Page 1 of 2

Ripping a 22.5° bevel.

Posted: Wed Jan 15, 2014 2:45 pm
by beeg
I'm working on a project, a serving tray. That the sides are 5/16" thick, 2" wide and 16" long. I have to rip a 22.5° bevel on one edge. HOW wood you do this SAFELY?

Posted: Wed Jan 15, 2014 3:25 pm
by wa2crk
Beeg.
Set the table to 22.5 deg. I use a Wixey cube to set the table. Then position the rip fence so that the saw blade teeth just touch edge of the piece where the teeth break through the top of the workpiece. Then rip as you normally would. The offcut will be on the upside of the blade but should be very small and will not really be a problem with kickback.
I generally rip my pieces to almost the finished width then make the bevel cut and finish by putting the top of the bevel against the fence to make the final cut when the table is returned to 90 deg.
Bill V

Posted: Wed Jan 15, 2014 6:09 pm
by dusty
I can't answer your question. Need input.

Which of the following represents what you need when done?

[ATTACH]23776[/ATTACH]

Both are cut at 22.5° depending on how you measure.

The one on the left can be done as Bill just described. I would prefer, however, to cut the bevel in an over sized board (say 3 1/2" and then rip it down to finished width.

[ATTACH]23777[/ATTACH]

This is the way I would rip it.

Posted: Wed Jan 15, 2014 6:14 pm
by charlese
beeg wrote:I'm working on a project, a serving tray. That the sides are 5/16" thick, 2" wide and 16" long. I have to rip a 22.5° bevel on one edge. HOW wood you do this SAFELY?
Start over again if necessary. Make a board 5/16" thick (or thicker), 4 1/2" wide, 17" long. Rip your bevel on each long (outside) edge. Now rip the center to desired width and sand or plane to proper thickness. Last thing is to cross cut to length.

Posted: Wed Jan 15, 2014 6:27 pm
by reible
Asking this another way, is the bevel on the 2" side or the 16" side?

If on the 2" side then I go with the miter gauge and stand the piece up.

Ed

Posted: Wed Jan 15, 2014 6:55 pm
by beeg
dusty wrote:Which of the following represents what you need when done?

[ATTACH]23776[/ATTACH]

It's your pic on the right or it's along the length of 16".

Posted: Wed Jan 15, 2014 7:06 pm
by dusty
beeg wrote:It's your pic on the right or it's along the length of 16".
Tilt right as shown in the second depiction 22.5°.

I would make a ZCI with the table tilted just to be safe.

Add a sacrificial fence and cut away.

Posted: Wed Jan 15, 2014 9:19 pm
by edflorence
My experience with these bevels along the long edge is that the cut-off piece, which will be on the "uphill" side of the blade is, if wide enough, restrained by the kickback pawls and the blade guard, so kicking back of the cut-off should not be an issue, unless the cut-off is very narrow in which case it might be thrown back. In that case, you might consider ripping the bevel with the jointer.

Posted: Wed Jan 15, 2014 11:31 pm
by JPG
Band Saw???????????????

Posted: Thu Jan 16, 2014 7:07 am
by BuckeyeDennis
IIUC, you need to make the acute bevel cut, as per Dusty's second illustration. In which case:

If using the table saw with a sacrificial fence, it seems to me that you would need some sort of guide for the top (square) edge of the board. I say this because, as you near the end of the cut, you would have cut away most of your support on the edge against the main table. How you would reliably hold the board against that top-side guide, I don't know.

Instead of ripping on the table saw, how about making a rough bevel cut with the bandsaw, or just rip it to 45 degrees on the table saw to remove most of the waste? Then finish the bevel with the SS in vertical mode, using a rotary planer (e.g. a Wagner Safe-T-Planer). It adds an extra step to the process, but it can be done safely and accurately.

You might be able to use a conical sanding disc instead of a rotary planer, but I'm not sure if you could get the required clearances. Or you could probably find a panel-raising router bit that would work.

EDIT: Aha! I just realized that Dusty proposed a table-saw setup that does not actually cut away the acute edge of the bevel. In which case, my concern about cutting away all of your bottom-side support is unfounded.