Hello, we are new to EA, we have built two vehicles that we will be competing in CT, in 2013. We are running into a problem where we are breaking the freewheel device, his is the brass device that spins onto the rim, and has four holes where a sprocket is mounted.
When first installed the device works great, we can get a few miles out of it. After a small test, the device locks up, it will not freewheel anymore, we have even broken one where it will just spin and not turn the wheel. We have broken probably seven so far. Can you maybe tell us what we are doing wrong?
If they are two pawl freewheels, they won't be able to handle the stress and torque will destroy it.
I use a four pawl freewheel in my car. I just had to replace the first one during spring break, it kept sticking so it wouldn't freewheel and it's been on the car for four years.
With the extra pawls in the freewheel, they handle the load better.
Sorry, I didn't think to explain what 'pawls' are. Pawls are the part of the freewheel that 'click' when the car is freewheeling. They have a spring built into each pawl that engages a ridge inside the freewheel. This engages the drive wheel when you put in throttle input to the controller, thus making the motor spin allowing the pawls to engage and make the car move. The more pawls, the less likely the freewheel will break sooner. You can usually check by listening for how many clicks happen each time they engage. Or check with the manufacturare of the freewheel. Or check with Kirk Swaney, I'm sure he would be more than happy to tell you.
we just had the freewheel break at the Emerald Coast Electrathon. We installed it on a 20 inch wheel so that we could increase the velocity of the vehicle. We made the change from a 16 inch wheel that had the disc brake bolt pattern as the mounting setup for our pulley. 10 min into the event it came apart. We will machine an adapter that does not use the freewheel. On the oval banked track the constant velocity algorithm is better and you do not need the freewheel.
i should have mentioned.... we are using the 60tooth sprocket on a 20inch rim for our drive wheel, thats where we keep breaking this freewheel,
our car, because of the steel weighs roughly 220lbs, not including the batteries, plus a driver of 180 plus, rough numbers I think we are pushing in the vicinity of 450-490 lbs.... we are thinkning it must be weight and torque that is doing this, we have about 1/2 inch of chain deflection, and are using #35 chain
our rear tire pressure, is at 75psi, was told to put at 110psi, but it just seemed too much
-- Edited by mikestill on Wednesday 1st of May 2013 07:57:40 PM
