KMG tracking wheel position...

[Troy H]

Today is all about the shop.

I've almost got everything set up. Today I will finish cleaning the sawdust out of the dust collector I got off craigslist, build a spark arrestor for it (already plumbed), and put up a plastic curtain to keep dust from my hobby off my wife's exercise equipment. :thumbup:

The only other thing that needs to be done before I get busy is paint my grinder, but I'm waiting for my MAP Arm to arrive before I do that. While I wait, I find that I have plenty of time to look at the details. And the details can be annoying.

To the heart of the matter. Is it normal for the tracking wheel to need to droop this far to keep the belt in-line? As you can see in the pics, the tracking wheel only contacts one half of the belt. In addition to that position, it tends to give the belt a slight wobble.

Note that I did change the setup slightly from when it was delivered. I moved the locking mechanism to the other side in preparation for the installation of my MAP arm.

Any help or input would be appreciated. Thanks all.

 

[Frank Niro]

Just from the picture it looks like your front wheel is out of alignment in that it sits in an angle down position. This then would require a compensating adjustment as tou have had to make. Is this front wheel loose on its mounting? Frank

 

[P.Brewster]

Something must be out of line. Have you tried a different belt?

It could be the rear wheel.

 

[Troy H]

Hi Frank,

I see what you mean and I ran down to take a look. The 2" contact wheel was inline, but that was definitely the source of the wobble. I put the original wheel back on it and no wobble, but the tracking is still off.

Patrick,

I have tried a few different belts an they all behave the same. Oh, and tracking is the same regardless of if I'm using my contact wheel, platen or small wheel - well, small differences with each. This probably leaves the rear wheel or the tool arm receiver (which was my first guess, I've been trying to adjust this since I first discovered the problem).

I'll take a gander at the back wheel to see if I see something out of whack.

Thanks for the replies so far!

 

[Abrasive]

Yeah that doesn't look right at all.

Can you take a bird's-eye view pic of the whole setup, straight down on the grinder?

Dave

 

[Mark Behnke]

I had the same problem.
When I first set it up last june I don't remember it tracking that way. Noticed it a month or 2 ago and checked drive wheel alignment with contact wheel. Seemed to be OK.
I put a washer at the mounting point of the tracking wheel to space it out and could adjust according to how many washers I installed.

Just went out to take a pic and thought I should use a new belt.
Ended up removing the washers, could use a thin one to put it dead center.

May be just a worn belt I don't know.
First pic is stock mounting second is w/3/32 washer

 

[Troy H]

I couldn't get a decent picture from straight down, but here are a few pics of the setup.

And to give more perspective on where the belt contacts each wheel, here it is once a belt has been run on it.

Mark, it does seem that the tracking wheel is simply too far to one side. How many spacers have you installed? Did it straighten the system out?

Thanks again.

 

[Tait]

Also, moving the locking lever from the left to the right changed my alignment as well. Try putting it back for a bit - I'll bet alignment is back where you'd like it.

I think it's because when the lever is on the left side, it pushes the arm to the right, but when it's on the right side, it pushes the arm to the left. So, there is a difference in alignment equal to the left to right slop between the arm and the slot is slides into.

 

[Mark Behnke]

Mark, it does seem that the tracking wheel is simply too far to one side. How many spacers have you installed? Did it straighten the system out?

Thanks again.

I just posted some pics , 3/32 spacer put it dead center.

 

[Troy H]

Also, moving the locking lever from the left to the right changed my alignment as well. Try putting it back for a bit - I'll bet alignment is back where you'd like it.

I think it's because when the lever is on the left side, it pushes the arm to the right, but when it's on the right side, it pushes the arm to the left. So, there is a difference in alignment equal to the left to right slop between the arm and the slot is slides into.

I thought you might be right, but I switched the lever back to the left side and it's just as bad. I'm very glad about this (?), because I'd hate to have to give up on installing a MAP arm even before it arrived.

 

[Troy H]

I just posted some pics , 3/32 spacer put it dead center.

Thanks for the before/after pics. That seems the perfect fix for a small amount of sag, and that's right where I'd want it, but I wouldn't want to add 5 or more washers to correct mine.

 

[Abrasive]

I couldn't get a decent picture from straight down, but here are a few pics of the setup.

[

I went to take pics of mine, but I don't think that'll help much. So I measured. Just FYi it's a real-deal KMG, about 3 years old. KMG base plate. Tracks perfectly.

Starting at the back...

My drive wheel is 1/4" from the pillow block, or 1-1/4" from the vertical plate that holds the block.

My tracking wheel is 17/64 from the swing block at the top, and 19/64 at the bottom. That's right - the hole was not tapped square. Never noticed that. My tracking wheel has to tip just a bit off "square" in the opposite direction of yours to track just about any belt. Not even close to as much as yours.

On my flat platen, the wheels are both 13/32" from the frame plate. That plate is 1/2" thick Al, so they're 29/32" from the side of the tooling arm. These are the Al wheels, not rubber contact wheels.

Hope this helps a bit. I can measure anything else you like, just let me know.

Dave

 

[Abrasive]

One more, since the focus seems to be on the tracking wheel position:

Measuring from the tracking arm (the piece the big handle screws into) on the wheel side, a rule laid on top of the tracking arm shows 1-15/32" to the tracking wheel. On the bottom of that arm the distance is 1-9/16" to the tracking wheel. Not much tip there. (3/32)

Hope this helps!

Dave

 

[Troy H]

Thanks, Dave.

I just measured my drive wheel again and looking a bit closer, it's off. The drive wheel is 1 3/16" from the plate at the top and 1 1/4" at the bottom. It makes sense that my tracking wheel would have to compensate. I'm not sure it's enough of a difference to have to move the tracking wheel as much as I have, but it's enough that I'll give Rob a call on Monday. Maybe he'll have some ideas.

Thanks again!

 

[Abrasive]

No prob - glad to help pin it down! It's no fun trying to reverse-engineer if it's not working right in the first place.

Rob will take care of you. He's good people.

Dave