Replacing Sliding Saw Subrollers

Tips on an often-overlooked maintenance task. June 5, 2006

Question
We are about give our Altendorf F45 a tune-up. We've done this several times and have got most of it figured out. As part of a preventive maintenance program we decided to change out the six nylon sub-rollers. The two at front and back are obvious. I can remember the Altendorf salesman describing the process for accessing the middle two rollers but I can't remember what he said.

As I recall, it had something to do with the black plastic gizmo that is exposed on the top part of the beam when the stroke is at either extreme. I think it had something to do with disassembling the beam for shipment. If anybody is familiar with how to change these center rollers, I would sure appreciate to know.

Forum Responses
(Cabinetmaking Forum)
From contributor M:
Mine is an '02 and there is a trolley and when you push the carriage all the way forward it is somewhat exposed, and has a grey rod with a black knob. You pull the black knob towards you and continue to push the carriage forward. You should have easy access to the rollers. Are yours that worn, or is it just out of adjustment?


From the original questioner:
We bought our Altendorf new in 1991 and everything seemed to be rolling fine. We added a Tiger Stop to the slide side and figured that with the extra weight of the aluminum and control box it might be a good idea to check the rollers. As it turns out, a couple of them weren't spinning as freely as the others. Since the machine was down for the tune-up I figured it couldn't hurt.

From contributor P:
I'm not certain of this, but there's something in my manual about the subrollers being set with different play depending on whether they're mid-table or end. Mine are a little sloppier on the ends than the mids, and I seem to remember the manual saying that's Altendorf's factory setting. There was no info on replacing or resetting ("qualified" technician required), so any information would be appreciated,


From contributor M:
Setting the rollers seems to be more art than science. They should be set just tight enough that you cannot stop them from rolling as you move the carriage. You should have a special wrench to do this. I have had Stiles out to look at my carriage, and eventually I had it inspected.

From contributor I:
The subroller track on most of the current Altendorf saws is slightly arched. This will make the subrollers tighter as they get closer to the cut line and looser toward either end of the slider travel. Most Altendorf saws have 10 subrollers. If you divide the slider down the middle, 6 subrollers will be on the left, while 4 will be on the right.

The way I typically adjust them is so the subrollers are loose enough to turn with your fingers (as you move the slider) until they are approx 8-12" from the main table (not the extension tables). I check the 4 subrollers on the right side of the slider against the right side of the main table and the 6 left subrollers on the left side of the slider against the left side of the main table. At that point they should be tight enough so that they cannot be turned with your fingers (or cannot be prevented from turning with your fingers while moving the slider).

Older saws that use phenolic slides will be more difficult to dial in since the phenolic tends to wear. It will be almost impossible to put your fingers on the subrollers on older saws as well due to the shape of the slider extrusion. In this case, use a marker or some sort and mark lines around each subroller, and then watch them from the end of the slider to see when they begin to turn.


From the original questioner:
We bought our altendorf new in 1993. It has phenolic ways on the beam. We just changed all the sub-rollers, at a cost of about $28 a piece. This was just something we decided to do as an adjunct to adding a Tiger Stop to the crosscut fence. There wasn't anything else driving this decision.

As it turns out, the original wheels were in pretty bad shape. Some of the bearings did not turn smoothly and some the nylon wheels were cone shaped. You couldn't tell this from running the machine. Our cuts were all square and the slider seemed to run pretty smooth, without resistance.
I should comment that we are not a high-production shop. This would suggest that maybe these wheels should be part of a preventative maintenance program every couple of years.


From contributor I:
Good call on replacing the subrollers. I wish I had more customers like you who realize that these things wear out. I'm not intimately familiar with the Tiger Stop; however I have seen some of their new designs that are very similar to the ball screw mechanism that Altendorf uses. Most notable is the improvement of the rip fence on the WA-8.

For what its worth, Altendorf has upgraded the subrollers with a new type of bearing which you may have received when you replaced yours. Rather than the older style using a metal shield on the sides (covering the ball bearings) they have moved to a plastic sealed type. This should keep a lot of the dirt and sawdust out of there and your slider moving smoothly.