Tips and Jigs Part 1: Circular Saw Straight-Cutting jig

For many of us, the cost of a table saw is too much just to be able to make long straight cuts in sheet lumber. If you buy a smaller table saw, you are actually creating a very dangerous situation as these are not meant to cut large pieces of lumber. What about space. A table saw is a space hog, especially when not in use.

SOLUTION? BUILD A JIG! A circular saw is a very common tool for home owners. You can buy battery powered versions that come in kits or go for a nice corded one. This should take you about an hour if you have all the supplies.

This instructable is a follow-on to a concept presented by http://www.instructables.com/id/Cutting-plywood-the-easy-way/

Step 1 Getting Started: Supplies and Information

Items you need:
Circular saw (1)
Hand Drill (1)
Countersink (1)
#10 Drill Bit (1)
Countersunk 10-24 sheet metal screws (15)
10-24 nuts (15)
lockwashers (15)
Sheetrock screws
4x8 1/4" Hardboard
1"x1"x1/8" Aluminum Angle (Length as desired)

Comments

[gephardt]

Hmmm. I have always felt safer with a table saw, and mine cost no more than most decent circular saws. Does take up some space, but it suits my needs better.

[sabr686]

I don't get it

[Pkranger88]

What do you not get? All the wood paneling on the workbench is plywood. In order to cut a straight line, I used the jig to get those straight lines. This was merely a "here's a result of the work" pic. Does that answer your question?

[sabr686]

Okay, thanks mate.

[evertonp]

Hello,

I really enjoied your instructable. Congratulations.

Regards,
Everton

[bobtannica]

Really liked your instructable. I would be very interested in seeing a table saw base as you suggested. Keep up the good work.

[garethfarfan]

Wow, this is a lot of work for nothing. Something wrong with just clamping your angle to your piece of wood being cut and running your saw's existing edge against that?

[Pkranger88]

Saw blade's have a nasty habit of twisting the saw away from the direction of cut. Slight corrections are required that result in a slightly jagged edge. When using a "free" guide, you must create constant pressure on the jig or the saw will drift away. Keeping constant pressure on long cuts is fatiguing and leads to twisting the saw counterclockwise. This jig prevents all this. By creating a "rail" for the guide's groove to follow, there is no correction necessary. You can create higher quality cuts both in accuracy and cleanliness by using jigs like this. This jig is specifically designed to take the frustration out of longer cuts in plywood. Shorter cuts would not necessarily benefit from this jig. The concept is similar to the crosscut jigs used in lumber warehouses to crosscut sheet lumber. A lot of work for nothing? NO. On the contrary, excellent cuts for 2 hours of your time. I just finished building a solid oak framed workbench and all the sheet lumber was cut with this jig. And the cuts were beautiful. No one would have been able to create such square and straight cuts using just a straicht edge. I guarantee it.

[boognishmofo]

This is a great instructable. I thought at first you were going a completely different way with it. Since you have a pretty darn sturdy base on it could you not turn it upside down mount it in a table and put a switch to make a table saw? I have an old wet tile saw that I was thinkin bout turning into a table saw but I have way more old circular saws lying around. Any info would be greatly appreciated.

[Pkranger88]

I've thought about making a "tablesaw" base for a circular saw and mounting a switch. I don't see any problems with it other than the difficulty with fine-tuning height and angle adjustments. I may just do one and see how it works out.

[jdege]

What are you doing to ensure that the aluminum angle is straight, when you screw it to the hardboard? The stuff does flex, and any error that's present in it will be replicated in your cuts. Even if it is straight at the time you screw it to the hardboard, screws won't keep it straight. Over time, play will develop in the screw joints, and the angle will move out of true.

[Pkranger88]

A little glue between the surfaces won't hurt either.

[Pkranger88]

I clamped a level to the aluminum angle when I mate-drilled the holes to the hardboard. After over 50 cuts, it hasn't bowed yet. Keep in mind that the lateral force it has to maintain is quite small in comparison.

[jdege]

"I clamped a level to the aluminum angle when I mate-drilled the holes to the hardboard." You should add that to the instructions. It's a critical step.

[Pkranger88]

Done. Now go build one. I wouldn't say it's a critical step though. Deflection is going to depend on binding the angle when you clamp it. A sharp drill bit and a steady hand will work fine. The first time I made one of these, I clamped and drilled and it was as true as any woodworker could ask for. Thanks for the interest though. I'm working on getting a few more of these up here. Check back often