Freud shaper cutter problem or technique?

[James Biddle]

I set up and used my new Freud finger joint cutter today and I'm having a problem with the resulting fit. These cuts were made with a brand new Freud UP250 finger joint cutter on my shaper. As you can see, there is a substantial gap that won't close up because the angled side walls are tight and prevent the joint from closing any further. The gap is consistent across the length of the cut and is the same on both sides. I marked both edges with a pencil before the cuts and verified that I removed the complete edge with the cutter. There was no snipe, but I did cut about 3" from both ends before the pics to verify that no end of cut interference took place. My inclination is that I have a bad cutter, but I want other opinions before I travel too far down that road.

[Dale Lesak]

Did you try some glue and clamps to bring it together?

[Joe Chritz]

Is the cut fully engaged? It seems that if the depth of cut isn't enough it would cause that problem.

Joe

[David DeCristoforo]

Offset your infeed and outfeed fences so that you are removing at least 1/32" of material beyond the length of the fingers. Then see how the pieces mate.

[James Biddle]

These were my first attempts using an outboard fence and a finger joint cutter. I made sure the cuts removed about 1/16" from the edge of the second test boards (pics) after the first test ones had the same problem. The boards also travelled tight to the outboard fence for the full length of the cut (no snipe or bumps). I tried to pull them together with clamps, but with no luck.

David, is this the same cutter you use on your chess tables?

[David DeCristoforo]

"...is this the same cutter you use on your chess tables?"

No. If you look at the sample on the web site, you will see that the top and bottom joints on the chessboards are on the same line. That cutter was custom made.

Did you try "going the other way"? In other words taking less material rather than more? You may have to mess with the setup because this is not a reversible cutter. You have to change the cutter height to get the two pieces to mate, right? At least that is the case if this is the cutter I think it is. Try using a shallower depth and "sneak up on it"

[Peter Quinn]

I am thinking the same thing Joe said. I doubt Freud sends out any cutters that just don't work given its all CNC machined. If you have a 6" steel rule you can use that to make sure your out feed fence is flush with the deepest part of the profile, which is essential for this cut to work. I always spin the cutter (by hand with the shaper in neutral) backward until it just drags the ruler but doesn't move it off the fence. You can run the in feed fence back 1/16" to insure a full cut, though I wonder why you are finger joining long grain edges to begin with?

For end grain joints, which is really what this cutter is made for, I'd use a sled with hold downs, back the out feed fence out a bit so it doesn't interfere, and set the in feed fence flush or slightly behind the deepest part of the cutters arc. Then you are just using the in feed fence as a depth stop. This will require a sled with hold downs.

[James Biddle]

"...is this the same cutter you use on your chess tables?"

No. If you look at the sample on the web site, you will see that the top and bottom joints on the chessboards are on the same line. That cutter was custom made.

Did you try "going the other way"? In other words taking less material rather than more? You may have to mess with the setup because this is not a reversible cutter. You have to change the cutter height to get the two pieces to mate, right? At least that is the case if this is the cutter I think it is. Try using a shallower depth and "sneak up on it"

David,
You may have found the answer. I did set the cutter height at the midpoint and flipped the pieces over for assembly. The website info says to raise the cutter by 1/8" for the mating part. I did assume the parts should and would mate perfectly either stacked or reversed. I'll play with it tomorrow and see what happens. I'll also play with the cut depth a little. I may have the wrong cutter for my application.

Peter,
I've gotten several PM's asking me to check the outfeed fence, but neither the infeed fence nor outfeed fence is in contact with the wood at any point in this cutting operation. I'm using an outboard fence, controlling the opposite edge of the wood and using the cutter to dimension the width of the wood in addition to shaping the profile. The primary use of the cutter is for the endgrain of chessboard squares. But, I will also use the outboard fence and cutter on the long grain to ensure perfect squares, not because the long grain requires it for strength. If I were to use a sled, I believe I would lose the ability to create an exact square without extensive setup time.

Thanks for the replies everyone!

[Peter Quinn]

Interesting use of the back fence James. Much more complicated than what I had envisioned you were doing. Do I understand you will glue up 8 wide, rip strips off over sized and run the end grain as a strip?

[James Biddle]

Interesting use of the back fence James. Much more complicated than what I had envisioned you were doing. Do I understand you will glue up 8 wide, rip strips off over sized and run the end grain as a strip?

That's the plan if I can work it all out.

[Chip Lindley]

I'm either 100% right or dead wrong here!

The two halves mate up exactly, making one flat surface, top and bottom. So, your alignment of the cutter to both halves is right on!

The gap you see at the fingers is caused by too shallow a cut in each piece. If your depth of cut were too deep, you would see the fingers mating at bottom and gaps on each side. Increase depth of cut by 1/2 the gap, and pieces should mate up perfectly!

Try it and see if things don't fit as they are supposed to!

[J.R. Rutter]

I may just be too late for my mind to be working, but ...

If you are removing enough material so that the original edge is completely shaped away on both parts, then it looks to me like the cutters are wrong. Are these one piece cutters - no shims? As long as the cut is deep enough, how will making it deeper or shallower affect it?

Likewise, other than getting the faces in the same plane, how is raising/lowering the cutter going to alter the fit?

Why use an end grain joint cutter on long grain? Most long grain glue joint cutters that I have seen are more like shallow 45 degree corrugations than fingers.

[Paul Atkins]

This looks familiar- hmmm. Not totally though. I think it was a glue joint cutter and the center had a gap but the outside was flush and tight. It looks to me like the cutter 'teeth' are the gap width too long. If the tooth didn't cut that wood out, there would not be a gap. Draw it out on paper 4x size and see. This might be a design feature to keep the tips from bottoming out and have the main glue surface loose. My 2c.

[David DeCristoforo]

"I did set the cutter height at the midpoint and flipped the pieces over for assembly."

This might just be the answer. If the cutter is not designed to be reversible, the two halves will/may not mate properly. Since the instructions for this cutter state that the cutter height must be raised by 1/8" to cut the mating piece, it is very likely that the profiles are not designed to mate by reversing the pieces. We will find out once you have tried the cuts according to the instructions. It is odd that this cutter would not be reversible. Isn't there a Freud guy on here somewheres? Maybe he could chime in on this one. I do agree with everyone who questions the cutter depth being the issue. Once you have made a full depth cut, there is not much left to question!

[Charles McCracken]

While it is possible for Freud a cutter to be ground incorrectly, the cases of this are very rare. Depth of cut is the first place to look. Also, since you are cutting with the grain you are possibly getting compression of the grain that could cause this. I am curious as to why you are using a finger joint cutter for long grain joints instead of a glue joint like the UP031. The finger joint is really intended for end grain joints to join short boards into a longer board. I suggest that you try using the cutter for a test in end grain to see if the joint is correct.