Is there an easy way to find top dead center of a TS blade?

[Rich Engelhardt]

Yesterday I was making some 5/16" rabbets.
As I was going through all the trial and error routine, I couldn't help thinking there has to be an easier way to find the top dead center of the blade(s).

Any tips?

[Philip Rodriquez]

The multi-jig from Oneway is what I use if I need to get an exact number.

[Bill Huber]

I am not sure this is an easier way, it is the only way I know to do it.

I just use my height gauge, set it to the height I want and then move it back and forth as I raise the blade. When it just touches the blade that's it.

[Jamie Buxton]

I do Bill's approach, but do it slightly differently. I set the guage, set the blade high, and then drop the blade until the guage hits the table. I can rotate the blade back and forth while I'm dropping it to find top dead center.

My guage is a micrometer -- the tail section.

[Bob Lang]

Draw a line at the height you want on a scrap of wood about a foot long, parallel to the edge. Set it on the saw table between the blade and the fence (with the fence backed out of the way). Squat down so your eyes are just above the table top and watch as you raise the blade. Rotate the blade by hand and TDC will be obvious.

Bob Lang

[Howard Acheson]

>>>> I set the guage, set the blade high, and then drop the blade until the guage hits the table.

That can sometimes lead to bad measurements. It's best to always adjust tooling against gravity. There is slop (correctly know as "lash") between the adjusting gears. As you adjust down and then lock the adjustment, blade height assembly may not be at its lowest point. When you start the blade the blade will drop the amount of the lash. Adjusting up against gravity will result in the height being locked at its lowest point so the assemble will not drop further when the machine is started.

Even the toolmakers in the shop I ran adjusted their tooling against gravity.

[Richard Dooling]

Hey Bob,

That's pretty good. Seems obvious now that you've posted it.
.

[Floyd Mah]

Here's an easy way to get the exact blade height. Cut a sample dado on a scrap. Measure the depth of the cut. If you are too high or low, note how much you are off. Then place your scrap on the top of the blade, shouldn't be in the previous cut. Now, using a dial gauge (pick up a cheap one at Harbor Freight), place the probe tip on the wood scrap just over the blade position and raise or lower the blade the necessary correction. Now you have adjusted the height as closely as you can for woodworking. It doesn't matter if you are TDC on a tooth or not, you just need to know if the blade has gone up or down the correct amount.

[Aaron Berk]

I installed a digital height height gauge on the trunnion of my GO605x with the remote display magnatized to my fence rail.

It works perfectly for this EXACT operation, and it's the reason I did it.

For me, I just zero the blade to a reference surface and then watch the height gauge. Works like a champ.

[Bruce Elasik]

Floyd ----- Exactly!

[mreza Salav]

Along the same lines as Bob said but instead of looking at the blade and trying to figure where the top of the blade
is I'd measure the depth I want to cut from the edge of an scrap and draw a line on the edge. Then clamp that piece to the fence as a sacrificial fence;
lower the blade and bring the sacrificial fence over the blade so that half the thickness of the blades cuts through the scrap. Start the saw and raise the blade
(slowly) until the arc that the blade cuts his the line.

[glenn bradley]

I wonder if Rich isn't asking how he would know that he was measuring at a tooth that is centered along the arc of travel? I picked up a tip somewhere; with the blade laying on the bench I draw a line from 12-o'clock to 6 and from 9-o'clock to 3. Like a big plus sign tooth-to-tooth. Now when I am picking a spot to measure the height, no matter what method I use to measure it, I know I am TDC when the line is perpendicular to the table.