My Table Saw From a Circular Saw Redone

More than 40 years ago I wanted a table saw, but had very little money. I bought a good circular saw and hung it below a piece of 3/4 inch plywood. I added a couple of my own innovations, and it could do very precise work. I could also remove the circular saw to rip a panel too large for my table saw, and put it back into my table saw without the need to align it again. I no longer have that circular saw or the table I made. See how I made that table saw here.

But, I wanted to have a table saw again and wanted to utilize my Porter-Cable circular saw (Model # PC15TCSMK). This saw has a rigid base that does not flex easily, a 13 amp motor, and almost no run out to change the line of cut when the motor starts.

What I do not have is a lot of space to store a table saw, so I wanted a saw that almost stores flat. See the second photo. When I want to use the saw, I back my car out of our garage and set up my saw near the open door on folding sawhorses.

Materials

3/4 inch plywood 29 x 48 inches for the saw table
3/4 inch plywood for the fence and the face of the miter gauge
Steel bar 1/4 x 2 inches and 1/4 x 3/4 x 24
1/4 inch and 5/16 inch threaded rod
8-32 machine screws about 1 1/2 inches in length
Various nuts and washers
3/4 inch water pipe
Angle iron from an old bed frame
Steel fence post
Steel electrical boxes and covers for a switch and an outlet
Three 3/8 inch romex connectors
15 amp duplex outlet and 15 amp toggle switch
Twist on wire nut
Three prong male plug
16-3 rubber covered wire
Round steel bar to make the collar in step 2
Concrete reinforcement bar for the carrying handle
1/4 inch plywood

Tools

Circular saw
Radial arm saw
Dado blade (adjustable)
Framing square
Folding rule
Router
Handheld Drill
Drill press
Welder
Angle head grinder with a cutting wheel and a grinding wheel
3 pound hammer
"C" clamps
Plywood straightedge guides
Pliers
Screwdrivers
Files

First Step: Cut the Miter Gauge Slots

The miter gauge slots need to fit the miter gauge's steel bar precisely. I used an adjustable dado blade with carbide tips to dial in the exact width of the 1/4 x 3/4 inch steel bar I planned to use for the miter gauge. I made test cuts in some scrap lumber. In the process I learned two bars may be classed as 1/4 x 3/4 inch, but one is a bit narrower than the other. I cut my slots to fit the piece of steel I would use.

I also have a radial arm saw now. One capability of a radial arm saw is using the edge of the table nearest the operator as a cutting guide together with a straightedge clamped to the bottom of the work piece. I described that process in this Instructable. I have a piece of 3/4 inch chipboard about 4 inches wide and 36 inches long. It has very straight parallel edges on both sides. I clamped it under the piece of plywood you see in the photo. It was positioned midway between the two slots in the table and was parallel to them. All I had to do was set the depth of the dadoes and hold the plywood firmly on the table while cutting one slot and then turning the plywood end for end to cut the second slot. The process is almost failure proof and the finished product is very accurate.

The Miter Gauge

The bar stock for the miter gauge is ( as mentioned earlier) 1/4 x 3/4 mild steel about 23 inches long. I also had a piece of flat steel 1/8 inch thick and about 8 x 10 inches. The miter gauge has a wooden face about 2 inches high. The miter gauge is wider on one side than the other because of where I had to place the slots in relation to the steel plate that mounts the saw. The miter gauge can swing to a little more than 45 degrees left or right.

See the second photo for how the arc opening was cut into the 1/8 inch steel. I am illustrating with a piece of 1/8 inch Masonite. Drill a 1/4 inch hole for the pivot point. Bolt the steel to a 2 x 4 so the steel can pivot left or right. Clamp the 2 x 4 to the table of a drill press. Drill a series of holes next to one another as the steel pivots through its arc. After the row of holes had been drilled, I used the edge of a grinding wheel on a 4 inch angle head grinder from both sides to remove most of the metal between the holes. Then I used a file to smooth and fit the arc slot so the steel can pivot smoothly with the lock down bolt in place.

The pivot bolt and the lock down bolt are both 1/4 inch. The steel bar can be drilled and tapped, or bevel head screws could be used. I drilled the holes and welded threaded studs in the holes.

See the third photo. The pivot hole did not fit tightly enough around the pivot bolt. There was some wiggle. So, I made a collar with an outer diameter of 1/2 inch. I drilled a hole in the 1/8 inch steel almost 1/2 inch in diameter and filed it by hand for a close fit on the collar. I welded the collar to the pivot bolt. I used washers to fit over the small welds and a self-locking nut to secure the 1/8 inch steel on the pivot bolt.

The fourth photo shows how the wood is attached to the steel on the miter gauge. Although the bevel head screws were countersunk, some grinding was still needed to make the bottom surface smooth.

See the fifth photo. It is a handle for the miter gauge very similar to the handle on the miter gauge I bought from Sears for my first saw conversion 40 years ago. It was a very useful feature. Already I was finding the wing nut shown in the first photo for this step tedious and difficult. I cut two slots into the end of a piece of 3/4 inch water pipe. I filed them until the wings on the wing nut could slide into them. I positioned the piece of water pipe over the wing nut and tack welded it in place. See the sixth photo. I finished the welds and used a cutting wheel to make grooves on the side of the water pipe for a nice grip, especially when loosening the miter gauge to adjust it.

The Saw Mounting Plate

40 years ago I simply used two 1/4 inch bolts with bevel heads and wing nuts to hang my saw under 3/4 inch of plywood. That meant the maximum cutting depth was reduced considerably. Thicker pieces of work required making multiple passes: one normal pass, inverting the work, and making a second pass. This was not a big problem because most of my sawing involved 3/4 inch stock.

This time I wanted to keep as much of the saw's cutting depth as possible. I had some pieces of steel 1/4 inch thick and 2 inches wide. My first plan was to make a frame for the saw's base and support the saw on some welded tabs from below so the base of the saw would be flush with the surface of the steel frame. It worked, but I decided the saw was not secure enough and might move while in use, so I removed the tabs and welded more pieces of steel into the frame. I hung the saw from threaded studs welded into the steel mounting plate, one of which will be seen in a later step.

Someone will surely wonder about the rather large throat plate clearances. They are necessary so the saw can be used when the blade is laid over for bevel cuts. A solution to the large throat clearance will be shown in a later step for when a very close throat clearance is needed for thin pieces.

Welding extra pieces into the initial frame caused warping. After welding I did some work with a 3 pound hammer. I also did some grinding. A one piece steel plate would have made this easier and eliminated the need for some of this corrective work, but I wanted to use what I had.

The plywood is recessed by means of a router so the surface of the plywood and of the steel mounting plate are even.

See the second photo.I found the level of the steel mounting plate was just a little below that of the wood saw table. For many things this created no problem. But, it was potentially problematic when sawing smaller pieces where precision is important. I brought the level of the mounting plate up to that of the rest of the saw table where necessary by smearing a liberal application of auto body putty (Bondo) on the steel plate. I used a piece of 3/4 inch wood on its edge as a screed to level the body putty much like a mason would do to level freshly poured concrete in a form. As a last step I wrapped some medium sandpaper around the bottom of the piece of wood to further smooth the auto body putty.

The Underside of the Mounting Plate

The first photo shows one of the 5/16 inch studs for mounting the saw. The criss cross bracing pattern cast into the saw base leaves no place for a nut. I added a square steel washer I made so the nut can work as it should. A second mounting stud is at the hole in the other end of the saw base. In the lower left corner of the photo you can see the stud and nut that secures the steel mounting plate in the plywood. The mounting plate fits very tightly in the plywood, especially on one particular side.

See the second photo. Notice two wooden blocks attached with studs and nuts. A machine screw runs through each so their tips touch the saw base. Either screw can be turned part of a turn to move one end of the saw's base over just a few thousandths of an inch. (Space for reaching the screw heads is limited. I use a needle nose locking pliers to make adjustments.) I used this system in my saw from 40 years ago. Once aligned, the saw can be removed and put back in place later. Simply slide the saw so the base touches these two screws and the saw is precisely aligned again. Then tighten the nuts on the mounting studs.

Underside Framework

The tan pieces of steel running up and down under the plywood are angle iron from an old bed frame. The green pieces connecting them are pieces of steel fence posts.

Notice the electrical boxes. See the second photo. One contains a common outlet receptacle. The other contains a toggle switch placed so it is easy to find and shut off in case of a problem during use of the saw. Both are welded to a piece of bed frame welded to the green fence post.

I also added a carrying handle that also helps control the cords while carrying. See the third photo.

Preparing to Use the Saw

Some alignment and calibration is necessary before the first use of the saw.

I have raised the long leg of the framing square a little so the other leg can catch in the miter gauge slot. I loosened the locking wing nut on the miter gauge and allowed the miter gauge to pivot until its face rests against the leg of the square. Then I tightened the locking nut.

See the second photo. If you wish to check your square for accuracy, you can invert it and see if the leg touches the miter gauge slot as fully as it does in the first photo.

This is all that is necessary to set the miter gauge for a square cross cut. Repeat the first part of this step anytime the miter gauge has been reset or disturbed. The third photo shows a cross cut checked with a square immediately after making the cut. (I have checked the square, too, and it is accurate.)

Align the Blade

During initial set up and occasionally later gently slide one leg of the square against the blade without putting pressure against the blade. If the leg of the square is parallel to the miter gauge slots, it should also be parallel to the saw blade. Use the adjustments in step 4 to align the blade.

Both the saw and the miter gauge should be aligned quite precisely now.

Rip Cuts

I am still making rip cuts the same way I did 40 years ago. It is not fast, but it works very well.

Bring the square against the miter gauge. Slide it for the correct width of the rip cut. Hold the square firmly to the table with downward pressure. Slide the fence against the square. (I use the factory edge of a piece of plywood. I have made a new higher fence from two pieces of plywood and it will be seen in a later step. Hold the plywood fence down at the front of the table and carefully clamp it with a "C" clamp. Do the same at the rear of the table. Check again to be sure the square touches the fence evenly along its length with no gaps. Remove the miter gauge and the square. If all was done well, there is no need to measure between the blade and the fence at the front and back of the blade, but it is a good check to perform, anyway. Make a small test cut. Adjust the fence, if necessary. In this Instructable I developed a reliable way to adjust the rip fence just a tiny fraction of an inch.

Zero Clearance Throat When Needed

When a close clearance is needed on the throat, a thin piece of plywood or Masonite can be brought near to the blade and the fence can be clamped with it in a sandwich.

In the photo I am ripping a piece about 5/16 x 3/4 inch down to 1/4 x 3/4 inch. I am using my new "L" fence that supports vertical work pieces better than my old flat piece of plywood.

You can also see the piece of 1/4 inch plywood that nearly touches the blade and supports the thin work piece very well. That piece of 1/4 inch plywood is a couple of feet wide and runs from the front to the back of the table. If need be, I could add a thin piece that covers the whole saw table with only a thin slot where the blade comes up through the table.

As a general safety practice, I like to keep the blade as low as possible. If my hand would happen to go over the top of the spinning blade, I would have only a flesh wound. I would not lose a finger or a thumb. (I read that advice many years ago in a DIY magazine article.) I need to make a featherboard yet for cuts like this.

Miters

I walked around to the the rear of the saw and placed the framing square so the corner is located over the miter gauge slot. I placed the square so the markings for 15 inches on both legs of the square intersect the back edge of the table. See the second photo. I adjusted the miter gauge so its face evenly touches one leg of the square. See the first photo again.

See the third photo. The miter gauge did not catch any of the square, so I used a straightedge ruler as an extender.

Later I made a miter sled from old bed frame steel and a 1/4" x 3/4" bar to fit the miter slot. (fourth photo) The steel was not straight or uniform enough for precise work, so I added a facing of 1 x 2 pine held in place with multiple screws. Then I used my regular adjustable miter gauge to trim and square the pine facing so the edges are straight and true. The bed frame is attached to the bar with screws and there is room for adjustment. I took time to adjust the miter sled so I can cut two pieces from the same side of the sled and they still form a 90 degree corner.

What Will It Do?

After a few months I have mostly used this saw to resize lumber for very mundane projects. Shown are photos of two projects I did with this saw. The first photo is a slipcase for a used Hebrew/German Old Testament my brother gave to me. The slipcase prevents the binding from becoming looser during storage. I used clear pine and fiberboard to make this slipcase.

This was photographed with my iPhone 4S camera from a very close position, so there is an unnatural perspective. And, I used a router table for forming some of the cut profile. But, miters and other cuts were made on this table saw. I made a couple of trial cuts and adjustments on the miters before they fit as I wanted.

The second photo is of a processional cross I am making for our church. All of the miters were cut on this saw with the miter sled shown in step 10. The wood is 1/2" red oak joined with biscuits.

I have continued to tweak my table saw for more ease of use and insured accuracy. But, it works very well already and is a nice tool to have when my other tools are set up for special needs I do not want to disturb yet. Most of this saw adaptation was built with discarded materials. Since making this saw adaptation I made a sled for putting a true edge on a board that has become wavy, but without making holes in the good board that mean sawing around the holes. Click on the link in the previous sentence.