Troubleshooting Split-Fence Accuracy

A split fence on the shaper allows for quick setup, but it takes time to learn how to set the fences accurately. August 29, 2006

Iím changing my procedure for door making. My current setup is a single end tenoner and one shaper. The setup for the sticking was to use outboard fences and a power feeder. This setup was very accurate but time consuming to change the fences. Iím now trying the split fence that came with the Powermatic shaper. This setup is much faster than my old method. Iíve noticed a few problems. Some of the pieces were cutting on a taper, but not all. A few looked to be cutting the long edge concave. It was taking more off in the middle of the piece and less near each end. Iím wondering what methods others use for their setups. I did setup the far fence with a dial indicator to make certain the fence surface and the cutter was on the same plane. I think some of the problem is the speed. I have the power feeder set. Itís now on the second lowest speed and this is needed to eliminate burning on the edge of the Cherry parts. The speed is still faster than I would like and itís difficult to be certain the piece stays against the fence. I also tried adding a feather board under the power feed to add side pressure but Iím not certain this has been an asset.

Forum Responses
(Cabinetmaking Forum)
From contributor A:
I don't use the fence that comes with the machine. I use the miter slot as a guide and fit a board in the slot and position the power feeder pushing against it. I use different width boards which will give me different width cuts. The pieces never move toward the cutter head when run which ruins them. I can change back and forth to different widths in seconds. Also, make the boards 5/8 thick so the power feeder will only grab the board running, not the fence.

From contributor B:
You should not need a dial indicator for anything but setting the knives. 99% of setup on a shaper is trial and error. Set the machine up by eye and a ruler, and then run test cuts to get the correct cut. I usually eyeball the depth of cut (1/32Ē - 1/16"). Take a 3' long piece of wood and freehand about the first 6" of it. Shut the machine off. Now use your test cut to set the 2nd fence. After a couple of years you will be able to get a perfect cut on the 2nd or 3rd adjustment. A couple of things to keep in mind - use disposable fences and push them into the cutterhead. This will keep the machine from sniping. Also, you don't need more than a couple of degrees of angle on the power feed. Really pushing hard on the part can cause a few problems. I run my 3/4" wide cabinet door muttins with a powerfeed on fences. This works on parts longer than 5".

From contributor C:
When running split fences, both fences must be perfectly parallel. I have always had to remove the assembly with both fences locked in place, then remove the fence stock, (wood or a laminate back splash or MDF), then take the entire assembly to a machine shop that has a belt grinder, (used to resurface engine heads) and have them flatten and parallel up the iron that the fence material bolts too. Then you can set the infeed fence to burn an 1/8th or so, then it hits the outbound fence, which is now parallel so you can hold tight to the outbound fence and get zero snipe.