|Project by thetinman||posted 04-30-2014 05:53 PM||3518 views||20 times favorited||6 comments|
EDIT: THIS PROJECT WAS EDITED ONLY TO ADD A LINK TO THE DRESSED OUT TABLESAW
This project is part of a bundle of projects building some basic shop tools and table saw jigs. The project series concludes with dressing out the table saw. As each project is posted links are added to the items in the list to keep everything bundled.
ZC Plug for Factory Plate http://lumberjocks.com/projects/99601
T-Square – Circle Saw – Router Guide http://lumberjocks.com/projects/100650
Dowel Cutting Jig http://lumberjocks.com/projects/100728
Tablesaw Push Sticks http://lumberjocks.com/projects/100725
Pimped out Table saw: Router Table, Router Fence, Left Side Table, Out feed Table, Shelves/Cabinets
This T-square is my go-to whenever I build anything wider or longer than 12-inches. It is an indispensable tool when working with sheet stock, building tables, bookcases, cabinets, etc. It’s always a good thing to have a lightweight easy to manage square for larger projects. We all have to manage cutting down sheet stock into the sizes needed. This T-square provides a cutting guide for your circle saw insuring an accurate straight cut that always yields a square edge. It is also dandy as a router guide.
Begin by getting the 3 measurements needed to build the T-square. First measure the height of the motor above the board being cut. Mine is just over ½-inches. This is the maximum thickness you can use for the T-square blade without having to raise the motor.
Second measure the distance from the inside edge (the edge to ride along the guide) to the end of the motor. Round this measurement up to the next full inch. Mine is about 3 ½-inches rounded up to 4-inches. Third measure the distance from the same inside edge of the base plate to the saw blade and add about ½-inches to this. Mine is about 4 1/2-inches so I used 5-inches.
Make the Blade
Now figure out the dimensions for the blade (body) of the T-square. Decide on the length of the blade you want. I like a 26-inch usable blade. It’s short enough to be light and manageable while being long enough for standard cabinetry. It also gives a long enough run to line up a longer cutting guide if I’m going across a sheet of ply. Add whatever usable length you decide to the width of the T-square head. I have a 26-inch blade and added 3-inches for the head stock width giving a total length of 29-inches.
For the width of the blade, add the distance from the base plate to the motor (4-inches for mine) plus 2-inches. Mine yielded a width of 6-inches. The extra 2-inches of width gives a clamping surface when cutting without interfering with the motor.
So my T-square blade is 6 X 29 and a maximum thickness of just over ½-inches. Now select what material you will use for the blade. (What scrap is laying around?) I found a piece of 1/4-inch marine plywood interior boat decking.
Make the blade. With a good blade in your tablesaw, begin by just trimming an edge along the plywood. This leaves a nice edge to start with. I never use a factory edge or an edge on old scrap that’s been laying around. Now flip the board around and rip it to the width. Using the miter gauge, just trim an edge square then flip it and cut to length.
Make the Head
Add up the measurements for the head of the T-square. You’ve already used some measurements to get the width of the blade.
The length of the head is the distance from the edge of the base to the blade (5-inches for mine) + the t-square blade/body width (6-inches for mine) + 6-inches. For mine it comes out to a length of 17-inches. I have found that a width of 3-inches for the headstock works well. So the head will be 3 X 17. The thickness is arbitrary. I prefer something at least ½-inches thick. Now find a piece of the finest material you have (OK, so it’s scrap). I found a piece of ½-inch old oak flooring I yanked out of an old school house. Make the head using the same process used for the blade.
Drill 6 Holes in the Blade
Drill a ½-inch hanger hole 1 ½ inches from one end of the blade and centered. Use a backing block of scrap wood so you don’t get tear-out on the backside. I step-drill large holes like this. I have found that a ½-inch bit it difficult to center and tends to tear out a lot of material. I start with a ¼ then a 3/8 then the ½-inch bit. It makes a cleaner hole.
Find 5 screws that you will use to attach the blade to the head. Cabinet hinge screws worked well for mine. Measure down 3-inches, or whatever width of the head you made, and draw a line across the blade. Draw an X from corner to corner. Using a backing board, drill pilot holes for the screws you selected and countersink the holes for the screw heads. One in the center and 4 placed 1-inch in on the diagonal lines.
Pre-drill Holes in the Head
Pick a side of the head to be the left side. (Assuming you are right handed and using a right handed saw. If you’re a lefty just think backwards) Measure in 6-inches and draw a line across the head. Hold the head along the side of the workbench and place the blade on top of it. Use a known good square and square up the t-square blade along the line on the head. Clamp the two pieces together. Double check that everything is square. Now drill 5 pilot holes for the screws in the head. You don’t need a backer board since the screws/holes will not go through. Get in the habit of drilling pilot holes. Without them the screw will pull wood up as it goes in. The wood pulled on top of the wood will not let the pieces come together. Check that everything is square again. Sometimes things move even when clamped. If you need to move a pilot hole – now is the time to find out.
Sand the blade and the head ready for assembly. Put some glue on the inside of the blade where it will mate with the head. Brush the glue out to a thin coating. Don’t just swirl it on out of the bottle.
Place the head along the side of the bench again and place the glued up blade on top along the line. Use your known good square to set it up and then clamp it. Put in the screws starting with the center screw. Keep checking that everything is staying square.
Wipe off any glue squeeze-out with a damp paper towel, rag, etc. Don’t use a wet towel. It just makes everything a mess and the thinned glue will run into the grain of the wood and make finishing difficult. Damp is all you want when cleaning glue off.
Also, clean the glue off the known good square you used for alignment. If you keep it waxed the glue wipes right off. If it does dry on your square the wax just lets it pop off.
Make the Guide Cut in the Head
I prefer to let glue set up at least a couple of hours (more is better). You can probably get away with continuing immediately since it is screwed together but why not wait? Have a beer – or two – or three.
Find a piece of scrap board and put it on the workbench. Put your T-square on the board and cut across the head with your circle saw running along the blade as a cutting guide. Now this end of the head is cut off to be exactly where your circle saw will cut. Make another mark on the piece of scrap board.
Move your T-square over so that the edge of the head you just cut off is right at the mark. Run your circle saw along the T-square blade as a guide and see that your cut is right on the line.
The T-square assembly is finished. You can add a finish if you wish. I just waxed mine with Johnson’s floor wax. The black marks you see on the oak in some of the pics are from the aluminum base plate on my circle saw. I used it to cut some concrete (yup a Harry Homeowner kinda guy). I sanded the scratches down etc. But I forgot to wax the plate. The marks would not be there if I hadn’t forgotten to wax.
OK, I said it was finished and it is. You can stop here. I realized that not everyone will have longer clamps so I cut down the left side of the head so it could be used with “everybody’s” quick clamps. You can make just square cuts or curved ones. Its up to you. You may not even do this step.
USING THE T-SQUARE
The T-square can also be used as a router guide in the same way. Trim rough edges like a mini planner or cut rabbits, dadoes, coves, etc. Depending on the thickness you choose for your headstock you may be able to cut a dado across it with your router and still use it as a cutting guide. A nice combo tool when making shelves or cabinets.
One small mark is all you need to make a precise cut that is straight and square. Just place the end of the headstock at the cut line, clamp down the T-square and cut. Frankly, for short cuts I’ve gotten used to it and don’t bother to clamp. If you don’t have a good blade (or even want to spend the money for one) in your circle saw – cut a bit proud. Make the final cuts on the tablesaw now that the stock is trimmed down to manageable size.
For longer cuts, measure and mark where you want to cut. Place the T-square just as though you are going to cut and draw another line on the board along the blade of the T-square.
Find a longer board to use as the cutting guide. Just make sure both sides are parallel. Now put your T-square against the board and slide it up to the line you drew alone the edge of the T-square. Clamp the board and you’re ready to cut.
When making long cuts, stop cutting about 16-inches in. Place a clamp across the cut at the end of the board.
This will keep the kerf from closing and pinching the blade causing the saw to buck. It will keep the cut piece from hanging down and catching the blade, again causing it to buck. And especially if you don’t have a helper, it supports one end of the board. This lets you finish the cut without that tear-off splintering we all know at the end. It lets you put your saw down while controlling the board you cut without the board falling on your toes. Remove the clamp and you have a good cut piece of lumber without a bunch of strain and comical acrobatics in front of the neighbors. Those moves are unnecessary – unless I’m the neighbor watching.
-- Life is what happens to you while you are planning better things -Mark Twain