Belt Wobble / Grinder Set Up

CDHumiston

CDHumiston

KNIFE MAKER
I have been having some trouble with belt wobble on my KMG. It happens with every belt I have so I'm sure it's not the belts. I don't think there is anything actually wrong with the grinder, I think I may have something aligned wrong.

Can anyone shed some light on exactly how they set up the belts, wheels, pulleys, etc. on thier grinders.

Thanks,
 
I have the same problem I think I miss aligned a bolt I am going to barrow a alignment gage from work one that has a magnet with a pin that registers any change in distance as you turn the wheel. Mine is not real bad just enough to see and feel.
 
My homebuilt grinder had belt wander. It turned out to be a lack of tension. I thought it was fine until I used a Bader.
 
tighter on the belt tension works half of the time of the time.
 
As Tracy said...most belt wobble is due to a lack of tension on the belt.

In some cases there are issues with the belts themselves. Old belts that hand around in humid environments will "warp", and sometimes belts, it seems more and more these days, will come from the factory that have not been cut true.

I've had to return several orders of "Blaze" belts to Tru-Grit in the past year because the belts were obviously not cut straight when they were made.
 
Assuming your grinder has step pulleys:
1. I lay a straight edge from one pulley to the other and make sure they are in line, no light gap between the straight edge and the pulley anywhere.
2. Next I lay the straight edge on the side of the 8" wheel with no light anywhere and make sure that it lines up with the drive wheel. The drive wheel is about a half inch wider than the 2" contact wheel so allow a quarter inch overlap.
3. Then from the 8" wheel to the 2" wheel. No light showing.
4. Then the 8" wheel to the tracking wheel. Again allow the quarter inch overlap.
5. Then the drive wheel to the tracking wheel. These are the same width so there should be no overlap.
All of this should make sure that everything is in line and square.
Then if everything checks out check that the belt is tracking on the center of the drive wheel and tracking wheel. If this is not centered use washers to bring them in line.
Belt tension tight enough?
Check that the contact wheels are not worn. They should be flat across the contact area and square to the wheel.
If all that don't do it I would probably take the whole grinder apart, start all over and rebuild it.
If all that don't do it I give up.
 
It's not belt tension, I've got mine so tight they twang like a piano wire.

It happens on every brand and grit belt so i don't think thats my problem.

Wayne, I'm going to go step by step through your process and see if it helps.

The wobble is slight but noticable. I'm never going to get my plunge lines straight with the belt moving back and forth.

Thanks to all for the tips so far. Off to work on the grinder...
 
Thanks Guys

Wayne Coe said:
Assuming your grinder has step pulleys:
1. I lay a straight edge from one pulley to the other and make sure they are in line, no light gap between the straight edge and the pulley anywhere.
2. Next I lay the straight edge on the side of the 8" wheel with no light anywhere and make sure that it lines up with the drive wheel. The drive wheel is about a half inch wider than the 2" contact wheel so allow a quarter inch overlap.
3. Then from the 8" wheel to the 2" wheel. No light showing.
4. Then the 8" wheel to the tracking wheel. Again allow the quarter inch overlap.
5. Then the drive wheel to the tracking wheel. These are the same width so there should be no overlap.
All of this should make sure that everything is in line and square.
Then if everything checks out check that the belt is tracking on the center of the drive wheel and tracking wheel. If this is not centered use washers to bring them in line.
Belt tension tight enough?
Check that the contact wheels are not worn. They should be flat across the contact area and square to the wheel.
If all that don't do it I would probably take the whole grinder apart, start all over and rebuild it.
If all that don't do it I give up.
Click to expand...

Thanks for the info Wayne and thanks for asking the question Chris! I followed the instructions and removed 95% of the wobble. 2thumbs

Here is a virtual beer for all your help.
beer.jpg
 
Wayne covered just about everything you can do. alignment or belt tension is usually the culprit.

After you check all of the mentioned and you still have problems check the drive shaft. Mine was not straight so I ordered the precision shaft from Tracey. That took care of my problem. Also check the bearings in the wheels, make sure they are tight and the wheels don't wobble. Good luck.

Larry
 
Well I just finished working on my grinder. I ended up taking it apart somewhat. I took the pulleys, shaft, drive wheel and pillow blocks off.

Low and behold one of the bearings in the pillow block was not seated properly! I put everything back together and lined it up using Wayne's instructions and my wobble is gone!

I tested 6 different belts on both the 8" wheel and the flat platen and I only got wobble from 1 belt. I'm sure that is the belt's problem.

Thanks for the input.

Did I mention I LOVE THIS PLACE!
 
2thumbsI will move my post to Tutorials, add LR's comments and give hime credit for his contrabution. Chris, I'm glad that we could help.2thumbs
 
WOW!

I just used my grinder on a new blade since I set it up and removed the wobble last night. Maybe it was just luck, but my plunge lines are the best I've ever done! I sure hope this is a sign of things to come. I am so stoked!

Thanks again guys for the help, this just keeps getting better.
 
I have been fighting belt "wander" on my Bader III ever since I got it , and it is progressively getting worse. Does the same on the flat platen , 5" contact wheel and 8" contact.

When grinding the belt always moves to the left , sometimes a good 1/4" to 3/8".

Many calls to Bader , many promises to send something to fix it , no deliveries , and each time I would call back , I had to go thru the whole deal all over again.

After 4+ years , I have learned to live it....but soon I hope to tear it all apart and fix whatever is wrong with this thing , as it is driving me nuts.
 
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