Home Forums Gear Knives and Blades Building a grinder

I intend to build a belt grinder for knifemaking. I plan to use a 1 HP motor and probably a pair of 4-step pulleys; 2,3,4 and 5". My question is, what is the "correct" motor RPM to use, 1725 or 3450, and subsequently a 4 or 6" drive wheel to get the optimal belt speed range?
Thanks in advance!

I found a couple active threads on another forum that address my questions. If anybody is interested:

http://www.bladeforums.com/forums/showthread.php/913576-Which-motor-for-my-no-weld-grinder

http://www.bladeforums.com/forums/showthread.php/913426-Grinder-motor-horsepower

I have done alot of study on this subject, and conclude after talking to alot of people that it the long run you are better off saving up a bit of money and going with the variable speed controllers right off the bat.

Also, most people who have built them have told me not to use less than a 2 horse motor if you can afford it. Again, it might be better to save up a bit of money first and get the motor you will be happy with in the long run.

After talking to a lot of folks, the consensus that I have is that to make a real good machine doesnt' save you a whole lot of money over say something like the KMG machine. Its the large contact wheels that kill you in price.

Thanks for the input.
It's going to be more than I really wanted to invest but the wheels (pun intended) are already in motion. I have the steel for a baseplate and I have a source for some square tubing WAY, WAY below market .
I can weld so that's not a problem.
I have feelers out for used motors but no luck so far. I've been eyeing a 2 horse Grizzly online. They are far less expensive than any other new motor I've seen, and I've not heard any negative.
I'm also working on a MDF contact wheel (14") as per another thread here on the 'fire.
All that being said, I'm not willing at this point to double or triple my cost for a VFD. I'll start with a pair of 3-step pulleys and a wooden wheel, then upgrade if need be.
If one had to pay market prices for steel and didn't do their own welding, then pay full price for contact wheels , I agree that it would be counter-productive to try to build a grinder.
No matter which option you choose, it takes a BUNCH of knives at $.50 profit (or loss) to justify!!