Wide Belt Tracking problem..

[Rick Fisher]

Hoping someone else has had this problem.. This is the second time for me ..

New belts that won't track on a Wide Belt Sander.

The Sander is an SCM Sandya Win..

The first belts that did this where from Grizzly.. Cheaper belts, made in China.. I decided it was my own fault for getting lower priced belts..

Today, I took a Fuji belt off because its done.. and installed a SIA Cloth belt.. Same problem .. Machine starts up, the tracking cant keep the belt on the spindle and the sander shuts down on its own..

This sander is Pneumatically tracked.. sensors tilt the head when the belt have gone too far.. The sensors are the pink stick kind, not laser, so there is nothing to clean..

My gut feeling is that the belts have been stored too long.. About 3-4 months.. They have a " shape " to them which resembles them being stored.. but the sander tensions them and the shape disappears.. wondering if I should heat them up in the house ?

Anyway.. I need them to work.. I have 3 glue ups to sand for tomorrow.. Very irritating, I don't have another belt available .. Sigh..

[J.R. Rutter]

On the motor side of the machine, the air cylinder that actuates the oscillation has an eccentric mount. You should be able to loosen a set screw and turn the mount to alter how far the cylinder pushes to move the belt back and forth. I happened to have a pic of this that I took for someone else having a similar problem. The bolt at the top is the lock for a set screw running down through it to lock the eccentric in place. The allen screw thing on the right is the adjustment for the eccentric. Hope this makes sense and that your sander is like my 5RCS ...

https://lh5.googleusercontent.com/-0nc-5dchUd8/TLiCbr4i6aI/AAAAAAAAAtQ/YbRT_5h34XU/s576/IMG_0710.JPG

edit: I pulled the WIN manual off of parts pronto and at least the newer (2000+) models have the adjustment that I mentioned in the OPS manual. You can also try turning the belt around to run "backwards" though if it was glued up with one edge slightly longer than the other, then it will want to track to one side. The oscillation adjustment has worked for me when I've run into this situation.

[james hepp]

There's a spring that is part of the tracking control system which sometimes breaks, (lack of correct tension on it's components, of course)

THis happened on my widebelt some time ago, and when this was finally discovered, I soon learned that a replacement was 6-8 weeks out.

solution,
a like sized valve spring from an Audi 4cyl. 20v (I think it was an intake valve spring) and my sander was back in action . -it still runs to this day on that automotive spring.

I don't have any diagrams to point this out, and it is extremely hard to explain due to the complexity...
have you seen the tracking component which uses the spring I am talking about?

[Rick Fisher]

Thanks for the help..

Weirdest thing.. I tried 2 x SIA belts.. both tracked off the left side.. Flipped both belts over so they where running backwards.. both tracked off the same left side of the machine.. I would have thought they would have tracked off the other side of the machine ???

So I grabbed the old Fuji belt and re-installed it .. It tracks fine.. no problem at all..

The Cloth belts are thicker.. I will have to try the adjustment JR .. thanks very much.. This Wynn is an early 2000's model, white body.. so the adjustment should be the correct.. I am willing to bet the thickness of the belt is the problem.. Needs more oscilation as suggested..

So annoying to have a project due, a box of belts, and nada.. Zip.. I could probably sneak by with the old belt but it should have already been switched a few miles earlier..

Stuff like this causes my blood pressure to rise..

[Rick Fisher]

http://i335.photobucket.com/albums/m455/jokerbird_photo/P1010664.jpg

Hey JR.. This looks a bit different than yours ?

Not sure how it would be adjusted ? I could see pushing it further one way or another, but not sure how to increase the stroke or decrease it ?

How are the Pneumatics Lubricated ?

[J.R. Rutter]

A bit different, but the post sticking out from where the cylinder is mounted to the frame of the machine is where mine adjusts. The stroke length is the same, but changing the starting point for the stroke via the pivot position alters the way the belt tracks. I just run the machine while I turn the pivot to find the best spot for even back and forth motion of the belt as it runs.

My sander has central filter (not sure about lube) and a couple of pressure regulators inside the main electronics panel.

As an aside, even though sanders are designed to run with some dust buildup, it looks like you could use some more dust collection capacity. :-)

[Rick Fisher]

Yeah.. I gotta do some interior cleanup on this machine.. lol The issue is leaving too many gates open.. sloppy.. I gotta start closing gates on other machines when I am finished..

The piston does not move very much.. its not a big stroke.. I find it kinda confusing..


JR .. If you read this .. what is the pressure set to on your system ? I am at just over 3 Bar.. Which seems like maybe its too low ? I don't have an owners manual for this machine, so left it where it was when I bought it .. ( I got it used )

http://i335.photobucket.com/albums/m455/jokerbird_photo/P1010668.jpg

I wonder if with a thin paper belt, it would still track with low pressure.. if the belt was thicker, it may not ? I will see if I can find a manual online.

[Walter Plummer]

I know it sounds crazy but we have cut plus or minus 1/2" off the edge of some belts and then they would run fine.

[Rick Fisher]

I think the issue is actually that the oscillation system is not centered properly.. on a thin belt, it was good enough, on a thicker cloth belt, its not enough.. The belts run off the same side of the machine irregardless of if they are run backwards or properly, so its got to be the machine ?

I got an owners manual online which says how to adjust the Oscillation system.. Not really sure which direction to adjust it but I suppose it will run off the machine faster or slower than it did ..

[J.R. Rutter]

6 bar and 2.5 bar are what my manual says to set these regulators.

One other note. The return spring in one of my pistons got weaker and weaker over time. I didn't bother to rebuild it yet, but did add a spring on the outside to help pull the oscillation back. If you can use you hand to push the piston back while it is running and this makes the belt track better, than this might be a solution.

[Jeff Duncan]

I would check recommended pressure for your machine. On my Timesaver it recommends 40psi for paper, and higher, maybe 60?,psi for cloth. I can find out exactly tomorrow but your machine may differ anyway.

As far as shape or storage go I don't think that would be a problem. I have belts that are easily several years old that track fine.

Good luck,
jeffD