Breaking down sheet goods - Square

[Greg Peterson]

I am making a bass cabinet for a bass player out of 3/4 BB plywood. The old cabinet is simply not worth the time, money and effort to rehab.

What measuring methods or devices do you guys use to ensure perpendicular angles on your layouts.

The several times I have broken down plywood I have not required a high degree of precision. And every time I have struggled trying to get 90 degree angles dead on. Always slightly out of square.

I have clamp guides for both 4 and 8 foot lengths of sheet goods. It's the layout that is problematic.

[Ken Fitzgerald]

Greg....I use the pathagorean theorem......IIRC.....3,4,5 right triangle......measurements....and a straight edge guide.

[Karl Card]

Good question. I was also looking for a good sensable answer also.

[Reagen Ward]

I do it poorly. I clamp a purpose-built straight-edge to the sheet, get out the speedsquare, measure, measure again, measure with a T-square, maybe get out a drafting t-square, and then cut while chanting 'please be square' over and over. Or, I just use the table saw and ask someone to act as outfeed handler.

I'll be watching this thread, as I'm perilously close to investing in a (much too) expensive track saw system like DeWalt or Festool. I don't want a panel saw, and if I'm going to buy something over $100, I want the saw to ride in a track and have a zero clearance plate.

[Jerome Hanby]

I do it poorly. I clamp a purpose-built straight-edge to the sheet, get out the speedsquare, measure, measure again, measure with a T-square, maybe get out a drafting t-square, and then cut while chanting 'please be square' over and over. Or, I just use the table saw and ask someone to act as outfeed handler.

I'll be watching this thread, as I'm perilously close to investing in a (much too) expensive track saw system like DeWalt or Festool. I don't want a panel saw, and if I'm going to buy something over $100, I want the saw to ride in a track and have a zero clearance plate.

I've got both, and the Festool system is definitely easier to use (and that saw is just sweet), but you can get the same functionality out of the PSI Portable Panel Saw system. It works with your circular saw (most brands, some bases might be problematic) and runs about $150 on Amazon. I use mine with my Hitachi circular saw from Lowe's (it lives in the PPS carriage) and does a good job. I still use it when I have long cuts to make (I haven't broken down and bought the long Festool rail yet).

[harry strasil]

http://www.sawmillcreek.org/showthre...ghlight=square

[David Hostetler]

I measure, measure, measure, measure... Simply put, I measure, and mark just slightly proud of where I want to be, break it down to rough size, mark the side just cut, and move to the table saw for accurate final dimensioning. with some time, and effort you CAN make accurate cuts with a circ saw and a cutting guide, it just takes a bit of work...

You can make a cutting guide with a T-square style end to keep your cuts square. I believe FWW has a video to show you how...

[Andrew Kertesz]

Similar to the Festool method, you need to have two edges parallel to each other. Don't depend on the factory edge. Using a straight edge make one cut along the length or width depending on your cut diagram for maximum yield. Once you have two edges parallel making the rest of the cuts square should be a walk in the park. Your first cut doesn't have to be perfectly straight according to the size of the plywood. The second cut is what matters making sure it is parallel with the first.

[Matt Meiser]

I just work off one edge and use my Festool saw and rail. To square, I bought a big (12"?) speed square which works great, is repeatable, and strong enough not to flex. I just push that against the back side of the rail and the chosen edge.

[Reagen Ward]

I've got both, and the Festool system is definitely easier to use (and that saw is just sweet), but you can get the same functionality out of the PSI Portable Panel Saw system. It works with your circular saw (most brands, some bases might be problematic) and runs about $150 on Amazon. I use mine with my Hitachi circular saw from Lowe's (it lives in the PPS carriage) and does a good job. I still use it when I have long cuts to make (I haven't broken down and bought the long Festool rail yet).

Awesome suggestion! I wasn't aware of that product, but I do like PSI. Thanks!

[glenn bradley]

I use a shop made guide for the saw to get a reference edge. Then I rip to width and use a sled to cut perpendicular ends. I have an oversize sled for large panels as you may encounter.

[Ray Newman]

For more then a few years, I broke down plywood with a PC Trim Saw. I found -- the hard way -- that the quality of the cut also depended upon the quality of the blade. Sometimes the cuts were not square to the face, ragged edges, out of square, etc.
Remedies:
--Purchased a “dedicated” plywood blade.
-- Applied some stick-on sand paper to the shop fabricated jig to prevent the jig from moving ever so slightly.
-- Screw type clamps held the jig firmly in place.

[Bill Miltner]

Can anyone tell what the difference is between the PSI Portable Panel Saw System (PSS-2) $154 and the one on the Penn state website for $99 (plus $17 shipping)?

[Greg Peterson]

Very clever guide Glenn.

Could you provide some particulars and/or pictures on the cross cut sled? It looks interesting.

[Peter Scoma]

My father was given a square from an old glass shop that is about 5ft on its longest edge and 3 feet on its shortest. Its all boxwood with brass fittings. 100 years later its still very accurate.

PJS