Jointer setup and tolerances

[Jake Helmboldt]

I have a few questions on jointer setup that I'm not finding in other threads or at other sites:

1. How crucial is it that the fence is parallel to the tables along the length? It seems like it isn't crucial (as long as it is square to the tables), but I'm not sure. How bad is "unacceptable"?

2. What is acceptable for any "sag" resulting in not being coplanar over the full length of the tables (long 76" tables)?

3. Can the fence be adjusted so there is not so much drag as it slides across the outfeed table? Won't that wear a groove in the table?

Thanks, Jake

[Mark Singer]

The fence does not need to be parallel...there were a few old models where the head ran at a skewed angle to the jointer bed and fence.

the tables must not sag and be in two coplaner planes that are oset by the depth of cut ... any great variation here will resut in snipe or a cut that is not parallel to the face....

the fence should glide above the tables a bit...sometimes there is a nylon button or 2 for support...it should not be metal to metal scoring the tables

[Bill Simmeth]

Ditto Prof Singer's comments. As he describes, the fence on my old jointer can be set skewed to the blades. This is desirable when passing figured wood. The skewed cut helps reduce tear-out to a degree. You don't mention the jointer you have nor do we have a picture of the fence, but many have a secondary pivot point which allows you to raise the fence face slightly off of the table while still being perpendicular to it. Thus, the fence slides only on its base. If it (the base) and the table are well waxed, the fence should slide about relatively easily without harm to the table.

[Jake Helmboldt]

I realize there should be no sag, however, when using a straightedge and feeler gauges, what is an acceptable tolerance over, say 2' from one bed to the other using a 4' straightedge centered on the cutterhead?

As an FYI, I'm setting up a new ShopFox W1741 which is the clone of the Grizzly 490 with the parallelogram beds. The beds themselves are virtually dead flat, but I want to make sure there is no appreciable sag.

The fence on the other hand catches on the table too much so I've got to get that figured out. Other than raising it slightly where it mounts to the jointer is there any way to adjust that?

thanks again, Jake

[Michael Willett]

Jake, Did you get the issues resolved with the setup of your new jointer. I'm considering the same model and would like to hear how its going now.

Mike

[Joe Chritz]

Not sure what is "acceptable" but I have a spot in my out table that had a depresion about .004 just after the blades. If I edge joint a piece there it is tapered every time.

Unless you have a precision straight edge you won't measure much closer that .001 over the bed length anyway.

A starett straight edge of decent quality is about .0002 per foot.

Joe

[Joe Spackle]

I suggest you joint some edges and compare them to determine if your jointer is setup well enough to make accurate joinery.

How many edges? three to be exact. Why because you can easily have two edges that are crowned the entire length and it will appear that you are OK.

the third one however proves the first two. I treat the edges as edge A, edge B edge C. now if you can combine any two of these edges (EA-EB -EA-EC EB-EC) and they all match the entire length of the cuts, you are good to go.

Your machine is new and I doubt that it is that far off to cause consern.

Joe