Possible slipper idea?? - RC-Monster Forums

jhautz · 10.24.2006, 01:15 PM

Why couldn't you just mount a typical 3 shoe nitro clutch on the shaft of the motor. You woulnd need an adaptor of some sort, but sesides not being able to use the motor to brake, what is wrong with just using a standard nitro clutch?

BrianG · 10.24.2006, 03:33 PM

I don't think a standard shoe clutch design would work well for two reasons:

1) The clutch engages only at a certain rpm to allow the engine to idle without stalling. We don't need that with electric for obvious reasons. Another function of the clutch is to allow engine rpms to rise enough where it develops some usable power. Again, this isn't needed for electric.

2) The centrifugal force pushes the shoes into the bell harder and harder as rpms increase effectively locking it. High rpms is where you want the protection. The stock setup will grip the hardest at the high rpms and will offer virtually no slip. I wanted a slipper with an even amount of slip no matter what rpm it is spinning at.

Flipping the diff and mounting CB in the standard way sounds like the best idea so far. I'll work on a V2 when I get home and post the result.

Thanks for the feedback guys!

BrianG · 10.25.2006, 10:35 PM

OK, here's the same basic idea with the CB facing the "right" way. I didn't touch this up in PSP though, it's just a direct Excel screenshot (OK, I was lazy). This one is nicer in that there is not thickness problem, and you can use regular 5X8mm bearings. Securing the motor shaft might be a little hard to go to though - maybe a small hole in the CB to allow an Allen wrench to get in there?

jhautz · 10.25.2006, 11:42 PM

looks better that way. how do you adjust the tention?

jhautz · 10.26.2006, 12:26 AM

What about moving the slipper pad to the flat inner face of the clutch bell and using a conventional spring and nut to adjust slipper tention.

Something like this.

BrianG · 12:36 AM

Quote:

Originally Posted by jhautz

What about moving the slipper pad to the flat inner face of the clutch bell and using a conventional spring and nut to adjust slipper tention.

Something like this.

That looks good, but would there be too much stress on the bearings essentially shearing them apart (the CB pushing out while the hub is being pushed in)?

BTW: I'm glad there are others tying to think of a way to do something like this! It doesn't even have to use a CB; I just decided to try it since I had one on hand for measurements.

jhautz · 12:36 AM

You could make little spacers that would stack up and contact only on the inner ring of the bearing. Esentially makeing a solid column to support the load. Than the balls in the bearing would not take the load.

This was just a rough concept sketch. There would be plenty of details to work out.

I think that something like this could work though.

BrianG · 10.26.2006, 12:28 AM

For the tension, there are spring-loaded screws, probably four in all. The springs are the red dots - remember, it's a cut-away view. The problem with this is you have to have the CB seperate from the hub to adjust the tension, then have to muscle it back in the CB. Then again, you generally don't want too much slip since it's really intended for drivetrain protection so there shouldn't be much adjustment. The screw part could be eliminated, but then there would be nothing to stop the pads from gripping harder at high rpm due to centrifugal force (same problem as with using clutch shoes, mentioned earlier). The springs provide the force, the screws provide the limit.

It's hard to make stuff in Excel (but much faster) so it might not be readily apparent.

This version looks much easier and cheaper to build.