I am looking at grinders to sharpen stuff including lathe chisels.
Most books/resources suggest the bigger the wheel the better say 8-10 inch by 3/4-1 inch wide.
I heard some cases that it may be best to go with a variable speed
2000-3450 rpm or a slower one (about 1750 rpm) grinder for more control and or less chance of burn.The dilemma is that I can get a 8" grinder pretty cheap (40.00 with the rough wheels) and wondering which is better to go with, bigger and faster or smaller, but more control. Variable speed @ 6" is about double the price in canada (but it comes with one cool wheel) and going to an 8" variable speed is about 3x, so if I can make an informed decision, it would be great. Sure, I can buy the 8" variable and cover all the bases but why spend more if I can meet my needs with cheaper.
I also heard that even running cool wheels (white ones), it should run at 3450 high speed for the wheel to break off its top layer and stay sharp.
Any thoughts/resources would be very welcom