Mark Jones Posted November 13, 2007 Share Posted November 13, 2007 I need to extend some wires in my multiplex funjet. Not sure wich ones esc-motor or li-po Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 13, 2007 Share Posted November 13, 2007 preferably the ESC to motor. Quote Link to comment Share on other sites More sharing options...
Michael Dearden Posted November 16, 2007 Share Posted November 16, 2007 The instructions for my Multiplex ESC, I'm flying a Gemini, states that you should keep the ESC to motor leads AS SHORT AS POSSIBLE to prevent excessive radiation and that any lengthening required should be on the BATTERY to ESC side, making sure you use cable of adequate current carrying capacity. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 16, 2007 Share Posted November 16, 2007 Well I am sorry but I beg to differ - let me try and explain in simple terms why this is wrong.All wire and motors are "inductive" that is they can potentially produce an electrical force ( emf ), all of their own when a current is passed through them - especially a rapidly switching /changing current like that produced by ESCs. If you allow long leads from the battery to ESC then the ESC does not "see" the battery, and these high voltage spikes are not damped down and can actually reach the input stages of the ESC and blow the MOSFETS ( fancy and clever transistor varients ).The battery itself is able to damp out these "spikes" ( which can reach into the hundreds of volts incicdentally ) ONLY IF the leads from the battery to the switch (ESC) are short enough to not produce their own spikes. When possible, the TOTAL lead lengths of ALL wiring, including that from the battery to ESC and the ESC to motor should be limited to around 15" MAX.If further "evidence" is required, please see the following quotation from the tech director of Castle Creations - an american firm producing ESCs"If you have to extend any wires ALWAYS extend the motor to ESC wires. Extending the battery side induces voltage ripple and kills controllers. The worst that can happen extending the motor side is the motor fails to start...if this happens, resolder all connections. If it still doesn't work, try another motor. Do not keep hitting the throttle as the current will build up on the MOSFETs and can potentially blow the controller. I've seen as much as 24" of wire extension on the motor side!! If you absolutely HAVE to extend the battery wires make sure the packs you are using are FULLY capable of supplying 1.5-2x the current you will be drawing. DO NOT trust the lipo manufacturer specs...if it says 20-30C, treat it as a 10-15C and use packs in parallel accordingly...better safe than sorry"Joe Ford. Castle Creations technical product specialist. Quote Link to comment Share on other sites More sharing options...
Michael Dearden Posted November 16, 2007 Share Posted November 16, 2007 Thank Timbo. Not too proud to admit a boo boo. Wonder where Multiplex are coming from then? I'll get with them and check.Regards Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 16, 2007 Share Posted November 16, 2007 No problem Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted November 17, 2007 Share Posted November 17, 2007 hi all i totally agree with what timbo is saying extending battery side of an esc is a no no. i've done it once and was lucky to get the plane back before it hit terra firma. i have extended battery cables in an edf under the guidance of J Tinka from Jeti who was kind enough to send me some capacitors to smooth out the voltage spikes that are induced into the cables but i must stress this was done with some knowledge of eletronics and electrical installations. so only ever done under the guidance of the esc manufacturers.multiplex are on their own with this statement and to be honest we followed multiplex advice in my first Funjet and it only lasted 30secs before the model was re-kitted. so i would not be that inclined to follow their advice to the letter in future.regardsnasa Quote Link to comment Share on other sites More sharing options...
Michael Dearden Posted November 17, 2007 Share Posted November 17, 2007 Hang on nasa. You're saying one thing in one sentence and another in another. No wonder people get confused!Your first statement "i totally agree with what timbo is saying extending battery side of an esc is a no no"Timbo is NOT saying this, he is saying extend the MOTOR SIDE of the ESC, NOT the battery side! Please check statements before posting them. Poor old Mark will think us a right bunch of twits! Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted November 17, 2007 Share Posted November 17, 2007 MICHAEL PLEASE READ AGAIN WHAT I SAID!!!!! extending battery side of an esc is a no no" NO NO MEANING DO NOT DO THIS!!!!! BEFORE YOU BERATE SOMEONE MY FRIEND PLEASE MAKE SURE YOU ARE BERATING CORRECTLY!!!!!!might i suggest that YOU read the statements correctly before you get on your orange box!!! Quote Link to comment Share on other sites More sharing options...
Michael Dearden Posted November 17, 2007 Share Posted November 17, 2007 SOOOREEEEE NASA. Having a "senior moment"!!!NASA IS ABSOLUTELY RIGHT AND I AM A COMPLETE PRAT WITH MY PREVIOUS COMMENT!CAME IN FROM WORK, SCANNED THE REPLYS AND MADE A PIGS EAR OF IT!MY APOLOGIES. PRETEND I NEVER CAME ON THIS FORUM!BYEEEE!!! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 17, 2007 Share Posted November 17, 2007 LOL Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 18, 2007 Share Posted November 18, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Michael Dearden Posted November 19, 2007 Share Posted November 19, 2007 Age is a great contributer to this sort of gaff! The important thing is not to be too proud to admit when you're WRONG! (you get sort of used to it)LOL Quote Link to comment Share on other sites More sharing options...
Mark Jones Posted November 21, 2007 Author Share Posted November 21, 2007 Thanks to all you guys for the advice-its been taken on board!!! Mark Quote Link to comment Share on other sites More sharing options...
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