3:19pm

All the shafts on the 2830's were a definite press fit.

I've never had a bent shaft until using these motors.  The shafts are just too long and especially so with the prop adapters that are included.

I ordered from rctimer, some shorter shafts and different mounts that should alleviate the bent shaft problem.

BTW, I have extra bearings, but haven't had to use them yet.  The only times I've had bearing problems is when I crash in the dirt and the motors attract every ferrous particle from miles around...

 

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Permalink Reply by Greg on October 11, 2011 at 1:24am

Well I have finally had enough with these jDrones 880Kv Motors.  I have not been able to get any real flight testing in since building my quad, because every time I replace another motor I am back doing the same thing again or flight or two later.  Last night (luckily) I was running the motors at hover throttle doing some sensor electrical and mechanical sonar noise testing when the forward facing motor on my arducopter shuddered and failed a few moments later.  All motors were running for about 4mins and there was no warning or other interference to cause this (no bad wiring either).  Had I been flying at altitude that would have been another expensive re-build in as many weeks. So in total 6 x 880Kv motors out of 10 from jDrones have given me trouble and no resolution in sight.

 

Can someone positively confirm the DiyDrones 880Kv's are from a completely different supplier than jDrones.   I still want to stay on the same arducopter test platform  and need the extra lift from this choice of motor offered for the arducopter.  I have some good advice from other forum members and the AXI's or Pulso's are on my shopping list but not for my initial test quad.  I have even been thinking about perhaps a Kv equivalent from Eflight.  I have these motors in several helicopters and one Blade 400 with 50 hours flight time with no issues.  Compared with the 30-60 minute life of the 880Kvs, I have to find better reliability,

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3D RoboticsPermalink Reply by Chris Anderson on October 11, 2011 at 7:19am

Are you soldering your motor connections, or still using bullet connectors? I find that if you don't solder, these intermittent drop-outs are much more common, regardless of motor type.  

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Permalink Reply by Greg on October 12, 2011 at 5:05am

Chris this is a excellent point you make.  I use good quality bullet connectors just to make sure the motor is turning the correct way and then solder the connections.  Actually I use the socket end of the connector and solder the wire in each end and cover with heat shrink.  I am chatting with Jani via email now to send back some of the motors to have them looked at. This can only help improve things over time :-)

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