KAN950 making my servos stutter! - RC Groups
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Feb 29, 2004, 08:06 PM
rmasonjr's Avatar

KAN950 making my servos stutter!

Not sure if this belongs here or not....

I have a brand-new KAN 950 - cycled once on a triton.
I mounted it on my Slow Stik with a GWS 350 and 11x8 prop with an ElectriFly C-10 speed controller. The servos are JR 331 servos. When I go full throttle-up, the rudder servo starts twitching wildly and going crazy.

Formerly, I was using qualcomms on the Slow Stik without any problems.

Could it be that the 11x8 is drawing too many amps through the C-10? I only have 9x7s and I don't think those will work too well.

Thanks in advance...
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Feb 29, 2004, 08:28 PM
FLYER spelled I-squared-R
fliir's Avatar
You didn't tell us how many cells of KAN950 you are using.

It is possible you are loading down the system (this includes wires, connectors, etc.) enough that the C-10 can't supply adequate voltage to the radio system. There are other possibilities as well. Start by telling us the cell count.

Feb 29, 2004, 09:27 PM
rmasonjr's Avatar
sorry - it's an 8-cell KAN 950

Feb 29, 2004, 09:48 PM
A loose weld/solder joint. Bad plug connection might cause this. See if putting pressure (twisting and pushing at various places) on the battery while pluged into your plane with Tx and rx on causes the twitching to stop or get worse.

Mar 01, 2004, 06:47 AM
Crash Master
Gene Bond's Avatar
May just be the increased noise of the motor at the higher speed and load due to the higher voltage. Double check your capacitors on the motor.
Mar 01, 2004, 10:15 AM
Registered User
An 11x8 prop is an awful lot for an EPS350C on 8 cells. What gear ratio? Try a 9x7 prop.
Mar 01, 2004, 10:20 AM
rmasonjr's Avatar
The caps appear to be in place...

It's the 'C' gearing. I was afraid that the amp draw would be a little much for the C-10. I'll try a 9x7 tonight. Ultimately, I think either an 11x6 or 12x6 might be better.

When an ESC's amp limit is exceeded, shouldn't it just shut down? Maybe that's what it's trying to tell me...

Mar 01, 2004, 12:14 PM
Space Coast USA
hoppy's Avatar
When an ESC's amp limit is exceeded, shouldn't it just shut down? Or SMOKE.... Does it have an overcurrent limiter built in? Check specs -

The overload protection just shuts off the motor -
"Battery Eliminator Circuitry provides sufficient current for the
receiver and two micro servos. The motor battery powers the
receiver and servos, then when voltage is reduced to 3.7 v, the low voltage cut-off circuitry stops the motor while continuing to supply power to the receiver and servos. Built-in thermal shutdown protection turns the motor off if the transistors overheat."

Sounds like electrical interference ot the RX.
Last edited by hoppy; Mar 01, 2004 at 12:20 PM.
Mar 01, 2004, 12:17 PM
Formerly of mcba fame
Matthew Allen's Avatar
Originally posted by mkirsch1
An 11x8 prop is an awful lot for an EPS350C on 8 cells. What gear ratio? Try a 9x7 prop.
I think that may well be a factor. AFAIK, 10x8 is considered to be about the limit for your motor on 8 cells.

Mar 01, 2004, 01:28 PM
rmasonjr's Avatar
hoppy - you might be right. That's a brand-new 350 that I put in there. The only break-in was to put a drop of oil on the bushings.

I think I'll drop back to the 9x7 or 10x8 and try it out.

Thanks, guys!