Jointer Tune Up Question

[Tom Hoffman]

How does one check the "co-planar-ness" of jointer infeed and outfeed tables? I suspect raising the infeed to the elevation of the outfeed, then laying a straightedge across them, but what can I use for a straightedge that spans the entire 66 inches (Powermatic 54)? What would be considered acceptable tolerances?<!-- / message -->

[Steve Roxberg]

Fine Woodworking had an Article on how to make one. Not a straight edge, but three screw heads that are all in the same plane.

I have written instructions I could e-mail you if you would like.

[Tom Hoffman]

Thanks Steve, yes, I would be interested.

[John Hemenway]

Steve, any chance you could post the instructions here?

Thanks...

[Lee DeRaud]

Not a straight edge, but three screw heads that are all in the same plane.Three? I would have thought you'd need two for each half of the table.

[Steve Roxberg]

Ok, I'll try and describe it.

1. You will need three pieces of 1/2 MDF and rip them to 5" in width, and as long as your jointer.

2. Do something to one of the bars, I would cut a hand hold or taper the ends form 5" width down to 3". This will be the Reference bar, the other two will be adjustment bars.

3. On each bar on one edge predrill for three fine thread drywall screws, and insert the screws leaving 1/4 inch of the screw head out. Remove any burrs so that the screw heads are clean and level. One screw on each end, and one slighly off center to miss your cutter head.

4. Your reference board is A, and you have two adjustment boards mark them B and C.

5. Align the screws on A and B and adjusting only the center screw on the B board get all six screw heads to touch.

6. Align the screws on A and C and adjusting only the center screw on the C get all six screw heads to touch.

7. Now place B against C and adjust the center screws on both an equal amount in or out until all six touch.

8. Again place board A against Board B, but this time adjust the center Screw on Board A. Repeat steps 6 to 8, until all screws touch on all boards.

You now have a reference board with three points in a perfectly flat plane that can be used to work on your jointer.

Hope that makes sense?

[Rick Lizek]

A straight edge 2/3 the overall length of the bed is best. It does not have to be the full length. I adjust 8' jointer beds with a 6' straight edge with no problems. The stick with the screws in the FWW article isn't going to pick up dips in the table. The straight edge is the fastest, simplest way to do it. I have machined straight edges because I repair professionally but a decent 4' level or sheet metal shop cut off would work. Lee valley has some reasonably priced ones as well. A feeler gauge will run a few bucks.