Low-tech panel squaring

Methods and machines for squaring that don't involve CNC equipment. April 9, 2003

I'm searching for an efficient, low-tech (non-CNC) method for squaring panels. Efficient is the key word here. My experience with sliding-table saws has been less than encouraging. (Have used Griggio and Laguna.) Small shop verticals are okay for rough cuts but not good enough. I was spoiled by a big Streibig a few years back. Maybe some kind of manual router based machine or jig that I'm not familiar with would be okay. Right now I am using a hand held circular saw with a straightedge and square and fine tuning with a router with a pattern bit and a straightedge. It works, but it's slow and temperamental. Panels narrower than 16" I do on the tablesaw with a shop made cut-off jig and am happy with that, but wider stock is the problem.

Forum Responses
(From WOODWEB's Cabinetmaking Forum)
Use a *good* sliding table saw (Altendorf), and set it up correctly.

From contributor R:
Being a cheap Luddite restricts me to an ancient Powermatic with an Excalibur slide attachment, but by tuning with a Master Plate and Gauge, I will put the squareness of my panels up against the Streibig's as long as it isn't a race.

I agree with the first response. A good slider is what you need. Both the Griggio and Laguna are capable of cutting square panels. A little maintenance and fine tuning go a long way.

From contributor K:
"I'm searching for an efficient, low-tech (non-CNC) method for squaring panels."

Make a sled from 1/4" thick plywood that has a good core and is as flat as you can find - about 30" x 48" for a Powermatic 66. You will need a side extension on your outfeed table to support most of the sled. Leave about 12" or so of space between the saw table and this side extension so you can clamp stops to the sled when you want. Use hard maple or white oak for the guide runner in the saw-table slot. Mill the width dimension so the strip slides with barely detectable deflection. Surface both sides of the plate with vertical grade plastic laminate. One piece on top and two pieces on the bottom. The two bottom pieces of laminate are butted to the guide strip and form a shallow groove to position replacement guide strips when they wear out in a few years.

Use #8 FH screws to attach the guide strip and the backstop (hardwood, 48" long x 5/8" thick x ~1 1/2" wide) to the rear edge of the laminated sled plate. Use plenty of screws - spaced about 3" apart is good. The backstop positioning is where the magic happens. When it's tweaked to an exact 90 degrees, panels up to 27" wide can be squared with ease. The whole deal weighs only a few pounds, so you can flip it on and off the saw one-handed and lean up against something handy so it's fast to use. I set up a slick-surfaced outrigger and use the sled to square up refrigerator panels and particleboard substrate for countertops. Cotter-pin simple, cheap, fast to use, accurate, long-lasting - what more could one want?

I have done what contributor K suggests and I achieve pretty decent results. The only pain is trying to keep the hardwood fence perfectly square while putting in the screws to secure it. Moving the jig on and off takes a little time, and it takes a little shop space leaning up against my lathe, but it's a lot cheaper than a $10k+ slider. I can get up to 24" width on mine... anything over (less than 5% of the time for me), I'll pull out the circular saw. Only other suggestion is as a safety measure, put a big hardwood block behind the fence to bury the blade into when finishing the cut. I currently am using this on a Powermatic 66 and have been considering getting another without a fence just to leave this jig on it all the time.

From the original questioner:
Just for the record, I do use sleds, big and small, for many operations on the tablesaw. Wide panels is not one of them. I've started the search for a sliding table attachment, although I hate the thought of sacrificing all that space. Other than the Excalibur, which looks good in the catalogues, does anyone have a favorite aftermarket unit to recommend?

I do have an Excalibur and I get good results from it, but since I bought my Safety Speed Cut XL 7400, it gets very little use. The panel saw is much more accurate and one person can cut full sheets very easily. Yes, it is more money, but worth every penny. Accurate Technologies is coming out with a digital readout for this saw, which I am going to look into very soon.

We've been using our Excalibur almost daily for 2 1/2 years and are very happy with it. It's not the Altendorf I used to have, but then the total cost was equal to 1 month's payment on the Altendorf.

I personally don't think the Excalibur sliding fences look good in the catalog (they didn't look too sturdy to me), but they sure work good in the shop. They are, however, only as good as you set and tune them up. I set up mine and took a day to tune it properly and haven't had to adjust the table in the 5 years I've owned it.

There may be other aftermarket sliding fences out there, but this one has a well-established reputation for customer satisfaction, which is not to say that everyone who has ever used one is satisfied, but that the Excalibur is working well for many shops, including mine, and has received more positive reviews than any other I'm aware of.

What I particularly like about the Excalibur is (first) the table and rails run on roller bearings that are easily adjusted to take out slop, and the table's ability to stay in tune. Second, the fence is very high quality machined aluminum, quick and easy to remove and replace when required, without losing its crosscut accuracy. Finally, the fence is very easy to micro adjust (square to the blade) with a locked threaded bolt, any time you want to tweak it for dead crosscut accuracy.

Other features I like are the high quality, simple to move, adjustable stops. I have two on my fence and find the second one very handy for the times I need to interrupt my first cut length setting, during a run of parts - I simply flip up the first stop (out of the way) and use the second stop for the odd length cut. After making that cut, I can return to the first stop and know that the length will be dead on with the remainder of the parts, since I didn't have to move the first stop.

The standard sliding stop on the fence will allow up to about 65" to the left of the saw blade (depends on how far you place the right end of the fence away from your saw blade). There is a built-in, sliding fence extension on the left end of the fence that slides out and can be locked in placed for longer lengths, up to full 8' length of standard sheet material.

You can locate the fence behind the panel, (as I do for 99.9% of my work) which will allow stock up to 36" to be crosscut, or you can locate the fence ahead of the panel for full 48" crosscuts - which I rarely do - but it's possible with the Excalibur with a minimum of fuss. Miter cuts are very easy to set up with the fence and graduated miter rail along the left side of the table, and returning to square is very fast and accurate because of the stop screw built into the system.

Only drawback: It takes up a lot of floor space, but I don't see how to make it less. If you have the room, I believe you will be satisfied with the Excalibur sliding fence, at least until you get that Altendorf :-)

From contributor R:
If you get the Excalibur, I suggest investing in a Master Plate and Super Bar to tune it. That reduces the tune-up to 10-15 minutes. You slap the plate on in place of your saw blade and set your rip fence parallel to the plate/saw blade with the Super Bar, a dial indicator on-a-stick, basically. Really quick and really accurate and easier than trying to tweak the saw table into alignment with the saw blade. Then all you have to do is square the Excalibur's cross-cut fence to the saw's rip fence, which I do with one of those big folding squares which are also really accurate, and you're laughin'.

From contributor D:
Contributor R makes a good point about having super accurate test gauges and such in your shop. I have several. As far as adjusting the crosscut fence parallel to the blade, I prefer a dynamic test, as the proof is in the pudding, so to speak. On the initial setup, to set the crosscut fence to the blade (my rip fence is set a hair open to the blade at the back end) after first using a framing square to get very close, I simply use a wide, scrap panel (usually 3/4 MDF) with one strait long edge and make a test cut, then observe the results using an accurate framing square, followed by micro adjusting the fence if needed. I test the fence alignment often (its fast, easy, and accurate) and particularly before any large runs, to ensure accuracy of the whole batch.

The initial (full day) tune up included removing some parts from my existing PM66, cutting a short section off the left end of my Beistmyer fence rail, drilling and tapping a few new holes to accept the Excalibur package, and then aligning the Excalibur rails, adjusting the bearings, adjusting the leg levelers to bring the top of the Excalibur sliding table close to parallel to the top of the PM saw table, and a few other adjustments necessary to tweak the top of the sliding fence to dead flat and parallel to the top of the saw table. All of this can be accurately done with a tape measure, a 48 level, and some careful attention to detail, which takes time took me a day, but a day worth the effort.

I bought the Festool Plunge saw setup with the track system - it works great.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
I use the pattern cutting way. Cut a giant contactors square out of a factory edge of a sheet of plywood. Sscrew it to your piece. Then attach a board to your fence. I use a 5" board with 2 1" holes drilled in it. Use f clamps to attach it to the fence. Put the board above the blade flush with the outside high enough to clear the piece you're trying to cut, but low enough for the plywood pattern to ride against it. I just made a 5'x5' coffee table. It worked great.

Comment from contributor B:

I have been using an Excalibur sliding table for the last few years and had variable results until I attached the far end of the inboard rail rigidly to my outfeed table, which is secured to the back rail of the saw. This means the rails are held along their length instead of just being attached by two bolts to the saw top. Now it maintains a square cut after some use, a definite improvement.

Comment from contributor J:
I use a Saw Trax panel saw. It's quick, easy and never goes out of square. Verticals make handling sheets much easier as well.