Converting a KMG to direct drive...?

I would really like to add a second slot to my kmg. It looks like you just need some 1/2in pieces, drill through them lengthwise, and then get longer bolts for the doubled length. Am I correct? Any advice on adding the second slot? Knowing my luck the hole I'll drill will be off centered and the whole dang thing won't line up lol.
 
The top piece needs to be rebated about .035" so that there's sufficient clearance for the tool arm. If you look carefully at the bottom plate on your existing tool slot, you'll see what I'm talking about. It's yet another thing I don't understand about Beaumont. He HAS these parts. They're already what he uses!!! Why the hell wouldn't he offer this as an option...? And yes, you need longer bolts. Can't remember off hand how long I got, but this is basic math.

Larry, grinding sitting down makes a lot of sense. Because I'm using my whole body, I get tired much more quickly, I'm sure. Your grinding rest is similar to one I've seen RJ Martin use. He doesn't rest the blade on it, but rests his hands or fingers on it to assist in smooth grinds.

I was self-taught, as well. Really, what I managed to do for the first two years was develop bad habits until I got the chance to watch someone who knew what they were doing, doing it right!

Also, I post with a certain amount of frequency in the Custom And Handmade Knives area. Probably post more there than I do, here.

Forgot to mention one other critical modification I made on my KMG, but should be obvious in the photos. The tool arm locking screw holes are on the RIGHT side, and there's three holes per tool arm slot, so if a locking screw needs to be moved, it can be. This way, you use your left hand to remove tension from the arm, change your belt, adjust the tool arm with your right hand and lock it down again, without ever reaching around the machine.
 
Matthew, from your photo angles and taking a real super quick look at my KMG i think it is possible to move your mount forward one set of holes, yes/no? that would give you more belt to work with and your tool arm would clear the motor. I've been watching this thread and agree with your assessment of the KMG BTW. I just havent got off my backside to do the mods you have yet. but moving the motor forward seems like it would give you more belt space but also change the belt angle in the back drive wheel to tracking wheel so the sparks that wrap around the wheels does not hit you in the face....look at the angle on a Bader or Esteem...What I have also played with is maximum drive wheel diameter. This lets you use a 1750 rpm motor that has a pile of torque get the sfm of the belts up. Hope I typed this so it makes sense...But the motor mount looks perfect, very nice welds and very good machining.
 
Looks good Matthew!

The direct drive is one of the reasons I like the Bader BIII better than the KMG.
But I really have no complaints with the belt drive on the one KMG we have here.
 
Hey Mike!

What we could have done was replace the back plate which this setup is mounted to, and that would have provided for what you're thinking, I think.;) The theory behind what we elected to do, though, was to make a 'bolt-on' modification, so folks didn't need to disassemble anything except the pulley assembly. The plate we used to mount the motor is oversize, as well, as I was hoping to use an even larger drive wheel I had (7-1/4"), but it was too big and didn't have the appropriate positive offset.

If I get enough interest in this setup, I'll bet I could get him to make a handful. If anyone is interested, PM me or email me - mgregoryknives@yahoo.com.


Don, thanks bud! Agreed on all fronts. Had things worked out differently, I'd own a Bader or one of the other new grinders out there. My experiences with Beaumont have, unfortunately, not been particularly happy ones, which stands in stark contrast to my experiences with the folks at Bader. I feel guilty not supporting someone that's been so good to me, and even worse, I am rewarding someone that's treated me poorly, all because the right deal happened...




mike malosh said:
Matthew, from your photo angles and taking a real super quick look at my KMG i think it is possible to move your mount forward one set of holes, yes/no? that would give you more belt to work with and your tool arm would clear the motor. I've been watching this thread and agree with your assessment of the KMG BTW. I just havent got off my backside to do the mods you have yet. but moving the motor forward seems like it would give you more belt space but also change the belt angle in the back drive wheel to tracking wheel so the sparks that wrap around the wheels does not hit you in the face....look at the angle on a Bader or Esteem...What I have also played with is maximum drive wheel diameter. This lets you use a 1750 rpm motor that has a pile of torque get the sfm of the belts up. Hope I typed this so it makes sense...But the motor mount looks perfect, very nice welds and very good machining.
Click to expand...
 
Matthew Gregory said:
Don, thanks bud! Agreed on all fronts. Had things worked out differently, I'd own a Bader or one of the other new grinders out there. My experiences with Beaumont have, unfortunately, not been particularly happy ones, which stands in stark contrast to my experiences with the folks at Bader. I feel guilty not supporting someone that's been so good to me, and even worse, I am rewarding someone that's treated me poorly, all because the right deal happened...
Click to expand...

Understood. I have two BIIIs' that are used daily, one since 1998. I gave the KMG to my son. ;)
 
Ran this machine quite a bit this week. Absolutely a dream. Runs the way I expect it should!! Quiet, smooth, powerful...

SO glad I did this!!!!

Every aspect of the machine is improved. Finally!!!
 
Looks awesome Matt, if he decides to make more I may be interested, if not, I may have to make my own, as I do have the tools to do so now in my workshop, what I lack is time =)

I have been looking at making a way to flip the KMG to horozotal vs vertical, and the primary issue with doing that is the lack of direct drive motor.

I'm also looking at fabricating a new stand for mine too, with motor + kmg etc, it's heavier than the table I've got it on currently really wants to support in a stable manner.
 
Matthew Gregory said:
The top piece needs to be rebated about .035" so that there's sufficient clearance for the tool arm. If you look carefully at the bottom plate on your existing tool slot, you'll see what I'm talking about. It's yet another thing I don't understand about Beaumont. He HAS these parts. They're already what he uses!!! Why the hell wouldn't he offer this as an option...? And yes, you need longer bolts. Can't remember off hand how long I got, but this is basic math.
Click to expand...

Now if I can just get Rob to answer the phone or email I sent him. I'll probably just end up doing it myself and buy extra steel, thanks for the info.
 
Matthew, I'm glad you finally got your grinder to perform well. I bet all the planning and the work was worth it . Good for you. Now the knives will be flying off your grinder like magic. That direct drive conversion plate was really cool. Just one question... why did the plate have so many holes in it? I'm just curious. Larry
 
Larry, we were trying to make sure this would work for folks with ANY 56C face mount motor, not just mine, so we added 4 additional holes to allow for clocking the motor to make sure the motor's wiring enclosure wouldn't interfere. Saying that likely answers Justin's question a bit, too. :)

If you're interested in one of these setups, email me at and I'll see if I can talk my friend Joe into making a handful of them. Drop me a line, Justin!


JG, if you can drill holes squarely, you can likely do this modification. It's really not a big deal, it's cheap to do, and doesn't take much with the possible exception of the milling work. You'll need some 1-1/2" and 2-1/2" wide pieces of 1/2" cold rolled stock, and some longer bolts. the key is drilling the upright holes accurately and squarely, and removing that bit of steel to allow the arm to slide in. All good!
 
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Any news on the adaptor plates. I'm considering just removing the rear plates that hold the drive shaft and bolting the motor to the table. I run a link belt and I'm getting done with the vibration and slipping. If I could flip the grinder sideways after this mod I would be tickled pink.
 
Hey JT, my buddy isn't making a production run or anything - really, just to order, so if you're interested in one, shoot me an email

One word of note - this kit only bolts to the holes of the upright where the pulleys were mounted. If you're planning on making your grinder vertical/horizontal, you will likely need to drill and tap another couple holes in this as well as the baseplate for your grinder. I have no intention of doing that mod, so we didn't engineer it into the equation. Shouldn't be a big deal for you to do it, though...
 
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What RPM is your motor, mine is 1720 but has a VFD and is over driving the motor up to 9000 SFPM. I have been fighting vibration at high SFPM sence I built this KMG clone. It so bad that the tracking adjusts it's self. At anything over 3k
 
JT, how are you coming up with 9000 sfpm? Assuming your calculations are correct, I've got to wonder how many belts are even capable of that kind of speed...

My motor is 1725, VFD is jumped to 2x, and the drive wheel is 5.5".
 
...you'd need a 9" drive wheel AND a 3:1 pulley ratio in conjunction with your VFD running 2x mode to get that kind of speed. What the heck are you doing , man? :D
 
Here is my setup. I programmed the vfd to show SFPM.

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Face palm, I just saw my motor says 2-1.5HP. M vfd is running on 110 and set for 1.5HP. If I wire 220 I get an extra .5 horse. Man it's just like chrismass lol
 
Jt, If you put a little larger pulley on your jackshaft it will slow your speed down substantially and give you more torque and the ability to run your grinder at a slower speed with more power. I run mine at 4500 SFM and it grinds just fine at top speed. You may like the super fast speed though like the guy from Entrek knives. Most guys like 5000 SFM or a little less for a top speed. Larry
 
Wife had to rip me out of the shop I was rewriting it for 220 lol. I normaly sit around 3-5k when doing edge bevels but when profiling I rotate the 8" contact wheel into position and set up the rest and crank it to 9k. It's my vfd it will go up to 240hz I have it limited to 9000sfpm even though I could go higher. But even warn blaze belts scream at 9k. word of caution, a belt going 9k and snaps is not fun. The other day I put a 50 grit on the grinder and flipped it on and cranked to 9k I turned to grab a blank and the vibration adjusted the tracking wheel and right as I turned around that belt shot off like a rocket. Shot across the shop and up the forge bench. Hits the rafters and shoots right back at me. If your having a hard time with the math 9000 SFPM is over 100 mph.
 
I just noticed, what do you guys do about the motor blocking the tool arms path. I would just couple the motor the the jack shaft. But then I could not flip the grinder on its side. I could build some riser blocks and lift the grinder up a little. Just enough for the tool arm to clear the motor.

In taking thoes pictures I als noticed somthing else my link belt had stretched so the motor was setting on the plywood. I removed one link and now I got tension back facepalm.
 
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