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View Full Version : Should motor leads be soldered on or can the eyelets be used?


Eman
2010.07.15, 07:32 PM
I've heard if the eyelets on the motor leads get loose and touch something they aren't supposed to you can burn FETs. Is this true? I've been staring at this board and on the top it looks like the part marked C4 is making contacting with both positive and negative motor pads. On the bottom of the board it looks like only the positive motor pad is making contact with C4. So I guess I want to know what I'm supposed to avoid with the motor leads. I really don't want to solder them on but will to avoid replacing FETs. However I would prefer to use the eyelets to help secure the board itself. If anyone can shed more light on this I would be grateful.

http://i85.photobucket.com/albums/k41/willis67017/Mini%20Z/24.jpg


http://i85.photobucket.com/albums/k41/willis67017/Mini%20Z/241.jpg

chad508
2010.07.15, 08:42 PM
only seems to be a problem on the 03s. i still use the eyelets. if you do not you have no way to mount the board. i normally just sand the eyes down to the same size as the screw head.

color01
2010.07.15, 08:51 PM
Before installing a new motor, I made sure to cut the eyelets on aftermarket motor wires into a square shape that would fit on the pads. The two motor terminals do come dangerously close on the MR-03 board. For security, I eventually just soldered the wires on -- securing the board is pretty well accomplished anyway with the wires tucked in underneath the MR-03's PCB cover.

Eman
2010.07.16, 01:17 AM
So its only a problem on the 03? Ok. I'm guessing its still not a good idea for the eyelets to touch anything near the motor pads on the MA or 02 boards? So is it the part C4 that needs to be avoided? It looks like it contacts both motor pads (on the top anyway) is why I'm a little confused . The board I'm working on is a MA. Thanks for your response.

Eman
2010.07.16, 03:15 AM
So I decided to put the motor leads under the MA board. Sandwiched between the board and screw boss underneath it. The bottom of the board looked like it had more room. Had to dremel a little of the screw boss piece to allow the eyelets in. Took about 1mm off the diameter of the screw heads. Feel a little more relaxed about not shorting out. Anyway it works. However it does this funny thing. When I put the batteries in the car, the motor kicks on for a sec and shuts off and acts normally from then on. I'm thinking its probably the way I bypassed the switch. Any info would be appreciated.

http://i85.photobucket.com/albums/k41/willis67017/Mini%20Z/DSCF0892.jpg

chad508
2010.07.16, 10:37 AM
you way want to check the bottome of the board as there are also fets and solder tabs under there as well

Eman
2010.07.16, 04:02 PM
Yes I did check. The second photo from the top. It looked cleaner / roomier? I didn't want to worry about shorting C4. Actually I'm not sure thats even a worry but yeah I checked. I ground down the top of the eyelet so its flat. So it wouldn't contact the FETs. I don't know if thats a concern either. It looks like all the legs of the FETs go to the pads so I'm not sure I need to sweat it but I'm gonna err on the side caution anyway.
I redid the switch bypass. The positive now goes to BAT and S1 first. It still spins the motor when I first batteries in it. Maybe thats normal. I don't know. The only experience with 2.4ghz I have is with my MR-02 and it doesn't do that. Kinda weird.

chad508
2010.07.16, 04:24 PM
the problem with the c4 is on the 03 board. it is turned 90* which allows you to short both sides together. as far as fets you are correct in they connect to the eyelet anyways so no chance of them shorting.

Eman
2010.07.16, 07:08 PM
I see. So there should be no problem with using eyelets on MA boards? No chance of shorting anything on the top of the board if the eyelets move a little?

chad508
2010.07.16, 08:09 PM
anythings possible.

Felix2010
2010.07.16, 08:51 PM
I have to say that mounting the eyelets under between the PCB + Chassis is a great idea, just as long as they are torqued-down tight. Great idea, thanks for posting this:)

color01
2010.07.16, 09:01 PM
The power-on motor "jerk" seems like a common/normal occurrence. I experienced it with a bone-stock MA-010 right out of the box, it ran perfectly fine. So I don't believe it's a problem with your electrical work. ;)

Eman
2010.07.16, 09:05 PM
color01: Thanks. I've run 3 sets of batteries through it this afternoon. Checking the screws everytime and they don't seem to be getting loose. But yes its something I'll be checking before and after every run.

Eman
2010.07.16, 09:06 PM
The power-on motor "jerk" seems like a common/normal occurrence. I experienced it with a bone-stock MA-010 right out of the box, it ran perfectly fine. So I don't believe it's a problem with your electrical work. ;)

Thanks good to know!