Intro: Table Saw (Circular Saw Mount)
Before I even give a list of materials for this (small) project, I want to give a few reasons and warnings.
I made this mount in a few hours of trial and error, because I had many, many repeatable angled cuts to make, and I'm lazy. With a Jig on a table-saw this is easy and quick, and you only have to measure once (by clamping a stop to the sled). I d̶o̶n̶'̶t̶ didn't have my own table-saw - but this one worked out pretty well.
I have posted this as an Instructable because of comments by multiple friends who use this site. I was skeptical of doing so because I'm sure other people have done similar in the past, and because of how dangerous this is. You don't need to tell me its dangerous to do this. Believe me, I know.
A table-saw (like any other power tool) is an inherently dangerous item. This jury rigged version is even more so. If you are not used to working with power tools, or if you have never used a table-saw before, I would not suggest this be your first experience. A saw of this nature is powerful enough to throw a work piece up at you, dislodge your hands, or drag you in via your clothing.
A commercially made saw will include certain safety features. Typically, a blade guard and a riving knife/splitter. These both limit kickback, and make it harder for you to put your hands somewhere really stupid. A commercially available saw is also much more accurately fitted, as vertical as can be, and perfectly in line with any attached fence. They also have an on off switch easily in reach, and some have a pedal/kick button for this purpose.
Without these safety features you need to be even more vigilant and take all of the precautions you should with any table saw. Be alert and careful, not distracted. Keep your hands well away from the blade. Do not stand directly in front of the blade (to stop smaller pieces being thrown at you) and never work out of shouting range of someone who can use a telephone.
Step 1: Tools and Materials
I made this mount (and the sleds) with what I had to hand. I'm sure you could do better...
To make this exact table mount for a circular saw, you will need;
- A Circular saw
- At least 3 small toggle clamps + fixings
- 3/4" Ply (mine is 14" square)
- A Router & straight bit (I used a 1/2" bit)
- A cable tie
- Some clamps
- An Engineers Square
- A pencil (or a box full if you are like me)
To make some sleds like mine, you will also need;
- some 2"x1" timber
- some batton
- a protractor (if you wish to make any angled sleds)
Step 2: Mark Out Your Mounting Board
First, use your saw to cut the ply down to size. My mount is 14", but this does limit what you can cut. For me, this is fine as I have plenty of space on my jury rigged workbench, and eventually, this will slot into a hole in a larger workbench. Your mileage may vary. Try to make sure the cuts are straight and at right angles... it really does make life easier later.
Once your board is to size, turn off your saw. Remove it from the mains. Seriously. It's a dangerous tool, and you're going to be handling it a lot.
Take the blade out of your saw, and offer your saw up to the board. Taking the blade out allows you to have the saw flat to the board, and the motor housing in its final position. This will give you a good idea how to center the saw so that there is adequate space to support the board on all four sides when the saw is in place. It will also allow you to offer the toggle clamps up, and make sure they will fit in the right places.
You may find your saw actually has pre-drilled holes in the footplate for exactly this kind of mounting. If so - that's great! You can use screws instead of the toggle clamps. But be aware that if you want to regularly attach/detach the saw, the more you use those screws, the weaker the grip will be to the board.
My saw is mounted in the center of the board - this puts the blade off center, and the motor off center the other way, giving me just enough clearance for the toggle clamp and a support on the motor side. Its a shame that the saw blade wasn't more central, but the board i had wasn't big enough to do so.
When you are happy with the location of the saw, take out your engineers square, and square up the saw. Then draw around the footplate of the saw.
Step 3: Make the Recess
I'm English. I tried to make sure i didn't say rebate for this title, because that's money back for you Americans. But I also realise I just told you to make a lunch break for your saw. Ho hum.
I decided to recess the saw into the surface, because my saw only plunges a couple of inches, so it would only protrude by 1.25". It also makes the mounting more repeatable if you will detach the saw for other purposes.
Using a fence (bit of metal) and some clamps, I made a couple of passes with my router along the inside of each edge of the marking we made. Never take out too much material at once with a router - you can burn and or split the wood. A quarter inch at a time is plenty. You could do this freehand, but a snug fit is fairly important here.
Once the edges are done, freehand the router to recess the rest of the hole, until you have something similar to the photo (but without the clamps and hole. I didn't take enough photos).
I Had to put another cut along where the blade fits, because my saw doesn't lift all the way clear of the footplate.
Test fit the saw. If it doesn't fit, carefully shave once edge at a time using a fence.
If you don't have a router, you could skip this step (but I wouldn't recommend it). Or use some chisels, or even use the circular saw at a shallow depth with lots of passes. But I have a router. :p
Step 4: Mounting the Saw
Drop your saw into the recess, and admire your snug fit and precision handiwork (or in my case, think "that'll do"). My saw requires a thump/the clamps to push it into the hole. The saw stays in the recess after disengaging the clamps, and requires a good tug to detach. On the plus side, I know it's in the same place every time I attach/detach it.
Now its time for the toggle clamps. I used three, because then it shouldn't wobble. Wobble is the enemy here, because it will make this thing EVEN MORE DANGEROUS. (I bet you thought I wouldn't mention the danger again).
When you arrange the clamps, put them wherever they fit. But please be careful if you plan on tilting your blade (as i have). Bad placement could mean that when you tilt the saw, the blade (or other parts) touch the clamp. Make sure the screws you are attaching your clamps with are not too thick for the board. My clamps will apparently hold 27kg each (I doubt that) so make sure your screws are thick enough to hold a similar weight. Otherwise, you could tear the clamps out when you engage them. Adjust them as appropriate to hold the saw in solidly.
All tight and solid? I clamped my board to my workmate (with the blade over the hole), but you could use trestles here, or the saws final mounting location. Refit the blade, plug the saw in, and use it to plunge down into the board. go slowly and gently, you will splinter the surface otherwise.
I also plunged mine through at 30 degrees, so I could make some specific cuts. Again, do this gently if you choose to do so. (I splintered the surface of mine badly here due to my impatience).
Your saw is ready for use! Well. Kinda. Make sure your saw is unplugged, cable tie the switch to on, and make
sure the mount is clamped down to something solid before you turn it on and test it (I know I had to).
If you stop here, be really careful and always line your fence up parallel to the blade. There is a good Instructable on that kind of thing here. Step four. But you don't have a miter gauge... or anywhere to mount one... yet.
Step 5: Cutting the Rails and Making a Sled
Before this step, I'll warn you again. My sleds are not very safe. A normal sled would have a bottom, which you rest your work piece on, not just a back piece. These sleds could be described as posh push sticks. And they need lining up carefully. The whole arrangement needs to be treated with care and respect, and the cutting table should be kept clear of dust and debris.
Turn off and detach your saw. You should have one slice in it, nice and square to the edges of the board. Mine wasn't quite square. If it is, you could use your square to mark the rails from the edge of the table mount. Is is important that these rails are square to the blade, as otherwise you will be pushing the stock at an angle to the blade, which will mean the stock will kick, and the blade could stick.
Get out your square, and draw lines perpendicular to the top and bottom of the blade hole (technical term there). Measure the same distance along both lines, and make a mark. Then connect these two marks. This will be the location of the rails, parallel to the blade.
Set up a fence, and run the router along it. You only need a depth of quarter inch or so here.
I wanted a sled to cut at a 30 degree angle. I grabbed a bit of 2x1 (actually a bit of pallet) and marked out some 30 degree angles (top and bottom) of the timber. A little maths and or a ruler would allow you to work out where to put the second line. This would probably have been more accurate, but I didn't do it this way.
I used the router to cut a channel on my markings. I then cut some batton the width of my router bit (1/2") to fit in those channels. Then I put the batton in the channels and made a cup of tea while the glue dried.
After my cup of tea, I offered up my sled to the table. I then used a pencil to mark the location of the second groove. Then I made sure it was 30 degrees, used the router again, and fitted some more batton.
Step 6: Enjoy!!!
Now that you have a table-saw (even if it is a jury rigged version), you can do all kinds of neat stuff. Well, you can make lots of repeatable cuts quickly.
All of the cuts for the images on this step were produced on the table-saw, using various sleds and jigs. This was significantly quicker than cutting them by hand with a miter saw, but putting the table-saw together probably took more time than I saved for this project.
Using a sled allows you to measure once for many cuts, as you can clamp a bit of scrap to the sled, giving you something to push material up to before cutting. Be careful with the clamps you use, and keep them well out of the way of the blade. Angled sleds can be dangerous because of this.
Good luck and happy sawing!