Site icon Concord Carpenter

Cutting Acute Angles

Acute Angle Jig – Accessory fence

There are many times that I find I need cut trim or molding at an angle greater than my miter saw was designed for.  Most miter saws cut to 45 degrees or slightly larger, usually 50 degrees.


But what if you need to cut 55 degrees or a greater angle?  Cutting Acute Angles means a greater angle and one that miter saws can not give you without assistance.

One very dangerous way is to hold the piece to be cut perpendicular to the saws fence and freehand this cut. I do not recommend cutting trim this way. A safer solution is to make an acute angle cutting jig and keep it with your saw.

Acute Angle Accessory Fence

On a recent project I needed to install trim on  trapezoid style windows and built-ins. This meant that the trim angles were going to be larger than my miter saw was able to cut.

I constructed an acute angle jig, accessory fence form my Dewalt miter saw. This fence consisted of a 1/2 Birch plywood bottom and 3/4″ triangular sides. Two meet at 90-degrees and the third side connect s the two at 45-degrees. the 3/4″ parts and glued and nailed to the 1/2 plywood base.

The jig clamps to the miter saw fence, in line with the saw blade set at 90-degrees. I also used the saw hold-down, for extra support. Additionally I use a third clamp to hold the molding to the jig fence.


The result is a piece of base cap cut to 67.5 degrees.

Cutting Acute Angles with A Jig – 90 Degree Fence Version

I made this older acute angle jig,  out of scrap wood.

I arbitrarily chose 12″ x 12″ for this jig. I cut a 12″ x 12″ piece of 3/4″ plywood and then cut it diagonally to make a brace for this jig.

Scrap 5/4 trim makes up the edges. I chose 5/4 sides because the raised edges give me plenty of space to clamp or screw this jig to my miter saw table.

I clamped and screwed the parts together at 90 degrees.

The goal here is to make an auxiliary fence jig that can be clamped or screwed to my miter saw fence. Below checking for square. [90degrees]

A bar and spring clamp hold the jig to my miter saw fence for a trial fit.

Trying out just spring clamps… quicker but not as strong as a bar clamp. I’m getting thirsty looking at that ice coffee in the background!!

Once the jig is secure the trim is held tight to the jig and the saw can be adjusted to much greater angles than if you used the saws fence.

Test cut at 55 degrees.

Here’s another version of the fence I recently made

~ Concord Carpenter

If you enjoyed this post, please consider commenting or subscribing to receive my future posts via email

If you enjoyed this post, make sure you subscribe to my RSS feed!
Exit mobile version