BRArizona

My son and I built our 2nd R/C plane a Slow Stick Model with a 400 speed motor. We decided to go with the e-flite 20amp ECS, 1250mA, 3S, 10 C Common Sense LiPo drive system.

Plane went together fine, but we noticed the ECS was getting warm when testing. We took it out for our first flight and ran it around the field once and all of a sudden sparks started to shoot out the plane. We actually had fire. Since we live in AZ, rain is rare, and the grass was dry it was a concern. We have burn holes through the wings and the ECS was totally torched. We quickly disconnected the motor, battery, and yanked the ECS off of the plane. Sparks kept shooting out of the ECS even after we tossed the unit on the ground. It must have taken 5 minutes before we even touch it. I guess we just witnessed $35 go up in smoke. The worse part the plane never got of the ground more than 3 feet.

We were wondering if anyone could help explain what may have gone wrong. We verified with the local hobby shop that we had the right combination between the battery, ECS and motor.

Any suggestions before we try this number again. Is our combination of battery, ECS, and motor correct?

Thanks
BRArizona

Walt Thyng

My Feedback: (9)

There are a number of possibilities. Do you have a Whatt meter? Even on plug and play stuff you really need to check the amp draw before flying it. These Speed 400 motors are made by the thousands and given production tolerances, human error and whatnot, you're bound to get a bad one from time to time.

Causes: too big a prop, wrong gearing, bent motor shaft, bad motor bushing. However, I'd bet my money on too much LiPo; a three cell is pretty hefty for a Speed 400. My Slow Stick has flown for years on a two cell with plenty of performance.

I can also tell you that I recently had an FMA esc go up in smoke even though my meter showed the amp draw to be well within limits. Production tolerances again, I'll bet.
Walt

Dr Kiwi

What gearing and prop did you have on this 400 (and is it a 6v, or a 7.2v, nominal 400).

BRArizona

I appreciate your feedback. I stopped by the hobby shop where I picked up the plane. He suggested I buy a 30A E-Flite Speed Controller.

Your suggestion regarding the Watt Meter seems more logical. Detect what is the problem before burning up any more speed controllers.

The question I have: Does the Watt Meter get attached to the plane during flight or do you just take the prop off and plug the meter on between the battery and speed controller?

Based upon your comment regarding 3 cell LiPo vs. 2 cell LiPo, I did look at purchasing a couple 1300mAh, 2 cell LiPo's

The motor is from a kit. The specifications are Supplier: GWS, Model: EPS 400C - Brushed, gear box ratio: unknown, Prop Size: unknown.

The manual specifies battery to be 7.4~11.1V 2S1P and 3S1P, 1300~2200mAh Li-Poly.

Not sure if this helps with the detecting the problem. But I will certainly purchase at Watt Meter.

Thank you,
BRArizona

BRArizona

The specifications for the motor and prop were not contained in the instructions for this plane. See information regarding specifications listed in reply to Walt Thyng.

Thank you