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+-- Thread: out of square half lap (/showthread.php?tid=7169826)
out of square half lap - b-bob - 12-16-2015
my inside measure is the same top and bottom and side to side maybe a 1/16 off but my diagonals are off about 1/2 inch, this is a face frame with half laps, face fram 35 1/4 x 28,any ideas why? bob
Re: out of square half lap - Edwin Hackleman - 12-16-2015
If you are measuring the top to bottom and side to side at the center of the face frame, then your frame is a quadrilateral but not not a rectangle.
Re: out of square half lap - Bibliophile 13 - 12-16-2015
Yep, that can happen. Tap the long corner to put it back to square.
On half-laps, the first critical part is to make the shoulder exactly square to the edge. The second critical part is to make sure the mating edge is properly jointed. If there's any snipe, the joint will want to pull up out of square.
Re: out of square half lap - mike4244 - 12-16-2015
Edwin and Steve are correct.How are you machining the half laps?
If you are sawing the half laps ,use a stop so each joint will be the same length for each side.Make sure the joint is square.If the 28" sides are exact same length and the 35-1/4" sides are the same then you can measure across the perimeter diagonals to check for square.You may be able to re-cut the half laps for square if needed without changing the dimensions too much.
mike
Re: out of square half lap - Routerman - 12-16-2015
Angle error. at 10' (1/6th of a degree), the width parallelism error at 12" = .035"
Miss that right angle x 1/2° and you're out a mile.
Your tool to measure the right angle = ?
That is , how well do you know that angle?
And how parallel is your stock?
Re: out of square half lap - Edwin Hackleman - 12-16-2015
One other thing. Before making any half lap joints for a rectangular face frame, make sure that the opposite sides are exactly the same length. I joined these face frame sides with half lap joints:
Six half laps altogether. In fact, I do not think there is a nail or screw in this entire cabinet.
Re: out of square half lap - Zack Butler - 12-17-2015
Check your cabinet before you fix the frame. With any luck, your cabinet isn't square either and it will fit.
Re: out of square half lap - Jonny Rocket - 12-17-2015
Zack Butler said:
Check your cabinet before you fix the frame. With any luck, your cabinet isn't square either and it will fit.
Two wrongs do make a right!
Re: out of square half lap - b-bob - 12-18-2015
I did all over again and it came out a lot better,
thanks for all the tips,
Bob,