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.
http://home.comcast.net/~jbiddle/pics/cutter1.jpg
http://home.comcast.net/~jbiddle/pics/cutter2.jpg
http://home.comcast.net/~jbiddle/pics/cutter3.jpg

[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.

[Brad Shipton]

Is that 3/4" thick stock? I am pretty sure that cutter by itself is limited to 5/8" thick stock. If it is 3/4" thick I am curious to hear if it works in the end as i looked into one previously, but held off since i would need multiples for my common projects and there are better options for a few dollars more with insert knives and adjustments for the tightness of fit.

Brad

[James Biddle]

OK, here's what I tried today.

1. I ran some new stock through by taking a full cut from both pieces, and turned the piece over to fit them. Same result.

2. I backed off the fence until the cutter barely took a full cut, and turned one piece over to fit them. Same result.

3. I backed off the cut even further until the outer edge of the board was not removed by the cutter, and turned one piece over to fit them. Same result.

4. I reset the fence to take a full cut from both pieces, and lowered the cutter such that there were no flat surface remaining on the bottom of the cut. I cut both pieces and then raised the cutter up to continue the cut to the top of the pieces (think stacked cutters). I turned one piece over to fit them. Same result.

5. I continued to take a full cut on the first part in the same manner as in step 1. I then raised the cutter by the recommended 1/8" and cut the second piece. I them raised (or lowered) the cutter to continue the cut as if I had a stacked cutter. I fit them in the same orientation as the cut. Same result.

6. I continued to take a full cut on the first part in the same manner as in step 1. I then raised the cutter by the recommended 1/8" and cut the second piece. I fit them in the same orientation as the cut, but they would not fit since the top of the first and bottom of the second piece had a flat that would not fit into the angle of the other.

Two things I have yet to try are:
A. Plane the parts down from 3/4" to the 5/8" maximum recommended thickness for a single cutter. This shouldn't be an issue since they advertise being able to stack the cutters.

B. Make the cuts on endgrain instead of the long grain in case Charles' idea of fiber compression is right. But, it doesn't say endgrain only from any documentation I can find.

I'll try those in a day or so. Regardless of the results, I think I may have the wrong cutter for my application.

[Peter Quinn]

Hmm, been running this through my mind till my eyes started to twitch, going back and forth from your pics to the Freud diagram. I have only two slim notions. Are you quite certain that your spindle is perfectly perpendicular to the table? Out of perpendicular even a few thousands can cause strange problems with some machined joints that might not show up in other operations. Its a long shot but worth checking. Best way I know is to chuck a straight edge between two spacers on the bottom of the spindle, held on by the nut, and slowly lower it until it touches the table, then raise it a measurable amount with a feeler gauge and check all points around the circumference it makes as you spin it by hand slowly.

My other thought was to perhaps pass each piece twice with the same set up given you are using a back fence to perhaps overcome any compression that may be occurring. Short of that I can see no reason for the gap in your pictures other than a problem with the cutter. It seems to me they should align in terms of depth regardless of the height of the cutter assuming you are taking a full depth pass on both adjoining edges as you have verified.

I'll be curious to know what the solution turns out to be.

[James Biddle]

Peter, although I have not check how perpendicular my spindle is to my table, I can tell you that I've had no issues on any of the recent doors/frames that I've run and that the gaps in this problem are consistent left to right and top to bottom, which makes me think everything is still aligned (this is a pretty beefy spindle assembly). Good idea to verify it though.

Charles (Freud), my assumption all along has been that I must be doing something wrong because the odds of your manufacturing tolerances involved in grinding a cutter would normally be far superior to the tolerances I can achieve in using those cutters. Although this is my first Freud shaper cutter, I have many Freud products and every one of them has performed flawlessly to date. I do, however, need to identify source of the problem and make the corrections so I can continue with my work.

To that end, can you tell me why some cutters are labelled as reversible and some are not labelled either way? Does it mean that if a cutter is not labelled as reversible, that the the adjoining parts MUST be held in the same orientation as they ran through the shaper? Or, does that mean that it might work either way and that parts run on cutters labelled as "reversible" MUST be reversed?

Can you also point me to specifications of this cutter so I can measure the affected areas? Most of your sources point me to overall dimensions and not the detailed dimensions.

Your other question was as to why I would use a finger joint cutter for long grain parts? I had three goals in mind while selecting this particular cutter for use building chessboards. First, I wanted a cutter that would remove the entire edge of the part so I could use that cutter to give me a final dimension by using an outboard fence and trapping the part between the fence on the cutter. Second, I wanted a cutter that would give me the maximum glue surface on endgrain that was possible. Third, I wanted a cutter that would work equally as well on end grain as long grain so I could manufacture parts to exact width. Since both a finger joint and glue joint cutter should work equally well on both end grain and long grain and finger joints have more glue surface than glue joints, and no documentation that I found contradicted these requirements, I selected the finger joiner cutter. My assumption all along was that a finger joint referred to the profile of a cut, not just the typical endgrain orientation used in joining long boards (i.e. molding). I could have just as easily ordered a glue joint cutter.

Next, I performed tests yesterday (see above post) that varied the depth of the cut as well as the height of the cutter, but only on long grain wood (I was thinking that if I can't make that cut correctly, the end grain would be useless for my project and, therefore, moot). I still want to perform that test to help diagnose the problem, but my intuition tells me that this will not help produce the results I'm after.

Lastly, please do not interpret this post in any way that would lead you to believe that I do not have the utmost repect for you or your product. I am and remain a loyal user and will have no problem in posting my error if and when we diagnose it.

James

[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.



David, what was lacking in the avaiable cutters on the market that led you to have one custom made? The top/bottom alignment that a normal glue joint cutter didn't provide? More glue surface? Cutting range?

[David DeCristoforo]

I have been messing around with the images of that cutter and I'm pleased to tell you that I haven't got a clue why your pieces will not mate. Cutter height cannot have anything to do with it. That should only affect the alignment of the faces. And if you are taking a full cut, the depth must be correct "by default". I am surprised that Charles cannot answer this. No offense to him but his suggestion (compressed wood fibers due to cutting "long grain") is flimsy at best.

As to why I had my cutter made, yes, I wanted to top and bottom to align so that the board squares looked the same from either side. And I also wanted two full "fingers" with around 1/32 - 1/16" of vertical face at the top and bottom of the cuts to minimize the effects of expansion and contraction. What I am trying to accomplish with this is to eliminate or minimize what I call "ridging" which is being able to feel the joint lines between the squares as the board ages. When they are new, they are perfectly smooth and flat. Over time, ridges can appear between the dissimilar woods that form the dark and light squares. By keeping the vertical joint lines at the faces to a minimum, this is much less likely to occur. I'm giving away secrets here now.... But what the heck... the "high end" chess market is not exactly hopping these days!

[James Biddle]

I have been messing around with the images of that cutter and I'm pleased to tell you that I haven't got a clue why your pieces will not mate. Cutter height cannot have anything to do with it. That should only affect the alignment of the faces. And if you are taking a full cut, the depth must be correct "by default". I am surprised that Charles cannot answer this. No offense to him but his suggestion (compressed wood fibers due to cutting "long grain") is flimsy at best.

As to why I had my cutter made, yes, I wanted to top and bottom to align so that the board squares looked the same from either side. And I also wanted two full "fingers" with around 1/32 - 1/16" of vertical face at the top and bottom of the cuts to minimize the effects of expansion and contraction. What I am trying to accomplish with this is to eliminate or minimize what I call "ridging" which is being able to feel the joint lines between the squares as the board ages. When they are new, they are perfectly smooth and flat. Over time, ridges can appear between the dissimilar woods that form the dark and light squares. By keeping the vertical joint lines at the faces to a minimum, this is much less likely to occur. I'm giving away secrets here now.... But what the heck... the "high end" chess market is not exactly hopping these days!

I've got a total of 2 chess boards and 1 chess table to build (for friends), so I'm not exactly planning on hopping into the chess board market. I would like to build them to the best of my ability though.

I'm curious about your cutter though. If the top and bottom are aligned, you essentially have my basic Freud cutter design, but with custom dimensions, right? How do you match up your two parts?

[Joe Chritz]

If the top portion of the cutter you had was gone it would be (or appear) to be what David uses on the boards.

If you zoom in on the pic you can see that the top and bottom edge are both "on the flat" that allows the board to look the same from the top and bottom.

If your only going to worry about one side (which is all I ever do) then it really makes no difference that I can see.

I may be way off since the only chessboards I have done have been veneered. Unless you count an end grain cutting board, I guess if it had 64 squares you could play chess on it. :cool:

Joe

[Peter Quinn]

Peter, although I have not check how perpendicular my spindle is to my table, I can tell you that I've had no issues on any of the recent doors/frames that I've run and that the gaps in this problem are consistent left to right and top to bottom, which makes me think everything is still aligned (this is a pretty beefy spindle assembly). Good idea to verify it though.

I admit its a long shot on the spindle issue but I'm thinking a minor error in spindle alignment may create problems on a repeating precise profile like this that will not present itself on a simple cope and stick operation. I recently built a jig to make large box joints on a TS, 1 1/4" fingers with a 3/4" dado set on large panels joined to make a chair. Different thing but similar geometry.

I found, as my fingers were very measurable with calipers, that any minor misalignment would make the gap smaller and the fingers larger, or vice versa, creating either a non fit or a loose fit. Given the angles on the finger joints I'm thinking that a fractional change in this angle from spindle misalignment could both subtract and add error similarly. Easy to verify in any event. I think I received that spindle check procedure in some Freeborne literature?

Another thought I had was that perhaps you could overcome the problem by running two passes each with the spindle height raised for the second pass several thousands to spread the fingers and allow them to close over their depth and leave room for glue. Perhaps even just on one side of each joint?If you have a dial indicator with a magnetic base it is a simple affair to test.

[James Biddle]

OK, some updates on the tests I've done. Making the cuts long grain or cross grain have no effect on the fit. Also, every test I've done to check the squareness of the spindle to the table has shown them to be square to the limits of my testing ability. I also tried double passes to no avail.

I agree with David and others that cutter height should have no effect on the fit. I've also tested various depths from not taking a full profile to taking a full profile and none of any of these changes makes any difference.

Charles, I'm at a loss as to what to do other than to return the cutter. I'll still support Freud products, but this one isn't working for me.

David, other than dimensions (OK, and fit), how is your setup for these cuts different than mine?

[Chip Lindley]

I just deleted everything I wrote. The more I Puzzle, the Looker I get!......

[David DeCristoforo]

"...how is your setup for these cuts different than mine?"

I run my stock between the cutter and the fence using a power feeder. My cutter is a reversible cutter. Center line of the cutter = centerline of the stock. The first pass (face up) takes off a full edge and "sizes" the strip. The strip is then flipped (face down) and run again to shape the other edge. Don't know if that's different from what you are doing but my cutter does not require a height change like the freud knife does. Your situation is still baffling to me. I'm almost tempted to buy one of those cutters and try it out. But only almost....