Making A Wooden Table Saw – Part 2 Homemade Machines & Jigs
Continued from Part 1…
When I changed the lift slot from straight to curved, I went too far, so I fixed that with two more filler pieces:
Not that it was that important, but it does add some extra strength in that area. Again, one of the downsides of designing as you go.
To keep the threaded rod lead screw from eroding the bronze bushing it rides in, I over-filled the threads with epoxy and then filled it smooth:
I did the same on the end of the rod that rotates in the block at the back of the lift mechanism:
With the lift disassembled, I gave all of the parts two coats of water based poly to help seal it from moisture. The poly also makes the action smoother and acts as an anti-wear layer on the moving parts.
Another changes was to shorten the trunnion frames on the left side of the saw. This allows me to put a support bar for the top of the saw close to that side of the lift / tilt assembly. I also got started on building the cabinet with the side panels and rails at the front and back that support the trunnion frames:
While waiting for the glue to dry on the front and back panel, I got to work on the stand for the saw using pieces of scrap 1/2″ plywood:
Unfortunately, even though I carefully planned it out, I somehow managed to make the legs too short. A simple (but annoying) fix to extend them:
I made a video covering the stand build:
This odd shaped part is the mounting bracket for the third trunnion:
And is fastened to the front of the lift / tilt assembly with a hole for the lead screw:
Double washers with grease in between (Vaseline) and double nuts jammed, with the same on the inside, allow the lead screw to rotate freely:
With that much done, I could get it put on the stand to see how it looks:
I decided it didn’t look good, so I took the stand out and sprayed on three coats of water based exterior paint:
Meanwhile, I added more nuts to the lead screw to build it out past the front panel, then drilled a small hole for a locking pin:
The pin fits in a slot I cut on the back of the hand wheel:
I cut the slot using my miter saw, and I show that in the video at the bottom of this page.
Time to get the support frame for the third trunnion put in. I made sure the cabinet was square by clamping my framing square in one corner:
The third trunnion frame helps to support the heavy motor and was just rough cut on the band saw to the approximate radius. After it’s installed that curve needs to be recut to match the swing of the saw exactly, and I made a simple jig to hold my trim router to do this:
The jig is clamped to the third trunnion bracket to make the cut, and this action is shown in the video at the bottom of this page:
With enough of the curve cut, I made the trunnion from more of the slippery plastic and fastened that to the bracket:
I clamped a scrap of wood with a nail to the top of the trunnion frame to measure the locations of the lead screw and tilt angle control knob. The nail is the tilt axis of the trunnion assembly:
I used those measurements to mark the arcs that need to be cut out:
With the front panel in place, the upper slot is for the blade lift and lower hand wheel, while the lower is for the tilt angle locking knob and pointer:
More support for the top was added on the right side of the cabinet, but these are angled back to the side panel:
The angle is needed to allow the blade to tilt.
It’s mounted on a hinged platform that lets the motor rise and lower with the blade. The weight of the motor provides the tension for the belt:
Speaking of the weight of the motor, I knew it was going to be a problem. From the start I designed this saw with that weight in mind, and it’s the reason for the third trunnion. With the saw at 90 degrees, the motor is at the top of its swing, and putting a lot of downward force on the left side of the lift / tilt assembly.
To adjust the angle, I didn’t want the traditional side mounted hand wheel to endlessly crank, but wanted it to work exactly like the tilt adjustment on my old homemade table saw – loosed the locking handle, swing quickly to the new angle and lock it down again
The problem for this saw is that motor weight. I needed a way to stop the motor from dropping as soon as the locking handle is released, and spent much of a full day devising a method to do that. It starts with a bearing mounted on a 3/8″ bolt fastened to the back of the third trunnion bracket:
After MUCH trial and error, I arrived at this lever system that uses a trampoline spring to provide the upwards force. It’s a combination of the spring tension, the length of the lever on the bearing and the swing angle of the tilt assembly that makes this work:
With the motor at 90 degrees, the spring / lever mechanism is applying the maximum lift, and as it swing down that lift is reduced more or less proportionally. I could have spent some more time fine tuning it to get it closer to prefect, but this works well enough. Actually, as I said in this video, it works better than I thought it would.
I made the angle locking knob from a piece of 1/2″ threaded rod, plywood and solid maple and turned it on the lathe:
And with that much done, I took the cabinet out and painted that:
After two coats of paint, I gave the cabinet and stand two sprayed on coats of clear water based poly to finish it. Paint is durable, but not as durable as polyurethane.
From the top, mostly done on the inside:
The angle pointer is cut from a piece of 3/4″ plywood:
I’ll probably paint that I Build It blue, but leave the knob and hand wheel natural:
And that how far we are:
One more part left to this build and that will cover the top and support frame for the top, along with the power switch and blade insert.
Continued in part 3
Here’s the third video in the build series: