Slipper Clutch...?

[stbob]

Just locked and loaded a fully charged battery into a new mini e-revo. Have it set on min power. First thing we noticed was when just barely giving it some throttle, its making a clicking noise. We think the noise is coming from what we think is the slipper clutch, if so, is this normal or should we tighten it up a bit. Under heavier acceleration it seems to be okay. Here's a sampling of the sights & sounds...

[grizzly03]

That noise is "brushless motor cogging." It is completely normal. It only happens on slow take-off, when the motor just tries to turn. Giving it more throttle the cogging goes away. Without sensors in the motor itself the ESC doesn't know where the rotor is in it's rotation.

[ThatTraxxas]

Just gonna say I have that too and it’s normal. Your completely fine.

[stbob]

That noise is "brushless motor cogging." It is completely normal. It only happens on slow take-off, when the motor just tries to turn. Giving it more throttle the cogging goes away. Without sensors in the motor itself the ESC doesn't know where the rotor is in it's rotation.

Just gonna say I have that too and it’s normal. Your completely fine.

Thanks...
In my quest for knowledge, i also read some of the manual and found how the slipper clutch works and how to adjust it. For now going to leave it set at the factory setting... Thanks again...

[Squeegie]

Never assume that the factory settings are correct.
It is always best to tune to your personal preferences.

Have fun!

[RCWilly]

Yes, as others said above, it is normal for 4-pole sensorless brushless motors to cog a little bit on low-speed startups. If you don't want a smoother low-speed startup, you can get a sensored brushless motor.

[halygon]

When mine was new last year, I heard the same immediately. For me I did have motor cogging - not much to do about that. But I also had two other issues that did make it smoother:

1. Set the gear mesh better - mine came out of the box a bit loose, once I got a good mesh the drivetrain became smoother
2. The slipper clutch plate was rubbing on the gear box as seen below. I sanded down the box plastic till it didn’t rub and beveled out the aluminum plate to give more room.

[stbob]

I cranked down of the slipper clutch to see if it would make a difference, it didn't. I took much of the mini e apart to check the gears for damage, they all look good. I did see the slipper clutch pad looks worn flush with the gear so the clutch plate is unable to exert any force onto it no matter how tight you tighten the spring nut. I thickened the pad with a temporary backing. This seemed to help some but something in the trans feels like it still slipping at slow speeds. Not sure i fully understand the brushless motor cog, will resume my quest for knowledge tomorrow. Thanks again for all the replies...




Thanks for all the replies. This morning read up and watched a few videos on cogging, could of probably saved me a few hours had i done that initially. But all in all had fun stripping down and being able to put back together the mini and more confident in my abilities. The downside, i'm already looking at all sorts of upgrades to do...

[halygon]

The downside, i'm already looking at all sorts of upgrades to do...

That's the sickness that many of us have. Check out the "upgrade" threads for some good ideas of how to approach it.

[allyeajackvk2]

its making a clicking noise? If it is your gonna need to shim your diffs and see if they are stripped

[ThatTraxxas]

its making a clicking noise? If it is your gonna need to shim your diffs and see if they are stripped

It’s just motor cogging, it’s completely normal.

[grizzly03]

Thanks for all the replies. This morning read up and watched a few videos on cogging, could of probably saved me a few hours had i done that initially. But all in all had fun stripping down and being able to put back together the mini and more confident in my abilities. The downside, i'm already looking at all sorts of upgrades to do...

Now you know how to take it apart to add those upgrades!


The best upgrade that I did was to help the handling. Stock (from the factory) the tires wobble because of the pillow ball caps. I installed a set of Traxxas Part #7033x adjustable pivot ball caps. They work just like the ones in the bigger Erevo.

The other upgrade was to the stock steering servo. Mine stripped the gears rather quickly. I replaced mine with a Savox one and have been happy with it.

[ThatTraxxas]

Now you know how to take it apart to add those upgrades!The other upgrade was to the stock steering servo. Mine stripped the gears rather quickly. I replaced mine with a Savox one and have been happy with it.

Agreed, a metal servo is a great upgrade the plastic ones are junk.

[allyeajackvk2]

agreed......