SCX10 transmission question

[e32lover]

Hi, I have an SCX 10, has an issue, not sure if its normal or not. Basically when it is on the floor it requires a lot of force just to push it along. In comparison my wheely king almost will roll if pushed. If i pick it up it requires a lot of force to turn the wheels by hand.

I checked the axles and they spin freely, i have basically removed the tranny and the problem is definatley there. It is not a motor mesh issue.

What could the problem be? Is it possible that the slipper clutch is too tight? I installed a tekin FXR on 3s lipo and the ESC keeps on overheating and im thinking it could be due to this tension.

Any suggestions would be great, thanks.

 

[Bogncrawl]

It might be your drive shafts, if they are at a high pinion point it with be hard to roll

 

[Dingo74]

I had the same issue and it ended up being the skipper clutch was set to tight. Just back it off a half turn and see if it rolls easier.

 

[Dingo74]

That is supposed to be slipper clutch

 

[Jus]

Brushed motor? Still hooked up to esc? The capacitor feeds the drag brake even with the battery unplugged anddd even if it's discharged it's not going to roll easy with the gear reduction from pinion and spur gear and then trans. If you already know this than please disregard. If the tranny itself spins hard with no motor bolted to it or at least with pinion taken off, you definitely have a binding issue in the tranny.

 

[dkf]

Pull the trans and remove the motor pinion. Spin the input shaft to make sure it spins freely with no binding. If you crank on the screws to the transmission cases too tight you can cause binding in the trans. My slipper is cranked down tight and it has no affect on the rolling resistance. All tightening the slipper does is put more pressure against the friction disc to keep the spur gear from spinning on the input shaft.

 

[BadRockNoCookie]

If the motor is hooked up to the driveline, then this is normal. If the motor is not in the driveline, then this is not normal.

 

[Perkolator]

if all the driveshaft angles look ok, next i'd check the mesh between the pinion and spur gears. if it's too tight here, this will cause some serious free-rolling issues and will stress the motor considerably more. when everything's set correctly you shouldn't have much more resistance than what the brushes in the motor provide. slipper clutch should have zero effect on rolling resistance.

 

[pottymouth]

Tight or loose, the slipper clutch couldn't possibly cause this problem.

I can't tell from your description if you have actually narrowed it down to the transmission or if you've narrowed it down to the axles. Easy enough to determine. First, pull the motor. (I'm guessing that's where your "problem" is.) Without the motor, it should be 99% friction free. If it still doesn't roll freely without the motor there's definitely something wrong. Remove the transmission (or just the drive shafts). Each axle should spin freely and you should be able to turn the transmission outputs. That may be slightly difficult to get spinning due to the gear ratio, but it should spin easily once you get it going.

 

[Dingo74]

The dingo I had this issue with I just went downstairs and tightened the slipper down and there was no change in resistance. When I built my dingo the slipper was tight and I burned up a 20t traxxas stinger and noticed the resistance when I switched out the motor. I removed the pinion on the new motor and no resistance. I burned up that motor pretty quickly as well. After that I can't remember the sequence of events but on my post here mr.joshua asked if slipper was to tight so I loosened it, new esc and motor and no problems. Again I can't remember the order but I assumed it was loosening the slipper that fixed it.

 

[e32lover]

Thanks for all the help, much appreciated. I pulled the motor out, and there is no resistance in the driveline. I assume this is just the way the motor is. It strange though because I also have a wheely king that I installed a EZRUN brushless set up in and it has no resistance at all.

Since there is no resistance with the motor out can I assume the slipper clutch has nothing to do with it? Or would loosening it still lower the rolling resistance?

Thanks heaps for your help.

 

[BadRockNoCookie]

Thanks for all the help, much appreciated. I pulled the motor out, and there is no resistance in the driveline. I assume this is just the way the motor is. It strange though because I also have a wheely king that I installed a EZRUN brushless set up in and it has no resistance at all.

Since there is no resistance with the motor out can I assume the slipper clutch has nothing to do with it? Or would loosening it still lower the rolling resistance?

Thanks heaps for your help.

That is because you have a brushed motor in your scx10. That is where the resistance is coming from. That isn't a bad thing, it would be bad if there was no resistance with the motor hooked up. Sounds like you are ready to wheel. As for the slipper clutch, it needs to be just tight enough that it doesn't slip unless your truck's wheels are in a bad bind. You will notice if it is too loose because you will drive over a rock and the truck's tires will stop moving sometimes as though it lost power for a split second.

 

[Perkolator]

^to elaborate on this statement slightly more -- when this happens (the stopping) you should still hear the motor spinning when you lose drive, since that would mean slipper is doing its job. Without one, you could bind up the drivetrain and something will snap.

If you don't hear the motor spin/electronics and you lose drive, then it's a "brown out" caused by too much power draw through your ESC. This is caused by servo draining too much juice at same time as motor trying to draw lots of juice. This is why BECs are found on many rigs.