Can I cut an acute angle, mid-stock with a mitre saw?

Question

I want to make several 25° acute point cuts on long thing stock. The following is just an example:

Before you tell me to bust out a hand saw: I've got ten bits of wood to cut at this angle and they're going into a big lap sandwich. They have to both be exact and consistent. I'm not yet good enough to do that by hand. I know the technique for good cuts, I'm just physically incompetent. There should be no shame in admitting that, but the comments don't want to seem to let that go.

So again, my focus here is consistent accuracy and (and it not take all day).

My mitre saw is usually the first tool I'd turn to for cross-cutting a thin bit of stock... But most mitre saws can only cut 45-90° cuts. The angles written on them and things like mitre gauges are 90°-offset).

That said, I could use a square block to re-offset against the fence. This would work fine for cleaning up a rough-cut end but there wouldn't be space for the perform a cut halfway down a bit of stock (as pictured).

I do also have a number of other tools with mitre gauges (table saw, band saw, router table, etc) that could be re-offset with a square block. The bandsaw has a similar "gets in the way" problem with long stock to the mitre saw fence, and the table saw is currently buried under a pile of rubbish.

Since opening this question, I made rough cuts by hand and cleaned up with the mitre saw, but it seemed very... Hacky. Is there a better way do to this?

Answer 1

You can clamp the piece to be cut along with a straight edge clamped parallel to the cut such that your circular saw will cut the line. Assuming your saw is set up squarely, you will be in a position to achieve an excellently square and straight cut at precisely the angle you set up with the straight edge.

Alternately, if you have access to a band saw, then that could be used with an adjustable sliding fence in the t-slot on the table or an easily made fixture with an angled block to achieve a good result in a similar fashion to what one might do on a table saw.

Yet another method would be to use a clamped straight edge as a fence and using a handsaw. The fence, a nice square piece of stock, perhaps a bit taller than one necessary for a circular saw is clamped right next to the line and the hand saw gently held against it as the cut is made. There are a number of ways to keep the saw in line with the fence, the simplest being using ones knuckle, fingers or even a block of wood to keep your hands out of the way. A block of wood is safest and has less friction, aiding smooth action. If you are not comfortable enough with hand saws to have your off hand in such proximity to the blade (one might easily argue that no amount of experience would recommend this) then the block of wood may be secured just to the other side of the cut line opposite the fence to act as a sure guide. In reasonably short-ish cuts, such as that proposed in the question, the drift off of square from the set of the teeth shouldn't be significant and with practice, can be easily compensated for with a bit of attention paid while cutting. If you do find your cuts are drifting off square enough to matter, a small relief chamfer off the bottom corner of the fence and clamped block to provide space for the set of the teeth, will allow the block to be pressed gently against the saw plate thereby mitigating alignment error throughout the cut.

Answer 2

The problem with using the mitre saw is that at acute angles you lose length of cut and jig set up can lack stability and safety. You need to clear your table saw. It is the safest most useful tool in your shop. Make a plywood sled that tracks in the T square slot opposite the fence. Glue a 3/4" wide X3/8 thick ply strip to one face of a decent piece of European birch ply 1/4 to 3/8 thick 30" X 24" parallel to the long edge. Such that when you run it by the saw the. First time. The saw trims the sled edge perfectly flush with the kerf of the cut. Make sure the tracking strip is just slightly loose so it won't bind in the slot. Wax the runner strip and the bottom of the sled. If you don't have an out feed table you will be limited to smaller cuts. I have built both in feed and out feed tables flush with the height of my table saw. I keep them smooth and waxed so every thing slides easily. When using the sled, over hanging ends of pieces to be cut can be supported by waxed shims you should keep on hand. Don't wax the top surface of the sled. Masking tape can be used to position stock though downward hand pressure usually suffices. Keep your saw sharp. Use reasonably dry stable stock to avoid a bind or if the wood has built in stress rough cut and then trim to your line. This is an extremely useful technique. The infeed and outfeed tables allow one man to safely cut much larger peices. Using the sled allows you to place a piece of stock at any angle to your saw's line of cut. The length of cut is limited by the length of travel of the sled. Your outfeed table if there is one will need to have carefully routed extensions of the T slot to extend the controlled slide of your sled. These slots should be waxed as well. To glue the sled strip to the sled platform put the strip in the slot with a thin shim full length that raises the strip just a hair proud of the saw table run a thin, 1/16" bead of glue along the strip and place the sled on top with about 1/8" overlapping the kerf of the saw and place some weight on it till the glue sets up.

Answer 3

your best bet is probably the band saw, since the table is at least a bit larger than the miter saw. You could do this on using the miter gauge (a 45º spacer block will work). Alternatively, and probably preferably since it's more of a rip cut, a tapering jig riding against the fence would do it. for example, see the easily made (on the bandsaw!) jig shown here: https://www.popularwoodworking.com/techniques/tapered_legs_on_a_planer

Answer 4

I think I may have a way to do it with your miter saw! clamp a piece of wood to one side of your fence, but not the other. This will turn your actual piece that you are trying to cut, before you even swing your miter saw over. Kind of hard to explain, but once you try this, it should be fairly easy to get the gist.

Answer 5

There's an awesome tutorial on how to set your mitre saw for weird angles: https://www.youtube.com/watch?v=PQsPwY-eoFI

This is about making perfect corners for baseboards, but she shows you how to measure so you can make your mitre saw work for odd degrees...