What is the best way to square a Frame?

[Larry Mathews]

I am making an 75" x 40" frame with 2X4s and want each corner square.  Now  if I was using nails I would place one in each joint then measure the diagnols and square it up before putting more nails in the joint.  The Kreg system will pull the joint tight.  So what is the best way to square this frame using the Kreg system to join the 2X4s at right angles?

[Jay Boutwell]

Larry this is the fast method that I would use, do the diagonals and hold it in position with temp diagonal braces until you finish your permanent screws or nails then remove.  put two fasterners in each end of the diaagonal braces to prevent it from racking while you apply the permanent fasteners.
Larry Mathews said:

Jay & Jens,  I have used the diagonal method before with one nail in each corner until I got it square. In that case as long as it is not finish work if my cut was off a 16th it did not matter.  With using the pocket holes it seems to me the screws will pull it back out of alignment if the cuts are not dead on.  John's suggestion of using shims might solve that problem.  What do you think?  Of course as we all know the real answer is square cuts.

[Gary roofner]

Good old Pythagorean useful tools to prove 90 degree angle.

[Michael Campbell]

I always use the 3-4-5 for large squares,   at 75x40.  If you measure 52" on the 75" side,  and 39" on the 40 " side.  the diagonal will be 65"  get it there and screw a 1 by to hold it in place... hope this helps  I used this to square 40 feet long with a 100' tape..  math is your friend   good luck

 

[OUTSIDER]

the same way as if your nailing should work.I use a jig for corners,but that is set up for 1x4x48 stock.You could always use a large square on your work and clamp it in place.My take on square corners is have your work cut straight and you will get good corners 99.99% of the time.

[Gary roofner]

Pythagorean Theorem for all right triangles a² + b² = c²   

In our example a= 3 or 9 b=4 or 16    9 + 16 = 25 square root of 25 is 5 or c=5. For the 3-4-5 triangle will be a  90 degree 60 degree 30 degree right triangle

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

^I

[Bob S]

I'm in no way trying to argue, but a 3-4-5 triangle is not 30-60-90 degrees. 

 

It's more like 36.9-53.1-90 degrees. 

 

You can figure it out with a trig table.

[Gary roofner]

I stand corrected you are right.  I checked out my memory is wrong. I'm now trying to remember the significnce of the 30 60 90 right triangle.

[Micheal Denine]

make a jig for your saw, and use a framing square in the corners also use the 3' 4' 5' rule . measure one peice 3' the adjoining peice 4' and the diagonal between the two peices will measure 5'. if it doesnt then adjust your wood until it does.

[Ken Darga]

The 30, 60 & 90 angles, are one of the drafting/drawing triangle tools.

Gary roofner said:

.......................I'm now trying to remember the significnce of the 30 60 90 right triangle.

[Steve Bennett]

Have a table saw accident, win millions and have someone else worry about it LOL. sry couldnt help myself