snndpaper belts running off

[bensmink]

Does anyone know the cause and fix for my traction belts running off the rollers. The belt to the left of the machine is running off the roller at the far end. The right belt seems to be fine....Thanks, Bob

[DocWheeler]

Bob,

Have you taken that belt off of the machanism? Is this a problem that was this way from the start?
It sounds like the spring on the end that the belt moves toward is somehow not exerting the force it is supposed to.

[bensmink]

Thanks, Doc...No, I have not taken the belt off. The only think I can think of that might be the cause is my head pressure. I have to loosen the four bolts on top op the support rods so they are just slightly over finger tight in order to achieve 75 lbs of pressure. Could it be that they need to be tightned fully to assure that the belts are running true? I will be thankful for your response....Bob

[DocWheeler]

Bob,

If you are having to leave the bolts at the top of the columns loose to get roller pressure, I would think that you need to address that problem first. Chances are that the bottom bolts are holding the posts in the wrong position - might want to talk to LHR about that or remove the bottom and position them yourself.

If all the pressure was being placed on your projects at the keypad edge, I would have expected to see both belts misbehaving. There was a post several months ago where the spring at one end of a roller mechanism was fouled-up and would not function properly - that is what I thought of when I saw your post.

[bensmink]

Thanks, I am going to try to get the paper back to where it is supposed to be(either by measuring a long board so that the long side will "rewind" the belt) or by removing the device and doing it that way. Next I will loosen the bolts all the way then tighten them with the same torque. I will then check my head pressure. The reason for this is that when I got this machine the temp was very cold. I don't believe it had warmed to room temp b4 I checked the pressure. It is a long shot, but, nothing to lose..........Bob
P.S.
I am also going to check out the spring that you mentioned and see if it is haywire.

[David Myers]

If I were you I would pull the belts and look under the belt trays, they have two black guides that help keep the belts on track. If you just let the machine measure a board to run them back on track they could catch on the guides under the belts and tear. The belts are not under the warranty. It is very easy to remove and check.
Just another thought.

David

[ChrisAlb]

Sounds to me like a spring tension issue. I would first measure the width from out to out on the rollers to see if there is any noticeable difference. If not, pull the belt tray out and inspect the springs and measure them as well.

I can't be sure about this and obviously you want it to be right but, I would think the head pressure would have to so severely different from front to back (keypad side to non keypad side) that if that were the cause of the belts running out, the head wouldn't move very easily if at all.

[bensmink]

Well, I took the sandpaper belt and belt tray out of the machine. Nothing was really obvious but a closer look revealed that one spring was sitting against the tapered end of the spring while the other one was on the round side of the spring. I adjusted it so both springs were sitting identical. This did NOT seem to help. The rate of movement is approximately 1/32 to 1/64 of an inch per revolution of the roller. How do I contact LHR. I have to admit that I don't know who they are.....Thanks.Bob

[AskBud]

http://carvewright.com/cms/contact-us

[Digitalwoodshop]

Belts can be a problem....

Causes for the belt tracking off course could be:

A bad belt, worn or stretched on one end. Flipping the belt would tell but replacement is best.

Remove the assembly and blow all the dust out but leave the belt on the assembly.

Make sure the springs are not bound up in sawdust and can move.

Board Alignment can cause a belt to walk, board not against the left guide front and back.

That's my 2 cents.....

AL

Belts are Cheap... Replace both while you have it apart. Cheaper then spoiled WOOD later...