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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Jim Howell on August 19, 2012, 04:51:04 PM
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Okay, folks,
I have always been told to leave the leads from brushless motors and from the ESC alone. I have noticed that some of the installations appear to have shorter than "normal" leads from the ESC. So, my question is, "How sensitive are ESC's such as Castle Creation ICE Lites to slight variations in lead length?" I figure that I can clip off fairly equal lengths for the 3 ESC leads. But I don't know just how precise I can be. Any comments or guidance?
Thanks,
Jim Howell
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Jim,
From what I understand shortening the esc wires to the motor is not a problem. The wire length from the esc to the motor is insignificant compared to the winding length actually in the motor itself. I would not recommend shortening the wires on the motor as these usually have a coating that is very difficult to remove and make it very difficult to solder to the esc wires.
On another note, I have read that you do not want to lengthen the battery wires on the esc. Castle Creations recommends adding more capacitors to the esc if the battery wires are lengthened more than a couple inches. They have released a capacitor pack to be used when the battery wire is extended to suit the application. There is quite a bit written in regards to this on rcgroups.com. Extending the battery wire length is a documented cause for esc failure without the addition of extra capacitors.
Jason
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you can shorten the ESC wires as much as you like - you could even solder the motor wires direc to the ESC if you wanted to.
lengthening the wires creates issues.
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Jim:
While I can't offer any technical response to your question, I do believe that I have read in the product literature of motors and ESC's that there may be some warranty issues if one were to shorten the wires between them. So I would avoid cutting them if at all possible. If it is a question of positioning the ESC in the airplane, I understand that the same edict does not hold true to the wires between the battery and the ESC, they can be shortened.
On a related note, I recently built a scale plane that had the ESC's (2) in the body of the plane and the motors (2) in the nacelles in the wing. I had to lengthen the wires between the two about four inches. It worked just fine.
Jim Fruit
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Jason,
Thanks for the detailed response. I vaguely seem to recall some commentary about the motor wires, probably in the context of ultra-light indoor R/C flying where people had hard-wired the ESC to the motor to eliminate the weight of the connector.
I am most surprised by the comments about the length of the battery wires on the ESC. In my naive understanding, I would never suspected the length of battery wires to be a problem. I guess that means I need to pay attention to how I insert arming plugs. Because everything so far has been profiles, I've just used the battery plug/ESC connection as my arming system. That is changing, so thanks for the advance notice. I'll see what I can find on the CC tech support site for additional guidance.
Wynn, Jim,
Thanks for your responses as well. The comment about warranty issues may be where I heard/saw cautions about wire lengths, don't know, tho'.
Jim
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the reason you dont cut the motor wires is that they continue into the motor as windings - so you cant replace them (easliy) the ESC wire you can do whatever you like with - even solder new ones on if you like..... shorten to suit your needs. I have shortened many - and even lengthened them again to suit a new model.
you can add to the battery wires (within reason) as you say - you can do it to add arming plugs etc - I have and never had any issues
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I have shorten a number of motor leads and there is no problem with any of them. On a one motor the wires were coated with a varnish type insolator that had to be sanded off before the solder would flow, but it works just fine.
Andy
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-shorter cables are in any case better, so do not worry to shorten them
-long leads make resistance and current in motor leads is higher (ESC is a converter to lower voltage and plus current is chopped, so loses IIR are higher in that case)
-long battery leads make risc of voltage peaks (can kill ESC)
-long motor leads makes risc of erratic commutation
so if I can reccomend, keep it as short as possible, and if you extend, then battery lead and add some lowESR condensators if too long (follow the make rules, byt typically in case that it exceeds 10" )
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What Igor said!! Long battery to ESC wires may KILL you ESC!! y1
If you have to lengthen something then lengthen the ESC to motor leads. The shorter your leads the better.