How to cut a plank diagonally on a table saw?

[mark]

How can I set up my table saw to cut planks diagonally so as to produce two long triangles?

mark

[Bill Wright]

First cut a plank diagonally so as to produce two long triangles. Discard one and use the other as a fence.

Bill

[F Murtz]

:)

[Andrew May]

Surely you don't mean use it as a fence. That will force the plank across the blade. What you mean is run it along the fence next to the board to be cut.

[mark]

[mark]

Not helping.

[newshound]

Use a hand held circular saw and a sawboard, with a second plank alongside the one you are cutting to provide a supporting surface. Or a suitable sheet of plywood.

[Bill Wright]

Yes of course.

Bill

[Bob Henson]

I fear you have a quite basic incompatibility involved. Most planks are made of wood, and triangles are made of steel - otherwise they go "clunk" when you hit them instead of a nice melodic "ting" noise.

[James Harris]

Would it not be difficult to keep triangular piece and plank being cut together for the full cut?

James

[James Harris]

Depending on what you want to do have you considered marking the diagonal and feeding that to the blade by eye?

James

[mark]

[GB]

You don't need that, surely? Just one long straight bit plus a bit of scrap wood tacked to the end. So that makes two sides of the triangle. You don't need a full triangle, just the outline, and two sides will do.

[mark]

That is the default method. I'm looking for a more efficient method.

mark

[Tricky Dicky]

Preferably using a slightly wider plank than the one you need to cut, nail or screw your plank on top set at the correct angle. A centre line on the g uide plank will help alignment, make sure none of the screws or nails are o n the saw line. Run the whole assembly along the fence which is suitably po sitioned to line up on the saw cut. It is essential that no part of the pla nk to be cut protrudes over the edge of the guide plank that is going to ru n along the fence.

Richard

[Jon Connell]

Using a taper jig, which you can make yourself like this:

[Tricky Dicky]

Taper jigs are only really useful on short pieces as the jig has to travel along the fence with the piece to be cut. The OP uses the term plank which suggests something long.

Richard

[michael adams]

For just one, ideally you need a piece of chip ply, mdf, etc the exact same size as your plank. Ripping it to width if needs be. If it isn't already, as it will be if you've just ripped it, set the fence to the exact width of this. Mark the diagonal on this, set your plank against the diagonal screw it to the chip etc and feed this through, overhang first. For balance purposes you may want to screw another long piece of waste underneath the overhang allowing plenty of room for the blade

You say planks which suggests you have more than one. If this is the case and they're all the same size - but you don't intend to cut them all you could one of of the planks instaed of the chip.

michael adams

...

[John Rumm]

A few options depending on how big they are and the angles required.

The first would be to build what is in effect a taper jig - a rectangular bit of scrap large enough that will let you clamp the piece to be cut to it, at the angle required. The scrap can then be run against the fence, and it will guide the diagonal cut. This technique is best for acute angles and smaller bits of stock.

If you were trying to cut an 8x4' sheet of ply, then I would probably admit defeat and use a sawboard[1] and a handheld saw unless you have a big table saw with lots of side and outfeed table space.

[1]

[stuart noble]

If the saw bed has grooves, a cross cutting jig is very useful for all sorts of things. No doubt there are details on the web, but essentially it's a lump of ply with two strips glued to the underside which run in the grooves. Freehand cross-cutting is asking for trouble IMO