Cutting Plywood square

jaguar36

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Jul 19, 2011
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I've used my TS55 on a few projects now and always seem to have difficulty getting the plywood pieces to be perfectly square.  I've been using a 12" speedsquare to square the guide rail and I try to check everything a few times before making the cut, but somehow I always end up with a few pieces that are out of square by 1/16" or even more.  Does anyone have any tips on how to do a better job?
 
When i first got my MFt and ATF 55, I tried, with some success, to cut plywood sheets to dimension right at the tailgate of my truck.  It worked to a point, but i found i could get enough off that I might occasionally have to "redesign" a little.

I now make cuts just a tad oversized and breakdown the sheets at the truck, bring them into my MFT and make my cuts to dimension there.  It saves a lot of time and far less "redesigning" time lost.  In the long run, there is less waste even tho I need to trim once inside the shop.
Tinker
 
The MFT is quite useful if you're cutting plywood down to typical cabinet dimensions. You need to rip the plywood to dimension first (don't bother squaring the sheet just rip a clean edge to reference off of).  Then crosscut using the MFT with the attached fence and guide rail. Using the adjustable stops on the MFT fence helps make repeatable cuts go really fast.

 
Use the Festool System.

1. Use the parallel guides to cut strips out of your sheet goods.

2. Square up one end on the MFT.

3.  flip work peace end for end and make your second cut to length.

If I follow this process I will get square work peces out of my sheet goods -- every time. If I short cut the steps, thing start to get out of square.

Plus get a bigger square, this is the one I use (Framing square) to square up the MFT. I have also used the large square with the 1400mm Guide rail to make square cuts with sheet goods.
 
Another method is:
1-TS 55 and rail to cut one straight edge on the 8 foot side.
2-Use Woodpeckers 660 mm Precision Square to square your rail on the first cut

You then have to side perfectly square to do your cuts. I was having problem till I got a quality square of a decent size. The above woodpecker square is my go to instrument when cutting down plywood that doesn't fit on the MFT.

Bruce
 
Like Greg and Bruce, I do own 2 of the Woodpeckers 660mm precision squares. They are very nice to use.

However, decades before they were available I had precise framing squares. There is an old fact of geometry:

Establish a straight edge. Take a square. Place it in the straight edge and draw a line using the perpendicular leg of the framing square. Then flip the square so the reference leg goes the other way on the straight edge. If the other leg lines up with the drawn line, that square is accurate.

In practice long ago I first went to an art supply store to buy a 30" x 40" piece of multi-ply art board. That was not very heavy and a product not sold in hardware stores. I carried it with me to 'audition' the supply of large framing squares. I would take one, try the test and if it passed, I would buy that square. If not, I would audition another, and so on, until I found an accurate square. The first time I tried that the hardware store had 4 26" framing squares in stock. The first one I tried passed the test. So did the second one. I bought both of those and still own them 60 years later. Minutes ago both passed the same test.

Yes, in use there advantages to using the Woodpeckers squares, because the shorter leg functions like the thick leg of a tri-square.
 
jaguar36 said:
I've used my TS55 on a few projects now and always seem to have difficulty getting the plywood pieces to be perfectly square.  I've been using a 12" speedsquare to square the guide rail and I try to check everything a few times before making the cut, but somehow I always end up with a few pieces that are out of square by 1/16" or even more.  Does anyone have any tips on how to do a better job?

I think the key to your problem is consistency. Most of your cuts are accurate which suggests your measuring tools are well-calibrated. Have you tried clamping the rail in place before making the cut? Perhaps it is shifting slightly?

 
I took an aluminum yard rule and cut off the front end (starting at 1") to match the width of the guide rail. In my case, it was something like 7 9/32". Then I attached to the ruler one of those stops that are used to fix a distance when using a square to mark stair treads. Slide the stop to the desired measurement, tighten and push the guide rail with the ruler until the stop hits the edge of the piece to be cut. Repeat on the other side of the guide rail, and if it is a long span, in the middle until the guide rail is equidistant along its length from the edge. Considering the stopped distance on the ruler and the width of the rail, your cut should be pretty exact. Oh, and use the clamps...

I think that the precision of a square over a long span is iffy.

I got this from an older gentleman who has since died that that a web site and did demos of festools in various projects and how to use the tools. Works very well.
 
pugilato said:
I got this from an older gentleman who has since died that that a web site and did demos of festools in various projects and how to use the tools. Works very well.

I believe that would be our old friend (RIP) John Lucas who did Work Shop Demos.  His work can be seen at John Lucas - Work Shop Demo Website

Lots of good ideas here.

Peter
 
I cut one clean edge. Use paraleel guides cut ply to width. Next place ply on MFT cut to length.

I use the Pinnacle square to square up the cross rail on the MFT and the fence.

Note: I connect 2 1400 rails to rip the ply to width.

The ply is only 1-2 mm out over the entire length of the 8 ' ply.

I couldnt get that on my Table saw.

You could also go to U Tube and search for Ron Paulks Ultimate Work Bench which some folks have made and are happy with.

He sells the plans for it for something like 5 bucks notsure exactly)
 
Are people finding that the ply they are buying isn't square? I worked in a mill years ago and that stuff was dead square. The ply I get locally and in Eugene is pretty much square too.

I agree with the other posters that a 12" speed square doesn't have enough arm to be very accurate. Interestingly enough I have some pretty high end T-Squares that aren't square [eek] - good enough for drawing I guess.  [big grin]
 
Anyone know where to find one of the Woodpeckers framing squares? I tried their website and they aren't available.
 
Birdhunter said:
Anyone know where to find one of the Woodpeckers framing squares? I tried their website and they aren't available.

Yes, they were one of their one time tools.  You might want to give them a call and see if they have any stragglers around.

Peter
 
Peter Halle said:
Birdhunter said:
Anyone know where to find one of the Woodpeckers framing squares? I tried their website and they aren't available.

Yes, they were one of their one time tools.  You might want to give them a call and see if they have any stragglers around.

Peter

They even have a place on their site where one can ask that any One-Time Tool be brought back into production.

[smile]
 
Search the jigs board for Steve Jones' cutting table. Even if you don't build the whole thing, (I built a surface that I can use on a shop cart, and then put away) he goes into how to align the setup to cut square.
 
I had a similar issue. For me the answer was to work slower to work faster. That may sound strange but by taking the time to measure, mark, clamp and then check and cut I saved a lot of re-design time.

I know that I can make cuts without clamping the rail, I do it often but I found on those critical pieces if I clamp I have no issues.  The method of work that works best for me is to cut about 3/16 off the factory edge to give me a clean and straight edge. From there I measure and mark in 3 places for my long parallel cut. Clamp, check, cut. Cut to length on the mft. Everything turns out square and true every time.

By the way I found that making  a story pole made a tremendous improvement in the accuracy of the entire project. I began using a 1x piece of scrap wood as my first story pole. Halfway through that first project with the story pole I could already see that this was something I had been missing I quickly ordered the Woodpeckers Story stick Pro http://www.woodpeck.com/storystickpro.html.  This makes things really nice throughout the entire project from laying out 4x8 sheets to making sure all the drawer slides are at the correct height. This is one of those tools I wish I had figured out sooner. It sure saves a lot of re-engineering. I also use Fastcaps story pole tape measure. That really stops those little mis-read measurement mistakes.
 
Yes, I have one of those story sticks. Brilliant tool. Amazing for aligning drawers, shelf widths, even carcass sides under 48".

 
polarsea1 said:
Are people finding that the ply they are buying isn't square? I worked in a mill years ago and that stuff was dead square. The ply I get locally and in Eugene is pretty much square too.

I agree with the other posters that a 12" speed square doesn't have enough arm to be very accurate. Interestingly enough I have some pretty high end T-Squares that aren't square [eek] - good enough for drawing I guess.  [big grin]

I check all my sheets for square and find that most are, and some aren't. To check, I use a framing square that I regularly test for square using the test described by ccarroladams above.

Re:  drafting T-squares:  they're meant to provide a consistently parallel reference for your set squares, so it's not a good idea to trust them as a square.
 
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