Quote Originally Posted by bluestang67 View Post
I am in agreement with all of the above . Keep working it and it will come . You are making progress so as we say at work don't set em back .

Your shrinking disc looks great , I wonder if the speed is a issue here ?

I just went a read on speed , they recommend 3000 to 6000 for the 9 inch disc and 10,000 to 13,000 rpm for the 4 1/2 disc . He says something of weight on old grinder so applying good pressure must be a technique also .


Q: What speed of grinder do I need for your shrinking discs?
A: For the 9" discs 3000-6000 rpm work great. I personally use an old heavy 6000 rpm grinder. For the 4 1/2"
discs, most small grinders run at 10,000-13,000 rpm. They will work great.


b
Thanks, Bobby! My machine runs 5000rpm, which according to your research, may not be fast enough. I also didn't apply very much pressure. I'll try again with more pressure and see what happens with the speed I have.