Post by scooter on Feb 7, 2015 19:15:09 GMT -5
I finally got to try some shims out today.
I put 1/2mm of shims (2 shims) in between the boss and the drive face and the low end shuddering went way down. I added two more shims and the shuddering has almost stopped. It has little to no shudder on take off. It's very faint, not at all like it was.
On the top end I lost 5 mph, down to 65. I expected this because I was already able to wind out the motor without the shims, so I was not trying to overcome a low rpm issue like RCQ is. In his case, he may gain top end as well as acceleration.
I am pretty sure that my variator is too tight at the bottom, and possibly slightly out of square, and that it needs to be shaved from zero at the top, down to .020" or so at the bottom, on both sides, or .040 on one side, depending on which sheave or both is off angle. That will make the shuddering go away, keep my good low end acceleration, and keep my 70mph top end speed.
For now the setup is fine. I am going to ride it, get an indicator and test it and the drive shaft, then I may take it to a machine shop, but I really don't know any local machinists so I'm concerned they might mess it up. Not every machinist knows how to do delicate and exacting work. They could end up ruining it if they don't get how sensitive these units are to being the correct size and angle.
The sad part is that the old worn variator works great and this new one stinks. I may just use the old one if I can't get this one machined cheaply. It may be time for me to start looking for a lathe for my shop. One of those combo lathe/mill machines might be nice. Not as nice as a big shop lathe and mill, but maybe good enough for scooter parts.
I hope RCQ will try the shims. He has nothing to lose by doing it and I'd like to hear the results. I think if he can get his rpms up, he may be able to go faster.
