How To Make A Precision Miter Sled (Updated) Homemade Machines & Jigs
My miter saw station is my go-to tool for making accurate square and angled cuts on narrow stock. It can handle boards up to around 12″ wide at 90 degrees, and in a pinch it can go wider by flipping the stock over and cutting from the other side. The width capacity for angle cutting is much less, but I don’t often need to cut wide stock at an angle. The few times that I’ve needed to, I’ve done it the “hard way” with a handheld circular saw and a clamped on guide.
This new miter sled will make that task easier. And it also gives me the ability to make a wider variety of angles and compound angle cuts than my miter saw can. For those of you that either don’t have a miter saw or a miter saw that you can’t rely on, this sled will make your saw into a precision miter cutting tool.
Printing the plans and getting the materials together is the first step. Here are the metal parts for one sled:
My carriage bolts are all longer than needed, but I can cut them off to the correct lengths. For simplicity I usually only buy two lengths: shorter and longer, and then cut them as needed.
The base has a curved cut on the outside edge. The easiest way to layout this curve is to use a strip of hardwood and just bend it to line up with the end point:
The curve doesn’t have to be a specific radius. It’s just there to keep the fence shorter and allow it to clamp onto the base at sharper angles.
I cut the curve with my jigsaw and then smoothed it with a block plane and sanding block:
A word about the base: I’m using 1/2″ cabinet grade maple veneer plywood for mine and I selected that because it is very flat. Another option is MDF, but it’s quite a lot heavier and less durable. Baltic birch plywood will work as well, as long as it’s flat. Flat and staying flat is very important.
Here I’ve marked the location for the pivot and drew lines to help line up the scale later in the build:
And I drilled a 1/8″ hole at the intersection. This will be for the pivot pin in my circle cutting jig:
Next I can set the jig to start cutting out the pivot insert hole. The size of this doesn’t have to be a precise. The important thing is that the insert that’s made next fits in there perfectly:
The insert hole is stepped with the bigger opening on the bottom:
The Pivot Insert
I cut a rough blank for the pivot insert from the same plywood the base is made from. That’s important to get the same thickness and expansion / contraction rate:
It’s a VERY good idea to cut two inserts at the same time. That way if you make a mistake on the one you just did a cut on, you’ll still have the other to correct it.
I rigged up a crude circle cutting jig for my router table to make the cuts in the insert:
The pivot insert must be a very good fit in the opening. If there’s too much play, make it again. It has to be a snug fit for the sled to work properly:
I drilled the counterbore and hole for the carriage bolt next. The bolt fastens the pivot insert to the inner fence:
Note that the counterbore is drilled on the bottom of the insert.
The Scale (updated – see below)
Next you’ll need to download and print the scale. Clicking on the image below will open the full size version. Right click that and select “Save as…” and save it in a convenient place. Double check the size – it should be 2569 x 1985 pixels.
I’ve updated this project with a few minor changes, including this new scale. Scroll to the bottom of this page for more details. I haven’t revised the plans, since these changes are very minor and easy to follow.
To print, right click the image and select “Print”. On Windows you’ll get a screen like this:
Uncheck “Fit picture to frame” and make sure Full page photo is highlighted. If using some other print utility, make sure that scaling or fitting to page is turned off. The print is sized for standard 11″ x 8.5″ printer paper.
Mine looks a bit different – it’s the early version. I printed it on thicker stock, matte photo paper:
I made some cuts on the print to mark out where the recess needs to be cut for the scale to fit into:
Then set the depth of cut on my router to about 1/32″ and set the radius to 3-11/16″ (updated) for the inside of the recess:
I used a 5/16″ bit and made a series of cuts to produce a recess that is 1-1/2″ wide:
Checking to see how the scale fits after cutting out the centre:
I could then line it up accurately and tape it in place. I used a glue stick to adhere the scale, being careful not to move it. The point marked on the scale lines up with the centre of the hole in the pivot. The other lines drawn earlier on the base line up with the lines on the scale print.
The rest of the sheet is then trimmed off and discarded:
If done this way, the scale in relation to the pivot will be very accurate.
I also cut a 1/2″ wide rabbet along the outer edge and made a slot in the bottom of the base for the guide. Both of these operations are shown in the build video at the bottom of this article, and fully detailed in the plans.
The inner fence is made from two pieces of 1/2″ thick stock. I’m using oak for mine, but any clear wood or quality plywood will work as well. It needs a slot for the fence lock bolt and I’m cutting that before gluing the parts together:
Using my mini table saw sled to make a series of cuts to create the slot. It can also be done on the router table, but I think this is easier :
Clamping it together on my table top will hold the parts perfectly flat while the glue dries:
I cut the parts slightly oversized so that I could trim off any mismatch when they were glued together. And you really need to make sure that your saw is cutting at 90 degrees accurately and check that now with a reliable square:
This slot for the outer fence was cut on the router table with a 5/16″ bit. I did it in several passes from both sides:
I marked start and stop locations on the stock that line up with the fence wings on my router table, and show that in the build video below.
Next are the counterbores (bottom and top) and through hole for the carriage bolt that fastens the inner fence to the pivot insert:
And drilling the counterbores and holes in the outer fence and fence lock. I made the fence lock from two pieces of 1/4″ plywood and cut those with two different size hole saws:
This can also be made from 1/2″ plywood with the step cut into it.
After the glue dried I clamped it in my wooden drill press vise and drilled the counterbore on the bottom:
I used epoxy to glue the carriage bolts into the fence lock and outer fence. Polyurethane construction adhesive also works, but takes longer to set:
The Guide Bar
The guide bar for this sled is unusual in that it can be put in two locations. The standard is for the blade straight up for a 90 degree cut. The second moves the sled 1/2″ (the thickness of the base) away from the blade for bevel cuts down to 45 degrees.
It’s “L” shaped and fits snugly into the slot that is cut in the base:
The slot in the base is the distance from the left face of the blade to the edge of the miter slot on that side. This is for a table saw that tilts left. You can choose to have a fixed guide bar for a saw that tilts to the right, since it tilts away from the sled.
The majority of table saws made these days tilt to the left, so there’s a good chance you’ll be doing this.
I made mine so that a single small screw in the middle holds it in place. Rare earth magnets (they need to be strong) that are epoxied in is another method:
Gluing the fixed guide bar and lock bars to the bottom of the fixed base:
The fixed base can be any size you want, and I made mine just wide enough to cover the miter slot of the right side of the blade. It’s located close to the blade on a left tilting saw to minimize the gap.
The fixed guide bar stops the base from moving sideways, and the lock bars from moving forward and back:
On a right tilt, you may want to make it so that the guide bar is offset enough to move the base away from the blade when it tilts. This would be done by turning it around so that the other edge is beside the blade.
I made a few test cuts after the sled was assembled and adjusted:
I made a video to show how the fence is adjusted so that it is square to the blade:
It should look like this after it’s aligned:
The fine adjustment is just that – fine. The scale must be placed accurately for the sled to work well. You can always glue in a new one if the first one is wrong.
A couple of pictures of the finished sled:
The build article:
I’ve hung it on the wall with my two other favourite sleds to keep it conveniently within reach:
Soon after I finished the sled I realized that it really show go to at least 45 degrees the other way. So I made some changes to mine and redid the printable scale included here to allow for that added functionality.
Rather than replace the original on mine, I printed a full 180 degree scale that’s a bit smaller and added that:
Once again I coated the scale with water based poly to seal it:
And made sure it lined up perfectly with the original.
I also rounded the back end of the sled:
And extended the rabbet underneath to wrap around the corner:
After I had the fence lined up again, I locked it in position by drilling and driving a screw through the pivot and into the inner fence: