Sliding Table Saw Accuracy

Cabinetmakers discuss how to tune up a slider and provide tips for accurate cutting. January 13, 2009

I've had a Minmax S315 for about a year and a half now and have cussed this thing pretty much continuously since I got it. Then, after learning on here how to make a dust cut and true the panel before making the final cuts, things got a little better. But now they just don't make sense. User error is what this is looking like, but I do the same thing every time and I am getting mad.

I load the panel, make a cross cut dust cut first, move that against the cross cut fence, now make a rip dust cut. Now move my rip fence to my desired cut, put the panel over to the rip fence, lock it down, push it against the crosscut fence, double check then move the rip fence. Make the cut and usually I get right on. Now with the other panel, flip that from side to side so the factory edge is the next cut. I use the crosscut fence flip stop, position everything making sure it is nice and tight against the fence, make the cut and I am off half the time. Here is the kicker, I am off both ways, meaning if I were to adjust the fence, I would be going back and forth.

I am not stupid and have cut plenty on this saw, but it has never been magnificent. I don't know why I ever bought this thing. I probably would have been better off keeping my Unisaw and Excalibur. Can anybody help me out? This may be a question about should I get rid of it and look at something a little more user friendly, or can someone say "dummy, you forgot to do this or that"?

One thing I liked about the slider is the scoring blade. Not that I use a lot of melamine, but if I do, that would be nice to have. Is there another saw out there that might fit my needs better? I am a one man cabinet shop and do about 5 kitchens a year.

Forum Responses
(Cabinetmaking Forum)
From contributor E:
I bought the same saw at about the same time. One of the first things I did was square the crosscut fence to the carriage by using a large 3 4 5 triangle. Measure 6 foot across the fence, 8 foot down the carriage, and 10 foot for the diagonal. I had to adjust the set screw on the larger knob to square. Also on narrower rips I measure to the carriage front and back to get parallel.

From the original questioner:
Please explain the 3 4 5. How big was the square and how accurate? I know the 4 5 6 method, but could you explain in detail what you did? Also for the hell of it, on my last rip I kept the rip fence in place and got a true cut. I know you are supposed to move them after you get your measurement, but I am getting desperate.

From contributor J:
Mine never stayed square. Tried to use it, Minimax sent a tech from Atlanta, but one good whack of a piece of ply and it was square no more. Sold it for half of new within a few months. The worst part of it all is the guy I sold it to still complains to me about it and that was some years ago!

From contributor A:
Please explain the 4-5-6 method.

From contributor J:
Example 345. Start at x, draw a square line 3 inches, then draw a line perpendicular to x 4 inches along y, the beginning and ending endpoints will be 5 inches. I.e.: 4', 6', = 8'. Start with a square piece if panel, I use a 36 inch x 48 inch piece of ply and lower blade to just cut kerf on diagonal. If a panel is out over 48 inches it is definitely out over 96!

I will add that now that I have gone CNC and am taking delivery of another machine in two weeks, my big SCM320 will become a boat anchor in this economy!

From contributor P:
Skip the 3-4-5 triangle. Do a 5-cut test on a square piece. It's the grown-ups' method of squaring a cc fence. Once you've got the fence dialed in dead-nuts-on, check with a few more 5 cuts. Assuming reasonable temperature and humidity for the material, the results should be repeatable. If not, it's a saw issue.

From a safety standpoint, I'd advise against using the cc and rip fences together. In my shop, it's an either-or. I'll pull the rip fence way back to act as a gauge for repeated small cuts with the cc fence.

From contributor J:
Contributor P is absolutely right. We use our saw the same way. My goal was to answer your question, and our saw basically stays pretty square.

From contributor I:
Don't give up yet. I too own a WS315 and have had some struggles with it, but it seems to be working okay now.

Take an approximately square piece of board, say 3'x3'.
Number the edges clockwise: 1,2,3,4.
Put edge #4 firmly against the crosscut fence and remove about 1/4" from edge 1, to the right of the blade.
Rotate the panel 1/4 turn counter-clockwise and make a similar cut on edge 2 and continue counter-clockwise taking 1/4" or so from each of the four edges.
Now for the last cut, do as you started, placing edge 4 against the crosscut fence, and remove about 1/4" from edge 1.
Mark this strip 1A (subsequent strips cut from Edge #1 will be marked 1B, etc.).
Using a micrometer, measure the thickness of 1A near the leading end and near the trailing end.

The variation in thickness of 1A will indicate the extent of out-of-squaredness of the four 90 degree angles you have created. If the width of the strip at its leading end is less than the width at its trailing end, your crosscut fence is cutting less than 90 degrees. Conversely, if the width of the strip at its leading end is greater than the width at its trailing end, your crosscut fence is cutting greater than 90 degrees.

Suppose 1A measures .250" leading and .290" trailing, then:
(.290-.240)/4 angles= .010" per 90 degree angle over 3'.

In this case, the crosscut fence is cutting less than 90 degrees, therefore adjust your crosscut fence at the 3' mark by increasing the angle by .010".

Redo the process and check 1B in the same way. By trial and error you should be able to obtain +/- .005" accuracy on 3' (depends on how good you are and your patience, etc.). Once you have produced a (nearly) perfectly square panel, use the panel to check the squareness of the rip fence.

Another thing to check is clearance of the slider above the fixed table (allow about .010"). Very important: check the alignment of the blade and the slider - they should be perfectly parallel.

Remember that when ripping, the material should be lightly touching the rip fence and need not be aligned with the crosscut fence. Use a light touch when ripping to avoid banana cuts on long rip cuts.

Don't throw away the saw just yet. Any saw however cheap or expensive has to be set up and adjusted properly. This is an important skill to master and is one of the keys to product quality in our business.

From the original questioner:
Thanks for the responses. I have used the 5 cut for years, even back when I had a Unisaw with an Excalibur. I know the saw is tuned right according to the 5 cut method, and I use a 1/4" MDF when I do this.

My question to contributor I is, and I will feel really stupid if this is correct, when ripping a full sheet of plywood, you do not use the cross cut fence? My interpretation all along was basically the rip fence is for ripping hardwood and as a measuring device when cutting to the right of the blade. I believe that is why I always did an initial crosscut dust cut to make a straight cut to push against the crosscut fence, then make a rip dust cut. In saying that, I use this saw that way, I also now realize that the crosscut fence is exactly that. Please let me know if this is correct because in my thinking this seems to be more like an American saw than a European. Am I correct in assuming that you said when ripping, use the rip fence and not the crosscut fence? Because several times when I was cussing at this saw I was tempted and have before used the rip fence like I would a Beisemeyer fence, then went back to using the crosscut.

From contributor P:
I just had my Altendorf set up by the factory tech, and both sliding table (this isn't a function of the cc fence squareness) and rip fences were set just slightly away from square, so that you have just the slightest buzz as the piece passes by the trailing saw teeth.

I use my rip fence for all long-cutting functions, like panel busting, strip cutting, hardwood ripping.

From the original questioner:
Would someone please go over this from start to finish for sheet goods? The way I am doing it now is as follows; crosscut a small strip (dust cut), now rip a small strip (dust cut), now move my rip fence to 23 1/2", move plywood to rip fence, lock the piece down, squaring it to the crosscut fence, move the rip fence so there is no pinching, make the cut, now flip the piece over with the factory cut now facing the saw blade, use the crosscut fence stop set at 23 1/2", rip that piece. Most of the time I end up with 2 8' sheets x 23 1/2".

From contributor P:
This is how I do it - not that it's the only method or even a correct one.
1. Panel goes on the sliding table, 8' dimension to the blade.
2. Trim cut full length using the slider.
3. Rip to width using the rip fence, no involvement with cc fence.
4. When everything's ripped to strips, slide the rip fence away, and crosscut to size, using the cc fence, no involvement with rip fence.

Typically, I edgeband full-length rips, then crosscut to size. It'd be interesting to hear how others do it!

From contributor M:
This is how I do it.
First, lay the long edge against the back of the crosscut fence. Trim the short edge.
Rotate the fresh edge to the crosscut fence. You now have a long egde running along the blade. Trim this edge. You now have a squared edged.

When you use a factory edge against the crosscut fence, it is only as accurate at that edge. When you cut fresh edges, and rotate them against your crosscut fence, you know it is square. It only takes a minute more to square up a side, but if you have a saw that is capable of .005 over 10', then it is a good practice.

From contributor I:
I must concur with contributor P. My approach to the sliding table saw is identical to his.

If W>L then crosscut

if L>W then rip.

And when ripping, use the slider to move the panel, but your reference is off the rip fence, not the crosscut fence.

From contributor P:
I'm not particularly looking for square at that point - just want a clean edge to put against the rip fence so I can get a parallel rip. I take care of the factory end when I crosscut - overcut my first piece for length, flip it, then trim off the factory edge to get it to the desired length.

From contributor M:
The only way that you can ensure that your edges are parallel is to make sure the edge against the crosscut fence is straight. If you have some defect in the short edge, up against the fence, then your rips may be off.

For example, if you have a defect in the first 12" of your material. You run it through, but it is sitting 1* off the fence. Now you move your material over, and the defect is no longer there, and your material is flat against the fence. If one of these cuts is off by .25*, your rip will be out of parallel by more than 1/2" (.534). That's why I say that it is important to make a head cut. And when you do, you don't have to recut all those rips to make them square. You just know that they are already square, and you cut to length. You go from making 4 small crosscuts to 1 large crosscut.

From contributor P:
Head cut's still not important. Even if my factory end is badly out of square, as long as I'm getting a dead-straight long-edge trim (using the sliding table), my subsequent rips (with rip fence) will be parallel on the long edges, just not square to the ends. Since my stuff gets moved to the bander before cutting to length, I'm happier having the factory ends - since they're sure to be cut off, any damage in stacking, bumping on the floor, etc., won't matter. Your mileage may vary, but it works for me!

From the original questioner:
If you use the crosscut fence for everything like I was doing the head cut technically does not matter, but on more than one occasion I have noticed factory edge damage that could not give me a flat surface to push against the fence, so I went back to making the head cut dust cut.

To bring up a point that was made regarding using the rip fence to rip... I just tried this, taking a sheet that I had already cut down to 23 1/2" now trimming off 1/4". This takes the sheet completely off the slider. This is not easier; I would have to put a roller in front of the saw like an infeed roller. That is a pain and would have always just cut this down using the crosscut fence and normally it comes out, but doesn't on occasion. That was my complaint. So for you guys that use the rip fence to rip, how do you handle this problem? Or is it a problem when you are ripping a whole sheet down? Is there enough material to catch the slider and keep the sheet up?

From contributor P:
It's a little unwieldy, but not bad - I almost never use an infeed roller with panel stock. Like everything else, there's a learning curve, and this one isn't very steep. I'm typically busting 23" or 11" rips (applied backs!), so there's usually something hanging on the sliding table.

To me, it's a problem trying to make that rip with the cc fence. Whatever error you've got in the placement of your head cut against the crosscut fence will be magnified in that rip, i.e., a .002 error in a 24" wide rip becomes .008 by the end of the 8' pass.

From the original questioner:
I agree with the smaller the sheet stock the more room for error definitely. For wall cabinets I do use the rip fence because it is more accurate. Going back to the headcut issue it is easy to figure out. Just take a notebook or book - something rectangular to mimic a sheet of plywood. Now move that through an imagination saw and go over the cuts. If you do it the way I do it is my belief that a headcut is unnecessary, however, like we were talking about before, the factory edge is sometimes too bad to deal with. I cut a sheet down once and was way off, went over what was done wrong and it was a bad factory headcut! This is why I do a headcut now, simply because when I push a sheet against the crosscut fence, I don't want to see any gaps at all.

From contributor M:
The beauty of the carriage is that it can be used for almost everything. When you use the rip fence to make long rips, you basically have a glorified tablesaw. I used to use my cc fence for rips, and consistently got rips that were within .003. An Altendorf F-series can hold these tolerances. And it is a heck of a lot faster than using the rip fence for rips. It does take practice, though.

I put a roller in front of the table. But again, use the carriage (cc fence) as much as possible. The slider was designed to do as much as possible on the left side of the blade. That is why the carriage is so accurate. There are many possible ways to use this machine - I won't argue that. But when you use the carriage correctly, it makes things more efficient.

I know it is a small matter, but when you use the rip fence, the material has a very small amount of fall-off. When you set your fence up, the rear of the fence is to be about .005 away from parallel from the blade. So when you push your material through, it is slightly skewed. The material on the fence side touches the front of the blade, while the material on the left of the blade touches the front of the blade and the rear (heel) of the blade as it passes.

When you use the crosscut fence, the material passes both sides evenly, and you do not get a recut on the back side. The carriage really does have more function than most people use.