KMG converted to direct drive!

EdCaffreyMS

EdCaffreyMS

"The Montana Bladesmith"
Gave the old girl a brand new lease on life! Actually pretty simple, after Matt shared the images of his conversion. I personally like the rubber covered drive wheel better then a solid metal wheel...... less slip on the belt. All I can say is there is a HUGE difference in how the machine grinds and feels versus the belt drive.

Essentially all I did was remove the to "stanchions" that held the pillow blocks, drive shaft, and pulley, and using the existing bolt holes and bolts, drilled and threaded the new motor adapter plate, and simply bolted it to the KMG's frame...... you just have to be cautious of the spacing to ensure you can align all the wheels when the motor is in place/new drive wheel is installed.

The motor I chose is: http://www.electricmotorwholesale.com/LEESON-113890/ I've been buying motors and controllers from these folks for several years.... they always seem to have the best prices, and are very helpful when you need tech support/advice.





 
Does the tool arm hit the motor?
Click to expand...

Good catch! I forgot to mention that...... in my case, with certain attachments it does! I solved it by simply trimming the length of the tooling arm to a length that would work with ALL my attachments.

Also, as soon as I get the time, I'll build a tutorial on how I used a single KBAC VFD to power TWO separate grinders. Just by buying/wiring in a toggle switch, you can run two machine off one VFD..... and save about $400 in the process.
 
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Rather than go to the trouble to make the brackets just mount the motor, using the feet to the base, or table. I lay a framing square along the grinder frame with the short let along the motor foot. If it winds up not being exactly square because of miss drilling you probably have enough adjustment by loosening the foot mount bolts and shifting the motor a little. I have been advising this for about 5 years now for KMGs or other similar situations. As I have said numerous times, you will be amazed at how much smoother and quieter the grinder will run and how much more power you will have.
If the tool arm interference is a problem you can always raise the grinder frame the needed amount.

Let me know if I can help you.
 
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Jaxxas: Beaumount Metalwork (Rob Frink), offers the rubber coated drive wheel. I've been using them for a few years now, and far prefer them to the solid aluminum drive wheels. Much quieter, and far less belt slippage.

Wayne: I'm not following what you are talking about.... on the KMGs I own, there isn't enough room on the KMG base to mount a base type motor, and even if there was, there's no way you could get at the front bolt of the motor base. "Different strokes" I suppose, but I personally don't like the idea of mounting the motor to the bench, or "separate" from the machine.... just too many variables to get "right". Yes, the mounting plate for the motor (in my case a 56C frame mount) can be a pain to make, but the only two things you need to get right when mounting is to ensure that the mount is put together at 90 degrees, and when the motor mount is attached to the KMG, the spacing of the drive wheel is correct. Otherwise its very simple to use a transfer punch to mark the holes, drill/tap them, and use the existing KMG bolts to attach the motor mount to the KMG frame. Here's a pic to illustrate what I'm talking about.

When it comes to raising the grinder frame for tooling arm clearance, I have to respectfully disagree with that idea.... a grinder needs to be mounted at a specific height for it's user. Raising or lowering the height of a grinder just a few inches up or down from where it needs to be, can cause serious grinding issues. To some, that might not make sense, but for anyone who's been to my shop for classes, I always teach that a grinder's height is critical to the ease or difficulty of learning to grind. Any time a person has to "reach", whether that be up or down, it has serious negative impacts on grinding. If you notice in the pic below, I had to raise the KMG a bit to be "right" for me (had to add 2x4s under the grinder). In reality, having to raise a grinder isn't hard, but having to lower one is a pain. The grinder the sits next to the KMG had to be lowered about 3" to be at the correct height for me....which meant I had to lower that entire portion of the bench's top...... UGH! :)
 
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By the way..... I'd be remiss if I didn't offer a big THANK YOU to Matthew for posting pics of his KMG conversion. Although I'd been considering the conversion for a while, his post/pics are what finally got me off my duff, and into action. Honestly, my intent was to wait for a bit of "slack time" in the shop, but my old KMG motor bit the dust about mid week (and I had a student in the shop), so it forced me to burn the midnight oil and get the conversion done, so we could use the grinder during the rest of the class. :)
 
EdCaffreyMS said:
Jaxxas: Beaumount Metalwork (Rob Frink), offers the rubber coated drive wheel. I've been using them for a few years now, and far prefer them to the solid aluminum drive wheels. Much quieter, and far less belt slippage.
Click to expand...

Thanks Ed, it is ordered!
 
I've not found them in anything bigger then 4"..... in fact Beaumont is the ONLY place I've found them. With the new setup, even 100% on the VFD (mine's set at double speed too) seems a bit slow compared to the old moter/controller with the Vbelt & pulleys. There we go...... just one more example of that "give-n-take" thing that I'm always talking about! :)
 
Ed, perhaps I missed it but what did you do about the shaft length on the motor? Was there enough shaft to engage the drive wheel sufficiently?

I'm on a terrible connection and couldn't get the link to open so I could read your motor specs.


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John...... the standard motor shaft was plenty long enough for the conversion....in fact my initial intent was to make the motor's face plate even with the outside edge of the KMG frame.....but that would have made the drive wheel set too far out.... I had to move the motor faceplate about 1/2" inside the frame to get the drive wheel far enough inward to align everything.

And of course when I was tightening the drive wheel set screw, what do I do? SNAPPED the end of the hex wrench off inside the set screw......guess it's there forever now. :)
 
HAHA! I've had days like that!

Thanks for the great description. That's great to know about the shaft length being good to go. This conversion sounds like a winner.


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:) I think your right. It always seems that when I purchase a new machine, or even "upgrade" an older one, I have to do some "tweaking" to make it do what I want it to. Its generally about making it more user friendly for me, or making the machine perform more efficiently, with less maintenance. I guess it could all be summed up as "personalizing" :)
 
Ed, do you use any horizontal grinders at all? with the direct drive would it be very hard to turn the KMG into a horizontal grinder aswell?
 
Matthew Gregory said:
I have concerns about the length of the shaft. Placing constant tension against the outer length of that shaft is placing stress on the bearings. Can't be sure it'll be a problem, of course, but a properly designed drive wheel eliminates that worry entirely. The 5.5" wheel my friend Joe is making for these kits isn't covered in rubber, but I've yet to get a belt to slip on mine. Perhaps my style of grinding is just different, though. He does, however, use an offset that utilizes the entire bearing surface of the shaft so it's not acting so much like a lever. As I mentioned, though, I really don't know how much of a concern this is.
Frankly, Ed, I'm kind of surprised I didn't hear from you about the conversion kit. He sells the whole deal, drive wheel and all, for $240 shipped. I've had machinists order the kit from me because they said it was cheaper than if they made it themselves! ;)
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Matt, with the new direct drive change, would you go with a KMG again? How well do you like the extra tooling arm?
 
Matthew: I THOUGHT I was gona order it..... but I mentioned it to a friend on mine, who ask me which motor I was going to use, so I told him. Next thing I knew he was walking in the shop door with the adapter plate. It took me all of 20 mins to drill/tap the holes on a piece of 1/2" plate for mounting it to the KMG....and it was ready to go. :) After having used the rubber covered drive wheel on my other machines for a couple of years, I also knew that was the way I wanted to go.....so for me, the solid drive wheel would have been a waste of money. It was just blind luck that it all worked out the way it did.

Daniel: I don't have/use any horizontal grinders.... I've just never seen the need for one (for me). That being said, I think it would be fairly simple to put some type of hinge mechanism on the KMG base plate...and provided you consider the necessary clearance for the motor sticking out, it should be an easy job.
 
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Matt check with Chris at Wilmont grinders. My LB1000 came with a 5" I believe rubber coated drive wheel. If you look up the LB1000 on his website you can see the one Im talking about but he does not list it on his accessories link, might just take a phone call to get one.

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This is definitely a genius move, with no drawbacks that I can see. I'm quite surprised Rob doesn't start offering his option for his variable packages.

Couple that with a hinged plate and a secondary tool arm and he'd be cooking with gas.
 
Matthew's post EXACTLY right. We each come at things through the lens of our own experiences, and what works for one person, does not necessarily work the same for another person. I feel bad that you (Matthew) have had less then positive experiences with Beaumont and the KMG..... all of my dealings/experiences have been stellar.

A perfect example of how different makers differ on equipment is the mention of the TW-90. I've used several of them, and FOR ME, there are so many things that are "wrong" with that machine, that I could never see spending that much money on it. However, that doesn't mean that another maker wouldn't find it to be their "dream" machine.
 
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