Introduction: Circular Saw Cutting Guides

A decent hand-held circular saw can give a good, clean cut, but setting up to cut several pieces the same is very slow.

Measure, setup, measure again, check, measure again, check, pray is my usual process.

These guides are a pair of adjustable offset guides to allow me to set up a desired size of piece to cut from a sheet of ply and then very quickly repeat the cut to produce several pieces exactly the same size.

I did this using a quick and dirty fixed-size piece when I made some shelves and was so amazed at how much faster the cutting was that I decided to make these adjustable guides.

Step 1: Cut the Wood to Length

I had a spare strip of 18mm (3/4") ply about 80mm by a metre (3" by a yard) so that would be long enough to act as a jig for pieces up about half that width, while not being too awkward to keep in the workshop.

Cut the long piece in half, and then get a couple of chunks of similar (no need to be identical here) thickness and make the moveable end-stops.

Once the cuts had been made, I used an 80 grit paper to get rid of splinters.

Step 2: Cut the Slot

The key for the jigs is the slot for adjusting the end-stop.

I was going to use some M6 bolts, so the slot had to be at least that wide.

I was going to cut the slot out with a jigsaw, so the size of the jigsaw blade meant that drilling a 10mm (3/8") hole would allow ingress.

The holes were drilled equidistant from the end and sides and then pencil lines were marked between them.

Once a suitable way of holding the piece was worked out, the cuts were made, and then cleaned up with some sandpaper.

Step 3: Add Hard Contact Surfaces

Since the edge of plywood is quite soft and susceptible to knocks, I added a layer of hardwood to the surfaces which would be taking contact with the workpiece and saw guide.

This is the same deal as most of my other projects which involve wood whose appearance matters. Cut pieces oversize and hold them in place with masking tape. Then use lots of clamps and leave the glue to cure.

Step 4: Clean Up

Once the glue had cured, I planed the laminate down to the thickness of the plywood and then cut the horns off with a razor saw.

Surface markings from the clamps were taken off with sandpaper, and a pencil eraser cleaned all the remaining markings from the timber, and also did a fairly good job of cleaning off the dirt which had accumulated on the ply while it lay in the scrap box.

Step 5: Mounting Holes

Offer up the moving end-stop, mark through the slot and drill a hole. This doesn't really deserve a full step, but it didn't seem to fit logically in any of the other sections.

Step 6: Stain and Varnish

Cabot's Stain and Varnish (other such products are available). Needs a lot of stirring, but gives a good finish without too much skill or effort.

I made a rack from some wire which held the pieces hanging in mid-air which mean that I could cover all surfaces at the one time.

A delicate sand between coats and then the wood was ready.

Step 7: Assemble

These jigs should be adjustable, but solid, so I used wing-nuts to allow for one-handed tool-free tightening, while also providing a pretty strong grip.

A wider selection of washers would give a neater result, but the big fender washers were chosen to spread the load across the cut channel, while the smaller washers underneath were adequate for the non-moving location.

Step 8: Calibrate

To help with future cuts, I set both guides up at 50mm and made two little nicks in a piece of scrap with the circular saw.

Then I printed out some labels to give the offsets for inside and outside cuts using the aluminium (aluminum) saw guide which I use. Since I sometimes use metric and sometimes imperial, I printed labels with both measurements.

The key to this gadget is not accuracy, but repeatability: a piece of furniture which is 0.5mm (1/64") bigger than planned is much less annoying than one which has a 0.5mm (1/64") gap in a joint.

Step 9: Use

To use the guides, decide what size of wood is needed, and then subtract the relevant distance (demoed in previous section).

Set up one guide carefully (which takes time to check and re-measure).

Offer the other guide up and slide the end-piece to mate which duplicates the measurement precisely.

Make sure the wing-nuts are tight, then clamp to the workpiece and use the guides to position the saw guide.

I could not believe how much quicker cutting multiple pieces became once I had physical contact to confirm positioning, and I hope that you find this makes your cutting quicker too.

Comments

author
Kevanf1 (author)2017-08-01

Simple but brilliant, well done and thank you.

author
Alex in NZ (author)Kevanf12017-08-02

Thank you :-)

author
RayP42 (author)2017-08-01

So simple but such a great idea. I can't count how much time I've spent measuring one end of the saw guide then the other, then back again to make sure nothing has moved. This will get used a lot in my shop.
Well played sir

author
Alex in NZ (author)RayP422017-08-02

Thank you very much :-)

Good luck and do post your work.

author
david.haynes.1571 (author)2017-08-01

This is a good gauge for setting up the fence on a hand held "Skilsaw". I had looked at it for a table saw (circular as well) thinking this is an odd setup...but let's see...

I like the result, but it may need a new title as I mistook it to be the wrong thing. It is a good instructable, and I will make a set of these blocks, and use them for this, as well as lumber lay out and a few more ideas. Thank you.

author

Thank you for your kind words.

I usually try to avoid using trademarked names. Life is too short to argue with an IP lawyer :-)

Glad you worked out what I meant, and good luck with making and using them :-)

author

The title is accurate. A "Skilsaw" is a name brand for a circular saw. A table saw is a table saw.

author
tsmith47 (author)2017-08-02

Hi, I'm not sure i understand what the purpose of the guides is or how they are used. A video of them in use might be very helpful, or even just a sequence of photos showing the saw in process of cutting using the guides.

author
relbatto (author)2017-08-01

My apologies , i am on my first cup of coffee this morning, i see what you did and how you did it, thats clear , for some reson i am not getting how it is used with the guide, althought the ability to make angled cuts looks briliant.. any chance you can show it in use?

author
Alex in NZ (author)relbatto2017-08-01

I had never thought of using to set up angled cuts! Thanks for that.

Re. using it, the fourth photograph of step 9 was set up to demonstrate it in use.

Basically:-
1) Decide on width of piece you want to cut and subtract the distance figure (which you set up earlier in the "Calibrate" phase)
2) Set that distance up on one jig
3) Place the other jig against the first one to duplicate the distance
4) Use clamps to hold both jigs onto the workpiece
5) Alight the straightedge against the two jigs
6) Run the saw along the straightedge.

Good luck, and get back to me if I've not clarified :-) (And thanks again for the angle idea)

author
Trotamundos (author)2017-08-01

Nice!

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