what am i missing?

[Dennis Petrillo]

Hi All,

I jointed a board and then ripped it to length. I put a starret square on one of the lengths and mark a perpendicular line. If I put the square on the opposite length and mark a perpendicular line the two don't match. I even used different squares to check all with the same results.

My first thought was that the sides are not parallel so i must have measured the width a dozen times to make sure the sides are parallel and they measure the same through the length of the board.

Any thoughts would be appreciated.

Thanks in advance.

Dennis

[Tony Falotico]

Interesting Dennis, is the jointed edge straight or bowed? If the jointed edge is bowed, the ripped edge is also, this giving equal widths but none parallel perpendiculars (say that three times fast!).

Just a guess based on my history of acheiving bowed edges on the jointer untill I finally 'got the feel' for it.

[Roger Bailey]

Check your saw set up. It sounds to me like your fence is not square to the table. Lock your fence and check the distance from your miter slot to the fence on front and rear of your saw. My guess is it is out a little causing you to rip a slight taper cut.

[Lee DeRaud]

What you're describing can have several (or multiple causes):
1. Jointed edge isn't straight.
2. Square isn't.
3. Rip is not parallel.

You're saying you eliminated #2 and #3, so check #1 first with a long straightedge. But it would have to be way off over a short length of board to give the symptoms you describe.

To check #2, put it against the board with the leg facing to the left and draw a perpendicular line. Then flip it over so the leg faces to the right and draw another perpendicular line in the same spot: there should only be one line.

My money says combination of #2 and #3.

[Jim Becker]

Check the square on a known straight edge by drawing a line and flipping the square the other way around and drawing the line again. Do this from the SAME edge.

[Perry Holbrook]

Just a guess here. If you were ripping a narrow board from a wide one, the wood may have had internal stress and although you jointed the wide board straight, after you ripped it the stresses could have bowed it again.

Perry

[Dennis Petrillo]

Thanks for all the feedback.

Took all the info and checked all. Fence is squareto the blade, square is square. Went to measuring the width of the board again very closely and saw that it is SLIGHTLY off. I'm new to the TS. Just got a Bosch portable on wheels. Based on what I saw from the measurments, I'm wondering if it's my technique in feeding the wood to the table saw. There is not much table prior to the blade and it looks like I may have not registered the material against the fence properly until more of the material was on the base. I'll try some test cuts tomorrow.

Thanks again for all the replies.
Dennis

[Andy Fox]

Dennis, a featherboard was a big help to me with this.