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View Full Version : Elec. Problem with my brushless DT, experienced help please!


THE EDJ
01-28-2009, 08:24 PM
So I'm having this problem with my DT. The truck will only run for about 5-6 seconds at a time, which at that point, the motor is slowed to a complete stop. This happens in any position; in the air, wheels free to move, and on the ground, rolling, forward and reverse. I have no idea what the problem is. I'm running the LOSI brushless ESC, 10250 kV motor, JR micro servo, and a Team Associated RC18 radio and receiver. I've configured the ESC so many times, hoping that it will solve the problem, reset it, and reset it, and reconfigured it again. And again. No solution.

It's been like this since the day I bought it. Originally there was a bridged solder joint, connecting the negative from the battery (black wire), and the negative wire to the servo (brown wire). I removed the bridge and resoldered the wires, but it didn't solve the problem.

My batteries are charged, the remote has full battery, the ESC is getting power... everything should be working fine, but it's not. Any help would be greatly appreciated. I've put a lot of money into this truck and it's being held back by some stupid little problem.

BART
01-28-2009, 08:47 PM
The first obvious guess I would have is a lose connection or poor solder joint, either would cause excessive heat in the suspect area. Do you notice anything getting hot? the motor? the esc? the battery wires? The next step would be to start measuring voltages in different areas before and after the problem. Measure battery voltage where the wires connect to the board when it runs good and again when it will not move, this will tell you if you have sufficient voltage to the electronics, you must do it under load though as transient voltages under no load can fool you quite easily. If that checks out measure AC voltage on 2 of the 3 motor wires, and then again on one you already checked and the third (i hope that makes sense). Do this once again with it running good and when it is not. The next step in my opinion would be to start swapping out known good components to track down the problem.

Edit; If you at all suspect your battery pack you could hook it up straight to a dc motor and see how long it lasts, lith cells will show a good surface charge but as soon as a load is introduced they can fall below operable voltage.