Setting up a miter saw to cut really sq.
I recently had a job that required cutting 8 – 45 deg miters in a distance of about 8″ . It was basically a 3.5″ molding around two layers of different size 3/4′ thick cherry.
The first miter looked good but as it progressed it would not stay on the line. So I checked the saw for Square at 90 and it was good. To make a log story short, eventually I checked at 45 and it was way out. So I clamped a piece of 6″ cherry to the fence and cut a 45 and with the piece still clamped checked for sq. off of the table and corrected it until it was sq. then went to the other side at 45 it was close but still out made corrections and back and forth 2 more times and now it is exact. This is the way I will use to sq. all of my chop saws. Does any one else do it this way or do you have a better way?
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I got kinda confused by your description, because square and 45* seemed to get interchanged. That being the case, I'm going to assume you're talking about making 45* miters (not bevels).
When I tune my miter saw, I check for the blade being 90* perpendicular to the table by cross-cutting a fairly tall piece of wood and flipping (rolling) one side over and see if there is any gap when I butt the two pieces back up together in a straight line.
Once it is square to the table, if I want to check the 45* miter setting, I cut a 45* on a pretty wide piece of wood, then roll one piece over and put the two together in a 90* fashion, check with a drafting square. If I'm about to miter for a frame and really need it to be p-e-r-f-e-c-t, I miter four longish pieces, and put 'em all together to make sure, because any error will be magnified when the frame is put together.
To check for an accurate 45* bevel, it's the same idea (reassemble to 90*), but I use a taller piece of wood to magnify any error.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
It is hard to describe, but, I too check square by first cutting a 1 x 6 jointed board flat and flip and check for gaps. Then I stand the board up and do the same test. I have done it this way for almost 40 years. This time after being assured that it was cutting sq. And I was doing several 3" tall miters in a row. So I put the tallest piece of jointed wood that I stould up against the fence and clamped it so it did not move. I my case I can stand up a 1 x 6. And cut it at 45 and then with my 6" sq. set on the table and up against the face of the 45 cut, and it was out of sq. 1/16 in 6", which in my way of thinking is totally unacceptable. Then I put another 1 x 6 on the other side and moved the blade to cut 45 on the other side and it was also out 1/16 but of course the other way. So I had to re-square the saw ; but this time not at the 90, but at 45 on each side. The next time you are using the chop saw clamp a board to the fence and cut a 45 then with it still clamped put your sq. up to it and tell me if is sq. I will bet it is not. I have 4 miter saws that I assumed were cutting sq. and after this experience I checked them and were all off.
'scuzzzze me for being a pain in the behind, but it would help if you keep the "square" and the "45" straight in these conversations, LOL!
I simply don't depend on a square to tell me if something is 90* or a drafting triangle to tell me if it's 45*. That's the starting point, but the final check is the cut itself, via the same test we discussed. Between not-so-perfect eyes and no budget for a Starrett square, it's just better to use the cuts.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
... Between not-so-perfect eyes and no budget for a Starrett square, it's just better to use the cuts.
**********Jaime, look on E-bay or check your local pawn shops. I've acquired several Starrett, B&S and Mitutoya instruments and squares that way, at a lot less than Fastenal or other retailers charge.Last purchase was a set of three machinists combination squares for less than $60US, including shipping. That's the cost of one Starrett twelve inch square with only the head, no protractor or Vee device.Leon
"set of three machinists combination squares for less than $60US" What brand were they? I've yet to find a combination square that was really square -- 2 new and several that were in auction lots with a bunch o' other stuff.
I've been using a drafting square for checking most stuff, and I have a couple of custom-made, laser-cut squares with degree lines that are handy for setup. I would like to get a quality combo-square, so I'll keep my eyes open!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
What brand were they? I've yet to find a combination square that was really square -- 2 new and several that were in auction lots with a bunch o' other stuff.
*******************Two were Starrett, one was Mitutoyo. All had been well cared-for and are in calibration.Machinists combination squares can be calibrated/adjusted; usually a machinists supply will know where, or offer the services. It's been my experience that they seldom need it. Calipers, on the other hand, do require it periodically.I've never seen a "contractor grade" combo square that was actually square, even new out of the box. Starrett, B&S, Mitutoyo -- all their scales are engine-divided. Stanley, Empire, etc are stamped. The difference between a ten-dollar square and a forty-dollar blade for a square. If you've a choice, I recommend the satin finish blades, IMO they're easier to read than the chrome ones.Leon
Thanks much for the info, Leon. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
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