Ok, I yesterday that I was off and rocking after having completed much of a cabinet over my long weekend. However, this has been a very frustrating experience for me. As always I broke down the large plywood sheets using a clamp-on crosscut guide and a circular saw. The only problem was that this time, I could not seem to get the pieces square.

Ok, so now I have analyzed it back to the break-down of the plywood. Now I just need to know how to aviod this the next time. My largest acurate square is 6”. I need something larger and I am thinking of either a drafting T-Square (which might get in the way of the clamping mechanism, or a drywall square. Man, now I only need a little while to think.

If any of you have any secret techniques or tools to use in getting things a little more square, let me know.

-- -- Rob Hix, King George, VA

## 2 comments so far

coloradoclimber

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548 posts in 2664 days

#1 posted 2630 days ago

If you have one straight edge and you want to get 90 degrees from it you can use the right triangle rule. The two short sides of a right triangle squared equals the angle side squared. Measure a distance

Aalong the known straight edge, measure up a distanceBfrom one end of the measurementAand measure at an angleCfrom the other end of the measurementA. WhereBandCcross is 90 degrees from the end ofA.Basically you are drawing a right triangle on the plywood. A simple set of numbers to use is 3 4 5. 3 squared + 4 squared = 5 squared. 3×3 = 9, 4×4 = 16, 5×5 = 25. 9+16=25. So a 345 triangle is a right triangle. Measure 3 feet along one edge, measure up 4 feet from the end of the 3 foot measurement, measure 5 feet from the other end of the 3 foot measurement and where the 4 foot and 5 foot measurements cross you now have 90 degrees from the 3 foot edge.

You can do this to any size. We use this technique to lay out floors, foundations, panels, basically anything you don’t have a square big enough to fit. If you have an odd size material and a calculator you can calculate the exact sides for any size.

To layout a big foundation we layout one side, then grab two big tapes, hook one tape at one corner, hook the other tape 30 feet over along the first edge, drag out the tapes crossing over each other until one tape reads 40 feet and one tape reads 50 feet and where they cross is 90 degrees from the first side.

Don

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2599 posts in 2773 days

#2 posted 2630 days ago

How about this (similar to above)?

-- CanuckDon "I just love small wooden boxes!" http://dpb-photography.me/

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