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Permalink Reply by Taylor Cox on August 30, 2010 at 11:43pm

I just used an exacto knife and cut the channel deeper and wider to allow the wires to fit. After weeks of struggling everytime I had to get access to the motor and wire removal, I opted for two motors and props (one on each wing) secured with hot glue and a wooden mount.

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AdminPermalink Reply by Thomas J Coyle III on August 31, 2010 at 4:24am

Ground Loop,

You really should not have extended the motor leads on your ESC. Most ESC manufacturers will tell you not to increase nor decrease the length of the motor leads. Also, it is smart to mount the ESC in front of the EZ* motor mount for good air cooling. There is no air flow in the fuse and the ESC will become hot during extended periods of flying. I have built six EZ*s all with the ESCs mounted on the fuse just in front of the motor mount and never had an ESC fail.

Just a thought.

Regards,
TCIII

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ModeratorPermalink Reply by Sgt Ric on August 31, 2010 at 7:50am

That was my question as well... why extend the motor wires?
"upgrade" is what you called it, but it is not a good idea. Check your manual.

Like TC III said, the ESC is best mounted just ahead of the motor externally for best cooling.

(also, even though alot of people use the motor cooling access hole to run their wires, it's best to run them internally since most BL motors need all the cooling air they can get)

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DeveloperPermalink Reply by Michael Smith on September 2, 2010 at 9:14am

Actually, most motor vendors will tell you not to shorten the motor leads because you will have trouble removing the varnish to tin the new ends. 

Most ESC vendors will tell you not to extend the battery-side wiring on the ESC. 

The easiest way to get three 16ga wires to your motor, if it's an outrunner, may be to punch through the bulkheads under the wing and come out in the armpit below the motor. 

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Permalink Reply by Ritchie on August 31, 2010 at 9:45am

Use a sharp knife (exacto or scapel) to create a deeper channel either on both sides or just one.

I have done exactly this with my EasyStar build but have alter the airframe quite a bit already and am not finished yet. As for survival I will have to report once its been for a few flights. I have already marked where I might put aeration holes in the rear compartment but wont cut until I know I need it (cannot undo foam removal).

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Permalink Reply by Ground Loop on September 3, 2010 at 9:55pm

Thanks for the tips. From my bench-run tests, I have to agree that a foam-enclosed ESC looks like trouble. It heats up fast, and with zero airflow, it would cook itself and the rest of the UAV giblets. I'm going to mount it externally, in front of the motor mount.

(The motor is a 2200kV inrunner.)

I can't think of any harm, really, in extending or modifying the ESC-to-Motor wires. They're ordinary 16ga wire, and I imagine most folks here are skilled enough with a soldering iron to do it right. For outrunner motor wires, I totally agree -- those enamel wire bundles are really difficult to get right. I wouldn't do it. My motor has solder tabs.

Extending the battery-side wire seems like it has a few drawbacks -- increased cable loss (it's only 16ga), and possibly more magnetic field under high current.

All that said, I'm back to chopping the motor leads down, mounting the ESC outside the foam, and replacing the battery leads with 14ga wire. If the UAV gear gets warm, then I'm in with Ritchie in making some airflow holes.

Thanks!

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DeveloperPermalink Reply by Michael Smith on September 3, 2010 at 10:01pm

One issue with extending the battery-side leads is the increased inductance; the controller can compensate for the phase shift associated with extra wiring on the motor side (it just changes the motor's characteristics slightly), but not on the supply side.

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AdminPermalink Reply by Thomas J Coyle III on September 5, 2010 at 7:43am

@Michael,

The inductance issue of longer battery-side leads has been extensively discussed on RC Groups.

Solution: Attach a large capacitance (~100ufd) electrolytic capacitor at the input to the ESC.

Regards,
TCIII

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