Jointer fence flatness

[BuckeyeDennis]

Hi All:

I bought my Shopsmith jointer (Type C) on eBay a year or so back. I replaced the bent tilt quadrant and performed the blade sharpening and alignment procedures. The infeed and outfeed table alignment seem good, and I can consistently joint edges straight to within maybe 0.001" per foot.

But this last weekend, I encountered a problem when jointing some cherry boards to glue up into panels. The edges were nice and straight, but I couldn't consistently get them perfectly square. This resulted in the unglued panels having a slight cup when the boards were stacked together on edge.

The root problem appears to be that the face of my jointer fence is not terribly flat. Checking for square at alternate ends of the infeed table, I can detect a slight twist in the fence. In addition, I was able to see a slight concave bow (lengthwise) in the fence, which a good 24" straightedge confirmed. So I believe that the non-flat fence surface is thwarting my best efforts to keep the board at a consistent angle while jointing.

Does anyone have any suggestions for how I might be able rectify the problem? I do also have a 4E jointer that came with my 10 ER -- if the fences are interchangeable I could clean up the surface rust and use that one. Or is this the sort of thing that Shopsmith warrants for life? Failing either of those, a surface grinder could certainly make it flat, but I'm not sure how it might be fixtured for grinding.

Then again, maybe being a fuzz off square is something that can be dealt with during glue-up? Any advice would be greatly appreciated!

[dusty]

Hi All:

I bought my Shopsmith jointer (Type C) on eBay a year or so back. I replaced the bent tilt quadrant and performed the blade sharpening and alignment procedures. The infeed and outfeed table alignment seem good, and I can consistently joint edges straight to within maybe 0.001" per foot.

But this last weekend, I encountered a problem when jointing some cherry boards to glue up into panels. The edges were nice and straight, but I couldn't consistently get them perfectly square. This resulted in the unglued panels having a slight cup when the boards were stacked together on edge.

The root problem appears to be that the face of my jointer fence is not terribly flat. Checking for square at alternate ends of the infeed table, I can detect a slight twist in the fence. In addition, I was able to see a slight concave bow (lengthwise) in the fence, which a good 24" straightedge confirmed. So I believe that the non-flat fence surface is thwarting my best efforts to keep the board at a consistent angle while jointing.

Does anyone have any suggestions for how I might be able rectify the problem? I do also have a 4E jointer that came with my 10 ER -- if the fences are interchangeable I could clean up the surface rust and use that one. Or is this the sort of thing that Shopsmith warrants for life? Failing either of those, a surface grinder could certainly make it flat, but I'm not sure how it might be fixtured for grinding.

Then again, maybe being a fuzz off square is something that can be dealt with during glue-up? Any advice would be greatly appreciated!

I believe you are saying that the fence is not square to the table at all points across its entire length.

If that is correct, is the fence square to the table at the in feed end?

Hmmm A .001"/foot. I am not certain that I would even notice that. In fact, I am not sure I can even see that if looking for it.

[BuckeyeDennis]

I believe you are saying that the fence is not square to the table at all points across its entire length.

If that is correct, is the fence square to the table at the in feed end?

Hmmm A .001"/foot. I am not certain that I would even notice that. In fact, I am not sure I can even see that if looking for it.

Correct .. if I set the fence so that it is square to the infeed table back by the quadrant, it is not square at the infeed table up near the cutter head. So if the infeed table is flat, then the fence must have a twist.

In addition, the fence has a slight bow to it, lengthwise.

I'm quite happy with the .001"/foot straightness of jointed edges. That number is just a guesstimate from observing the gap between two jointed boards held together. Slight clamping pressure closes up the gap completely.

[dusty]

There is no comfort in this at all but if I put a straight edge against my jointer fence I have a gap that begins about at the counter head and extends toward the out feed end for about 3" or 4".

I never noticed this before.

[nuhobby]

I wonder if you can do the old hand-tools trick of ganging your to-be-glued edges together in pairs as they pass through the jointer. Then edges that aren't perfectly 90 degrees to the faces will cancel out, come glue-up time.

[BuckeyeDennis]

I wonder if you can do the old hand-tools trick of ganging your to-be-glued edges together in pairs as they pass through the jointer. Then edges that aren't perfectly 90 degrees to the faces will cancel out, come glue-up time.

That sounds like a great idea! I think it would compensate even if the angle varied a bit over the length of the boards.

At first, I was wondering how I could clamp a pair of boards securely together for jointing, without interfering with the fence -- I could see it being a problem keeping the bottom sides of the boards squeezed together. Then I remembered that I scored a good assortment of pinch dogs as part of the 10ER deal. Those work great for pulling the ends of boards together, and only make a mark in the end grain. But first, I'd have to convince myself that there was no chance of one falling out and landing in the cutter head.

[reible]

Hi,

I don't own a shopsmith jointer so I have no advice I can give on that subject.

I have for the last some years started using glue line rip blades, They are towards the top end blades and I have been very happy with the results they provide. (infinitytools.com)

In most cases the cuts are good to go right after the sawing operation and I don't need to use the jointer. If I had to give a number I would say my jointer use is down 90%.

I can't promise you will have the same results but it might be something to think about.

Ed

[ChrisNeilan]

Double stick tape should do the trick...

[STB]

Hi All:


The root problem appears to be that the face of my jointer fence is not terribly flat. Checking for square at alternate ends of the infeed table, I can detect a slight twist in the fence. In addition, I was able to see a slight concave bow (lengthwise) in the fence, which a good 24" straightedge confirmed. So I believe that the non-flat fence surface is thwarting my best efforts to keep the board at a consistent angle while jointing.


Then again, maybe being a fuzz off square is something that can be dealt with during glue-up? Any advice would be greatly appreciated!

I bought my SS with jointer in 2011. It was delivered new to the original purchaser in 2003 so I assume it has the newest casting available.

While attempting the first project that required glue up I had unacceptable gaps after jointing . At that point I assumed the front and back beads were not Parallel. To spare all the details I found the beds were parallel within half of a hairs width on a Nat's back end so that meant the fence was twisted or machined incorrectly over its length. Takeing the fence to a machine shop was cost prohibitive.
My work around is, after jointing the edges I run the pieces Through the conical sander. I run the first board face up and the second board face down. This compensates for any variance from 90 deg. in the setup.

The three pictures are of my current glue up project. I am attempting to show the final result after edge sanding with the conical sander.

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[nuhobby]

Double stick tape should do the trick...

Very good idea! I've started to use that stuff a lot on my OPR station, to hold small pieces onto larger sleds.