Grinder build

J

JBaker

Joined
Nov 11, 2010
Messages
34
So I've been thinking really hard, and I would really like a good grinder (I'd like to build my own, but I doubt it would be any good). So, what I'm thinking is taking a Grizzly bench grinder that I have and purchasing a KMG without a motor. I say KMG because I worked with it over the summer, and I really liked it. The grinder I have has 1/3 HP, 3,450 RPM, and 110 volt motor. My main concern right now is this, does the grinder have enough horse power for knifemaking, and how hard would it be to add the KMG shell to my grinder? I'm pretty sure it would work, but most of the grinders I looked at had at least 1 HP.
What do you guys think?
Thanks for the advice!
 
putting a 1/3 hp motor on a KMG would be like putting a minibike engine on a Harley.
 
AVigil - That cracked me up.

Before I read it I was thinking about some of the GREAT deals I've gotten on motors over the years and that a 2 hp 3 phase variable speed would be the way to go for a couple hundred $. While I have a Leeson 1.5 hp DC on my Bader if I were starting new I'd go for 2 hp.

I realize money can be an issue for many of us, so the exchange here at BladeForums, Craigslist and estate sales are possible ways to save some serious cash if you get a little lucky.

Corey "synthesist" Gimbel
 
My first KMG was a variable speed setup with a 1.5 HP leeson. It was, and still is drastically under-powered. Anything under 30% on the speed controller could be stalled out with even the slightest of pressure. I ended up running it wide open most of the time which basically made the $400 VFD a very expensive on off switch.

I got another KMG and this time went with 3HP 3 phase Leeson with a VFD and its a night and day difference. I would even suggest getting more HP if you can. I like grinding slow with alot of pressure on ceramic belts and I can still stall out the 3HP motor pretty easily at lower speeds. Bigger motors aren't that expensive and can be found pretty easily. I got the motor for dirt cheap off the big auction site. If you shop around you'll find some good deals. A good motor will last 20 years and is worth every penny. Its one of those things that can save you untold hours of frustration and will make your knifemaking experience that much better. Just keep in mind more power is always better. Get at least a 3HP motor and go with a 5 if you can get it, but only if you have a VFD of course. Save up and buy a quality motor and VFD and don't look back.
 
Dirt cheap by some standards, is not dirt cheap by others... if you look on flea-bay you'll find motors at various prices, and while some of them are good deals I wouldn't call them dirt cheap... Of course I'm as cheap a bastard as they come so take it all with a grain or two, ya know?
 
As a reference I built my own no weld grinder and used a 1hp 1750 rpm motor. It is underpowered to the point that I can almost stall it against the platen when hogging 1/4 inch stock. I am currently looking to step up to at least a 2hp 3 phase now.
 
I built a GIB and got my motor from Wayne Coe. It is an Elektrimax 1.5hp single phase. I set my grinder up to run pulleys and it grinds steel with ease and bogging down is never a problem.

The only time it has bogged is when grinding 1/2 thick aluminum which can be grippy on the belt or really large pieces for things not related to make a knife.

If a person only has 115 they are pretty much limited to 1.5hp. Those who have 220v can run 2hp and up.

Oh and I will say if the motor dies I can drop in a new motor easily. If it had a VFD and if anything went wrong with it I would not be able to make knives until someone somewhere could repair the VFD and who knows how long and how much that $$$.



 
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Thanks for the good advice, I was hoping I'd get a different answer, but I guess I'm back to saving for a good one! Thanks again!
 
I agree with AVigil (beautiful grinder build by the way). I have a VFD and I love it but it's expensive and if I didn't have the money right away I'd get a 1.5hp with pulleys or maybe even without pulleys. Later I'd upgrade and use the 1.5 for a disc grinder or something. I love being able to turn down the speed but I actually rarely do it. In fact the best feature to me of the VFD is that I can run the motor FASTER than it's intended.
 
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