Slipper clutches

[markymark6183]

Hi guys can someone explain to me like I'm a 5 year old how a slipper clutch works please
Thanks in advance

[blue_pinky]

I'll have a go...

Take a look at the spur gear in your car...take it out and look at the hole in the middle of it.

You'll notice it's not keyed in any way to the shaft it sits on. Slide it over the shaft it sits on without the slipper mech attached and you'll see it spins freely!

The output/drive shaft does not get any rotating force from the spur.

So where does the rotating force come from?

The slipper mech! The slipper is made up of a sandwich of plates and slipper pads. The slipper plates on either side ARE keyed to the output/driving shaft, so they rotate with the shaft. When you sandwich the plates, and slipper pads on either sie of the spur, and tighten the spring loaded nut down, your squashing the pads between the spur and plates, and applying a friction force to effectively 'join' the slipper plates to the spur. It's this friction that transfers the rotating force from the spur to the drive shaft...driving the car forward.

You adjust the amount of friction to help match the torque of the motor to the grip level the track has. This helps to reduce wheel spin, and provide a softer feel to the throttle by controlling the amount of drive you can apply to the wheels...on dusty low grip tracks you'd run the slipper loose as the wheels spin more easily on the surface, on high grip tracks you can tighten the slipper as they will tend to spin less, a vital bit of tuning!!!

Typically you adjust the slipper so that it slips for the first few meters from standing start if you nail the throttle. You'll learn to tell the sound of the slipper from the high pitched squeeling noise it gives off when it's loose.

I think that's about right anyway! Hope it helps

[markymark6183]

Blue-pinky that totally makes sence, thankyou buddy much appreciated, I'm just waiting for my lipo to arrive then I can try out my buggy I'm just hoping I've built all the gear section correct but thanks a million

[SlowOne]

Great explanation. Just to add that the reason slippers work as they do is the PTFE plates on either side. PTFE is a material that is able to move from sliding friction to static friction seamlessly. If it didn't, then the diff would lurch from slip to grip, and make teh cars almost undriveable.

I think the idea was pioneered by Losi, and I first saw one at the 1989 Worlds in Sydney, Australia. It was so obviously superior to anything else we did to make a car driveable on the slippery track. IIRC, Cecil Schumacher set about making one for Jamie Booth and Jamie tried it during qualifying. I can't remember whether Jamie used it to get his car into the A final, but I do remember that as one of the most heroic qualifying performances I have ever seen! HTH