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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Mike Scholtes on January 03, 2010, 10:34:56 AM

Title: OK to lengthen ESC leads to battery and motor?
Post by: Mike Scholtes on January 03, 2010, 10:34:56 AM

I am having a devil of a time fitting the Castle ICE 50 ESC into the China Clipper. It would be great if I could relocate it outside the engine compartment, like under a removable canopy (where the timer already resides). I would like to add about 3 inches to the leads between battery and motor and ESC. Currently total length of motor-ESC is 6.5", battery-ESC is 10.5". Assuming use of same gauge and type of wire, is there any harm in adding about 3" to length of each? Battery is Turnigy 5S 3300, motor is Turnigy 42-50 650kv.

Title: Re: OK to lengthen ESC leads to battery and motor?
Post by: Alan Hahn on January 03, 2010, 10:49:56 AM

Mike,
3 inches or so shouldn't be a big deal at all to add to either or both sides of the ESC.

CC claims not to add a lot more to the battery-ESC leads without increasing the capacitor size at the input side of the ESC (3" is not a lot!).

To be honest, I don't understand the reasoning (claims it is due to added inductance of extra leads), but that doesn't make it wrong. I guess they have seen what will blow their ESC's.

On the other hand, there seems to be no issue with increasing the ESC-motor length. After all, there is a lot of wire already inside the motor (about a meter or so in the winding of each leg)

Title: Re: OK to lengthen ESC leads to battery and motor?
Post by: Mike Scholtes on January 03, 2010, 06:44:27 PM

Thanks, Alan - that helps a lot. This is a fairly short-nose design without much room for the components and mounting the ESC approx at wing high point under the (removable) canopy makes life a lot simpler. At least in this respect. Also helps the CG with this rather heavy ESC. Maybe next one will be an ICE lite.

Title: Re: OK to lengthen ESC leads to battery and motor?
Post by: walterbro on January 04, 2010, 09:09:43 AM

Mike - I agree with Alan . I have extended the battery to ESC wires on both of my
twins. The two ESCs are in the naceles and the battery is mounted in the forward
fuse. Their is no problem in over 2 years of flying. Approx 6" was added to each
ESC.

Walt

Title: Re: OK to lengthen ESC leads to battery and motor?
Post by: Igor Burger on January 04, 2010, 09:47:59 AM

It should not be over 10" ... if yes, it should have low ESR capacitors in middle of leads. You must remember, that unlike DC motor on PWM, we cannot have capacitors on motor leads, and current going via diodes in FETs are CHARGING current on battery leads, while it goes only locally on DC ESC, so long battery leads can lower effectivity in some cases. Capacitors are helpfull, bacause they catch such backwards currents.