KMG Grinder Tweaks Thread

I didn't even remember that thread.

Feel free to shoot me an email or give me a call Tait.

More than willing to help, just don't have the time to build more, or make drawings...
 
The thread was very helpful - mostly I wanted to see how you channeled the water.

Aww man! Just when I thought I was "done" building things to build things....

Well, I'll likely get in touch when I can't figure something out. Thanks!
 
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I mentioned lifting the KMG in the first post here.

Subsequently, I found myself wanting to move the grinder over a bit, but limited by the fairly short cord. Since I had a piece of solid core door laying around that was 18.5x17.5, I realized I could cut it in half and slide the halves apart to make a one inch gap for the cord to pass through. Then I realized by cutting at 75 degrees instead of 90, I could have the cord pass at an angle, which gave me the extra slack I was looking for to move the grinder a little further from the plug.
 
I notice a lot of guys using an extension like Brian mentioned, but the problem I see with this is you have to have a lot of spring travel left.... I don't know if it's on Rob's website or if it was just in private emails between Rob and I, but I know he recommends you have the tension arm setting PARALLEL with the base/workbench when the grinder is running. This means you HAVE to have it pushed way down on that spring. My KMGs track MUCH MUCH better set this way.
 
What am I missing Nick?
I don't see where extending the arm affects anything but the amount of force required to compress the spring.
Doesn't affect the travel of the spring at all, or anything else for that matter.

Everything still works just exactly like it did from Rob, just easier...
Same range of motion on the arm, you just have more leverage to put it through that range of motion...
 
If I can channel Nick for a second (minus the speedo ;)) I think that by extension he meant the water cooled platen.
 
I probably am not wording it right. Oh, and I'm not talking about the water cooled platen at all :)

I'm talking about the idler/tracking wheel arm and grinding belt tension. Rob designed the KMG to operate with extreme belt (the abrasive belt) tension. In order to achieve that, you need the idler/tracking wheel arm to be pushed way down on the spring.... so that the arm sets parallel to the grinder base/workbench.

If you have enough spring left that you can push down on the idler/tracking wheel arm to change belts, then there's not as much compression on the spring (and thus tension on the abrasive belt) as Rob planned on with the design of the grinder.

Here's how most photos I see of KMG's are. Here the idler/tracking wheel arm is up high and there is a lot of travel left in the spring. With an extension it's easy to push this down and change belts. But gave me hit and miss belt tracking. (put a level on the arm for clarity)

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Here is how I run my KMG's. The idler/tracking wheel arm is pushed down hard to put a lot of tension on the grinding belt. The spring is nearly bottomed out, and it wouldn't matter how long your lever was, there isn't enough travel left to push down and release the belt---you've got to move the tooling arm.
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I'm not saying this is right and everybody else is wrong, but it has proven to give me much better tracking.... and I didn't start doing it this way until talking to Rob about tracking issues on a friend's KMG.
 
You are absolutely right Nick, the KMG tracks best when the arm is horizontal like that.
The tracking wheels axis of movement is where it is supposed to be for best results.

However, more leverage, (a longer arm) just makes it easier to get the arm in that position.
It doesn't affect the ability of the arm to get there, just the energy required to do so.

This makes a difference when you have flimsy little girly arms like me!
 
Fellhoelter said:
However, more leverage, (a longer arm) just makes it easier to get the arm in that position.
It doesn't affect the ability of the arm to get there, just the energy required to do so.
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That's exactly what I thought. That's why I mentioned the platen since what Nick said didn't makes sense. :confused::confused::confused:
It did make me realize that I probably run my belts too slack. Thanks.:thumbup:
 
Patrice Lemée;9533822 said:
That's exactly what I thought. That's why I mentioned the platen since what Nick said didn't makes sense. :confused::confused::confused:
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Hey, just because I don't speak Canadian....!!!

We're on the same page then Brian------since I push the idler/tracking wheel arm down all the way and have to move the tooling arm, I like having both hands close to the same area to push the arm down and lock the ratcheting lever. This is probably just further proof I need to get my ass back in shape if I can just lean on that spring and smoosh it. ;) LOL
 
Mechanical advantage is your friend !

I also moved my ratcheting lever to the other side.

My left hand compresses while my right hand puts the arm where I want it.
Once the arm is there, the right hand is free to lighten the lever.

You need to do some modifying if you have to move the arm in and out for every belt change.
That's retarded.

At least with the system on yours, you can adjust the spring to get more stroke.
You may have to get a longer spring, but you can adjust the stop, giving you enough range of motion to allow for belt changes.

My spring rests on a fixed spacer.
 
Hey guys, I just set up my first kmg grinder and I noticed a bumping feel to it when I just the platen attachment, it almost feels like it's where the belt is taped together. Do any of you guys know of any adjustments that I might need to make?

Thanks,
T M
 
Someone advise filing down the abrasive on the splice to both minimizing the "bump" and making it non-cutting, to improve the finish.
 
Here are my tweaks for the kmg; Extend the tracking arm handle and install a 30 or 40 lb gas piston. Use a 4 inch crowned tracking wheel. tighten and lubricate the tracking arm pivot so it has no play but smoothly travels, and make all toolbars from aircraft aluminum and drill and tap in a mill for perfect perpendicularity. Use .043 machine bushings to line up the contact wheel , drive wheel, and tracking wheel perfectly.
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I spoke with someone earlier today about alignment issues on my new KMG-1. So after wiring and setting up I had an alignment issue which still is a bit finicky depending on what belt I have on there. The whole set up is mounted on the KMG Plate.
Now it seems like the other issue I'm having is with the 1 1/2hp motor. Sometimes it sounds like it's overloaded or struggling and won't spin. This is without even grinding anything. If it stays like this too long it will trip the breaker.
I tried to adjust the length and drive belt tension but nothing seems to work. I know the drive belt isn't crazy tight but it certainly isn't loose either.
Also if I changed grinding belts it's like the whole grinder needs to be readjusted. I'm not overloading the work arm with crazy tension either and i feel like if I did the motor certainly won't spin. I find it very hard to believe that this grinder can actually be this finicky and I purchased it because of its stellar reputation. If you have any advice I really appreciate it.
 
Snpr9696, Are you using a VFD to control the speed? There are some adjustments that have to be made to the drive when setting it up. If not then you have a wiring or a motor problem. Where did the motor come from and what are its specs? A 1 1/2 hp motor should run the KMG well. Something major is wrong. More information and maybe a photo would help. Larry
 
snpr9696 said:
Now it seems like the other issue I'm having is with the 1 1/2hp motor. Sometimes it sounds like it's overloaded or struggling and won't spin. This is without even grinding anything. If it stays like this too long it will trip the breaker.
Click to expand...

By any chance are you running on an extension cord or small power bar? If so, that's likely your problem.

Mine was doing the same thing while running on a 25 foot extension cord or if I had it plugged into a power bar. I moved the grinder to where I could plug directly into a 15 amp outlet and my problems completely went away.
 
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