Thread: Belt grinder speed

Hi all!

I am going to build a 2x72" all purpose belt grinder, mainly for making razors, knives, and restorating razors. My main question would be, what surface speed should I run? I will use a step pulley, so I will have 3 speeds to use, so I can play a bit with it.

What is the minimum I need for roughing? What is the maximum I can use when finish grinding? Some guide lines would be good to start with.

BTW the motor is a 750W 2 phase with 2870RPM, I hope this will fit the bill.
I have some motors that are in the 150-200W range, those run about 3000RPM, have these enough power to make a small belt grinder solely for resto work? I don't think they are suited for bigger grinding projects, but maybe I am wrong, this is why I am asking

How many horse-power is that? I wouldn't recommend much smaller than 1 hp for a 2x72. I would slow it down with as small a pulley as you can on the motor and go a bit larger on the drive wheel/shaft. Then you have the size of the drive wheel to keep in mind. Key thing is that you can slow it down enough to keep the heat from the friction down once you heat treat your blade...no matter if a knife or razor. Then if you could speed it up a bit for "hogging out" material if you are using the "stock removal" method it would be nice. If I were to have to choose, I would choose slower over faster. Less chances for an OOPS that way.

750W is exactly 1HP. I have a 2 phase slow motor too, that is 1HP and turns at 690RPM, and one 3 phase that is 1,5HP and 1440RPM. If I look around in the garage I will find maybe more, thats why it would be good to know how much SFPM I should be looking at. Slower speed is better for me too, I don't like to go too fast. My step pulley allows me about 50% speed difference between the biggest and the smallest wheel.

If the two motors that are 2 phase have the same shaft diameter, you can just see which one works the best. There is a thread or two somewhere referencing the SFPM, but I don't know them. It would be real nice if you could make a way so you could use the fast motor for rough work and the slow motor for final work or after heat treatment. If you were to have a simple "plug in" on the motor and had the motor on a pivot point that the weight of the motor kept the belt tight, I'm sure you could make a "quick change" set up simply by unplugging, lifting the motor, taking off belt, and lifting the motor off & replacing with the other one. I hope this makes since. Here is some links to member "spazola" setup showing something like I am talking about for the "quick change" motor...maybe the pics will help.

http://straightrazorpalace.com/forge...er-v2-0-a.html

some other good stuff by him:
http://straightrazorpalace.com/forge...fer-setup.html