Originally posted by NOCARRIER
I think I have an idea of your explination of a cam grinder.
Am i correct in saying that it works somewhat similar to a key copying machine?
But instead of cutting flat keys, the stock it is rotated on one side which is directly connected to another part of the machine that, when turns causes the cam portion to rotate under the grinder.
With an eccentric to cause the grinder to "rise" and "fall" onto the stock you are grinding.
How do you design the geometry of the eccentric to cut the journal?
Super cool stuff !!!!!
I guess that after you design the eccentric all you got to do is flip 180 degrees for intake and exhaut. |
Oh yeah! A key cutter machine is the basic concept. I guess you figured out what I meant after all!
On the lathe, turn the basic cam and the maximum diameter of the lobes, then grind the profile.
The distance between the pivot shaft and the profile (cam) shaft sets the 'scale' of the final part. For instance, you can changed the location of the pattern shaft to get 1:1 or 1:2 or 1:4 motion.
I planned to get an old cam of something (or use one of my new race cams for my race car) to establish a profile. If you want to get really fancy, just do the profile in cad, use your CNC mill to route out the profile in some .250 or so thick stock, and mount it on the grinder shaft with a set screw. By marking it and using a dial wheel, you can simply loosen it up on the shaft and rotate it to the next spot to cut the next cam lobe.
Cheers,
Dave.