KMG Grinder...is 1 hp motor enough?

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godogs57

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Apr 16, 2004
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Contemplating buying a KMG at the Blade Show. I have a friend who sells industrial motors and just gave me a spank brand new 1 hp GE "farm" motor. Supposedly the farm motor is sort of like an industrial/commercial grade of motor.

I have a Wilton Square wheel grinder now and am looking for another grinder and am not sure how I would hook the motor up to the KMG...may spring for a Baldor and be done with it but am not sure at this time.

Thanks for your opinions.
 
Honestly it will work, but it will be lacking some torque. If you should lay into it you will stall it.......I have a 1.5 and 2 horse on my kmg's and i will be upgrading one to a 3-4 hp.

Just my 2 cents
spencer
 
A grinder can have not enough HP but it is hard to have too much. Get 1.5HP as a minimum, 2HP is better.
Stacy
 
I know this subject has been talked to death; but were talking about::eek::thumbup:
Belt Speed! feet per minute, Torque! I'll pay any price for it.
I love the KMG:cool: but I would like it better running at 4500sfm with 3 horse power at hand. I'll run a four pulley set up on the next one.

You're just not getting your moneys worth, from those expensive ceramic belts, running in the mid 30's

I'm running a 11/2 hp motor on it now . Its adequate:o.

Fred
 
Okay I may not know my proverbial *$$ from a hole in the ground. but I have a 1hp on my kmg and can't say I ever felt I needed more, though I have only had it a short time. I also do not use it to profile I use a disc for that. The 1hp is FREE FREE FREE!!! Use it til you think you need something else.
Matt
 
Industry minimum for belt gringers is 1 hp per 1" of belt width.

My two 1-1/2 hp VS B-lll's are fine with folders and small blades but not close to enough hp for large wide blades. I'm going to talk to Rob at Blade and will add a KMG with a 3-5 hp VFD to my shop soon.
 
I have three grinders in the shop. A 1 hp burr-king- easy to stall. Especially taper tanging. 1.5 Vari Burr-King. Better, but still can stall it. 2 HP non vari. Bader III. It is a hoss. The Burr-Kings are 1725 RPm giving 480 SFPM. The Vari is 2500 RPM, giving 7200 with a 10 wheel. The Bader is 3600 giving 6800 SFPM. I read here in the forums that many makers don't like the faster speeds. Yes it can be a little bit harder to control. But really digs the steel off when doing heavy grinds. Slower speeds never seem to dig in and hog when working with the ceramic. I like to slow things down a bit when using finer belts. A luxury i didn't have for the first 25 years of knife making. Makes a big difference. I would like to try a Kmg with faster belt speed than they are set up for from Rob's. And more HP! Should be fun. I once had a custom Blade Master Grinder built that would go to 10,000 SFPM. Man that thing wails grind! Killed bearings, and my ear's though. Even with shooting muffs on. Wonder what ever happened to Blade Master Grinders. Mike
 
I have a 1-1/2 HP VS on my KMG. I'm 100% with all the guys that want more power :thumbup: I stall mine on a regular basis, especially running at slower speeds. I'm looking for at minimum a 3 HP motor. I plan on using the 1-1/2 on a Beaumont 9" Disk set-up. As stated already, it will work, but you'll want more power too, very soon ;) Guaranteed :)
 
Here's another question:

If a motor can be wired for 110 or 220 volts, which is better? Won't the HP be the same either way?
 
The new AC 1 1/2 hp VS setup on my KMG seems to work just fine, but i know that a lot of folks say that you should go ahead and spring for the 2 hp motor.
 
I think if you would go with one hp on the Bader III then that would be just fine for the KMG. If the Bader is going to have a stronger motor then it's harder to compare. Both nice, I think the better value is with the KMG.
Good luck, Craig
 
David Wesner said:
I have a 1-1/2 HP VS on my KMG. I'm 100% with all the guys that want more power :thumbup: I stall mine on a regular basis, especially running at slower speeds. I'm looking for at minimum a 3 HP motor. I plan on using the 1-1/2 on a Beaumont 9" Disk set-up. As stated already, it will work, but you'll want more power too, very soon ;) Guaranteed :)
Click to expand...
Thats a good go, using the 1 1/2 horse on the disc grinder. I do run a ver.speed. Don't know how I ever did without it.

I use a Beaumont 9 inch. Good wheel. :thumbup:

I'm going to put knew bearings in the kmg before I move up to the higher hp.


Fred
 
Phillip Patton said:
Here's another question:

If a motor can be wired for 110 or 220 volts, which is better? Won't the HP be the same either way?
Click to expand...


Yes, but the amp draw will be double on 110 leg, requiring larger wire. I wouldn't bother with 220 with 1 hp, because amp draw should be around 10 amps or less at 110V, which is no trouble on even 14 ga wire, but you get into a 3 hp/5hp peak motor, you'll be drawig over 4000 watts (like a water heater) which is 36 amps on 110 (big wire), but only 18 amps on 220 (standard 12 ga wire).

The difference is, 110 has a hot leg and a neutral. 220 has two hot legs, so less amps (smaller wire) is required for a given number of watts (hp)
 
mlovett said:
I have three grinders in the shop. A 1 hp burr-king- easy to stall. Especially taper tanging. 1.5 Vari Burr-King. Better, but still can stall it. 2 HP non vari. Bader III. It is a hoss. The Burr-Kings are 1725 RPm giving 480 SFPM. The Vari is 2500 RPM, giving 7200 with a 10 wheel. The Bader is 3600 giving 6800 SFPM. I read here in the forums that many makers don't like the faster speeds. Yes it can be a little bit harder to control. But really digs the steel off when doing heavy grinds. Slower speeds never seem to dig in and hog when working with the ceramic. I like to slow things down a bit when using finer belts. A luxury i didn't have for the first 25 years of knife making. Makes a big difference. I would like to try a Kmg with faster belt speed than they are set up for from Rob's. And more HP! Should be fun. I once had a custom Blade Master Grinder built that would go to 10,000 SFPM. Man that thing wails grind! Killed bearings, and my ear's though. Even with shooting muffs on. Wonder what ever happened to Blade Master Grinders. Mike
Click to expand...

Just wanted to make a point about bearing life. There are two things that reduce a bearings life significantly. One is speed, and the other is load.

If you double a bearings speed, you reduce the life of the bearing by one half.

If you double the load on a bearing (for example, tighten the belts up significantly or push hard when grinding, you reduce the life by a factor of ten!

These statistics assume that you're not overheating the bearings. If you're bearings run hotter than 140 degrees F., then it will effect the lubrication and thus the bearings. For every 18 degrees F. above 140 degrees F., you cut the lubricant life in half, and thus the bearing life in half.

An example would be the following set up.
  • You're getting 5 years bearing life out of your current setup.
  • You change your pulleys to run twice as fast.
  • This also causes your temperature to go up to 158 degrees F. (this is not always the case, but could happen)
  • You're bearing life is 5 years divided by two divided by two.
  • The resutling bearing life is now 1 year and 3 months.
A second example is the following.
  • You're getting the same 5 years bearing life as above with your current setup.
  • You begin making a knife style that causes you to really lean hard and work the motor and bearings, thus doubling the load.
  • This also causes your temperature to go up to 158 degrees F.
  • You're bearing life is now 5 years divided by two divided by ten.
  • The resulting bearing life is now 3 months!
My point is that you should get enough speed on your belts, so that you don't have to work as hard to remove material.

This will help you achieve the best setup for your grinders for both speed and load. At the very least, you'll know how changing your setup will effect the bearings life.

Just a few pointers from your local bearing technical representative. ;)

Scott (Ickie) Ickes
 
Wow...thanks for the replies....I sure do appreciate it.

I am planning on using the second grinder for flat grinding and keeping the Wilton set up for hollow grinding. From what I have heard from everyone, a variable speed control is also the way to go as well....will have to study on this further.

Thanks again for your replies.
 
Thanks Scott! Great Info!!!Now if I could Just figure out how to copy your post without the entire page! Mike
 
Nathan the Machinist said:
Yes, but the amp draw will be double on 110 leg, requiring larger wire. I wouldn't bother with 220 with 1 hp, because amp draw should be around 10 amps or less at 110V, which is no trouble on even 14 ga wire, but you get into a 3 hp/5hp peak motor, you'll be drawig over 4000 watts (like a water heater) which is 36 amps on 110 (big wire), but only 18 amps on 220 (standard 12 ga wire).

The difference is, 110 has a hot leg and a neutral. 220 has two hot legs, so less amps (smaller wire) is required for a given number of watts (hp)
Click to expand...

I made my power cord by cutting off a good sturdy outdoor extension cord that I bought at HD and wired it up myself. Not sure if I could have done that with a 220.
 
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