Accurate 90° cut on plywood - how?

[Mark Gibney]

How can I make an accurate, repeatable 90° cut on plywood that is too wide for my table saw sled?

I don't have a sliding table saw, I do have a Festool track saw. But not their MFT table.

When I google to find a jig it keeps taking me to Pinterest pages, which I am not a member of, and are of no use to me. Highly aggravating.

If this question has been answered on a previous thread I'd appreciate being pointed in that direction.

Thank you, Mark

[JAY FOSTER]

Just use your Festool track saw, you don't need their MFT table. Set the depth of cut accordingly and place some scrap wood underneath the plywood and cut it on the floor or workbench. I have seen some people but a large 4x8 sheet of foamboard (insulation) to place under the plywood as a sacrificial piece.
1:05 https://www.youtube.com/watch?v=BSF9fKgwGpc
https://www.youtube.com/watch?v=SE8Cjfb7VY8

[David Bassett]

How can I make an accurate, repeatable 90° cut on plywood that is too wide for my table saw sled?

I don't have a sliding table saw, I do have a Festool track saw. But not their MFT table.

When I google to find a jig it keeps taking me to Pinterest pages, which I am not a member of, and are of no use to me. Highly aggravating.

If this question has been answered on a previous thread I'd appreciate being pointed in that direction.

Thank you, Mark

To search this site, add "site:sawmillcreek.org" (without quotes) to the search terms with Google (and probably other search engines.)

As far as a quick answer, I'd say with your track saw and *VERY* careful layout.

[George Bokros]

If you square the track saw track to the edge you should get a 90* cut, you do not need a MFT to do so. I have a Eureka Zone track saw and use a support on saw horses and make 90* cuts on ply all the time. I do use the clamps to secure the track to the ply so it does not slip while cutting though.

[Jim Becker]

Just measure carefully and the track saw will do the job accurately and safely

[Jim Morgan]

If you square the track saw track to the edge you should get a 90* cut, you do not need a MFT to do so. I have a Eureka Zone track saw and use a support on saw horses and make 90* cuts on ply all the time. I do use the clamps to secure the track to the ply so it does not slip while cutting though.

+1 on the EZ track. I use a framing square to line it up before clamping & check afterwards. I have a Woodpecker, but any framing square tuned to 90 degrees works. Of course, this is not for high-volume workflow. If that's what you need, you might look into a panel saw.

[JAY FOSTER]

Yes, I forgot to use a square, either a large speed square - https://www.amazon.com/Swanson-Tool-...re+Layout+Tool, or even a large drywall square - https://www.homedepot.com/p/Empire-4...0-48/202035306

[David Bassett]

Yes, I forgot to use a square, either a large speed square - https://www.amazon.com/Swanson-Tool-...re+Layout+Tool, or even a large drywall square - https://www.homedepot.com/p/Empire-4...0-48/202035306

Or, (especially if this is a one-off deal,) go a little slower and just measure the diagonals, corner to corner, of your layout lines.

[Bryan Lisowski]

One thing to add is to do a squaring cut with your track saw. Plywood isn't always square from the factory, so you may need to take off an 1/8" from the factory edge and then do your cuts.

[Lee Schierer]

Factory edges and ends of plywood are nearly perfectly straight and at 90 degrees to each other. Use a second full or partial sheet of plywood aligned with the edges of the piece to be cut to align your track saw fence at 90 degree so the blade will cut the sheet underneath at the correct location.

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[Alan Lightstone]

I use a large triangle and my Festool track saw. Works just fine.

[Simon MacGowen]

How can I make an accurate, repeatable 90° cut on plywood that is too wide for my table saw sled?

I don't have a sliding table saw, I do have a Festool track saw. But not their MFT table.

When I google to find a jig it keeps taking me to Pinterest pages, which I am not a member of, and are of no use to me. Highly aggravating.

If this question has been answered on a previous thread I'd appreciate being pointed in that direction.

Thank you, Mark

Are you willing to invest in order to achieve your goal?

If not, skip the next link:

https://www.youtube.com/watch?v=AmNyPvsfSCo

No other squares can match this jig and no other ordinary methods are as quick as it to get the same result.

I am not related to this company but my club fellows highly recommend it.

Simon

[Malcolm McLeod]

How can I make an accurate, repeatable 90° cut on plywood that is too wide for my table saw sled?

I don't have a sliding table saw, I do have a Festool track saw. But not their MFT table.

When I google to find a jig it keeps taking me to Pinterest pages, which I am not a member of, and are of no use to me. Highly aggravating.

If this question has been answered on a previous thread I'd appreciate being pointed in that direction.

Thank you, Mark

Since you have the track saw, the cutting aspect of this seems to be covered (as others have stated). If you're worried about layout and getting the angle just right, use the 3-4-5 rule:
Off of a corner, accurately measure 4' across and mark the base line. Measure up from that corner 3', and at the same time measure the hypotenuse at 5' (from your mark to the 3' vertical). Result is perfect 90deg corner. If 'feet' is too big, use any common convenient multiple; i.e. 4" , so 3 x 4"= 12" hgt, 4 x 4" = 16" base, & 5 x 4" = 20" hyp.

I'm sure you can web search for 3-4-5 triangle and/or Pythagoras' Theorem.

[Jacques Gagnon]

+1

Some form of trammel (or story stick) can be used instead of a steel tape; the principle remains the same: 3-4-5. This is the triangle that Alan refers to (#11).

[Mark Gibney]

Thank you all for your feedback. I use the 345 layout all the time, but I want something faster for when I need to make a lot of cabinet boxes.

Simon - that TSO aftermarket jig in the video is exactly what I could use. Have you used it? Is it accurate?

Another route is go is to get a cheap panel saw like what Rockler or Milwaukee sell, but these tend to have a bad rap unless you go to the high end expensive units. However, if it's set up square and used just for cross cuts it might remain square.

There's a fairly rough looking one locally on craigslist for $325. Any opinions?

https://losangeles.craigslist.org/ws...456361930.html