Thread: Sliding miter saw: how square is square?

Originally Posted by IdahoEv

2) Maybe the Craftsman just sucks and is incapable of producing cuts reliable enough for tight miters. If so, I should return it and spend the extra $300 for a Bosch or Dewalt. (I can't afford a Festool, sadly).



Thanks for any advice.

I vote for this option A good tool should be able to consistently reproduce a square cut with no visible variation.

Grab the blade and see how much play is in it. The whole mechanism should not move neither should there be any play in the blade. Also measure the fence for straight using a straight edge. I found that my fence had a bow in it which made for some interesting angles. It was fine for flooring but when I came to make precision cuts they were all over the shop.

John

Originally Posted by IdahoEv

I'm having trouble adjusting my new Craftsman sliding compound miter saw to my satisfaction. After several hours of effort, all my miters still visibly gap and test cut-offs (cut MDF, flip, cut again) vary by about 0.020". That corresponds to a variability in angle of my cuts vary about about 0.1° from cut to cut with no changes to the tool. Is that normal for a sliding miter saw?

at the lower price points I understand that that degree of error is pretty good

Originally Posted by IdahoEv

This is my first sliding compound, so what I don't know is which of these is true:

1) Maybe this is normal. All compound miters have a certain amount of slop, and accuracy/repeatability wouldn't be better even with any other saw. In which case spending another $300 would just be a waste of money.

2) Maybe the Craftsman just sucks and is incapable of producing cuts reliable enough for tight miters. If so, I should return it and spend the extra $300 for a Bosch or Dewalt. (I can't afford a Festool, sadly).

3) Maybe I just don't know what I'm doing. 0.020" difference from cut to cut seems like a lot to me, but what do I know?

I also vote for #2.

the thickness of cut taking off 0.2" as opposed to 1" and blade stiffness are also factors.

An option is to build yourself a couple of shooting boards for your most common angles and true the miter off the saw to the exact angle.

If you watch this video to the end. You will find his saw is out by 0.017" from a 12" board which is about 0.08 deg. So I don't think your saw is that far off. I think you could probably get a better saw like the Bosch Glider and it will probably have half the inaccuracy. How often you use the saw will justify whether it is worth the extra dough. I probably will myself.

The same guy is doing a 2 cut calibration and he only gets 0.004" difference which means it is 0.002" over the length off 90 degrees. Mind you he is using a Festool saw so you would hope it's pretty good.

If it's a cheap saw then this is pretty much par. My cheap ryobi slider is more rhombus than square, it's pretty much on rough docking to length duty till it dies.

Maybe it would be worth buying a second non sliding saw for precise type work, they would have to be more accurate and cheaper.

Originally Posted by Treecycle

The same guy is doing a 2 cut calibration and he only gets 0.004" difference which means it is 0.002" over the length off 90 degrees. Mind you he is using a Festool saw so you would hope it's pretty good.

Mine was 0.01" with the 2 cut method.

remember most of these saws are intended for builders and are not really precision tools.

In the day the electra becum ( now metabo) was the machine you got if you needed accuracy for picture framing or aluminium joinery.

very quiet Induction motor and when in adjustment very accurate, but a little short on the depth of cut.

I used to build equipment cases with mine..... and that was joinery in aluminium extrusion.

cheers

Maybe it would be worth buying a second non sliding saw for precise type work, they would have to be more accurate and cheaper.

What is the best drop saw ( not SCMS) for accurately cross-cutting 300mm wide boards to within 0.2mm error, the error being difference between a true right angled line drawn across the board and the distances to each corner of the cut

seriously ya won't find a plain drop saw that will cross cut 300mm.

boards that wide better done on a table saw with a sled.

cheers

Thanks to everyone who replied. Based on this feedback, some at lumberjocks.com, and a bunch of my own research, I returned the Craftsman and bought a 12" non-slider Dewalt. I used it all weekend and was pretty happy with the results.

Originally Posted by Yanis

I vote for this option A good tool should be able to consistently reproduce a square cut with no visible variation.

When I hand-tested a bunch of floor models, I found that I could deflect the cutting head 1/16" to 1/8" sideways on essentially all 10" sliders except the Bosch glider. The Craftsman was was worse than most, but not by any *huge* amount.

HOWEVER, the craftsman had a noticeably bowed fence, and when I checked two other saws of the same model they had exactly the same bow in the fence. So I think it's a manufacturing flaw. (See picture). 0.015" off over 6" on the right side of the fence is way too much for my comfort, so back the saw went.

I was briefly tempted by the Bosch, but the expense and huge weight were a turn off. Plus there were some reviews stating that sometimes the arbor isn't perfectly in line with and perpendicular to the axis of travel, and when that's the case the blade moves slightly sideways through the work and there's absolutely nothing you can do to adjust it. I decided for $650 it wasn't worth it.

So I a new 12" Dewalt non-slider. I didn't need the double-bevel, but it's all Home Depot carries and after recent tribulations I'm not ordering a saw online -- I need to be able to return it if there's a problem.

I used it to miter redwood 2x6's for raised planter beds all weekend and was quite happy with the performance. (Speaking of, that's why a table saw wasn't really an option for me for my current project. I was mitering the ends of eight-foot-long 2x6s, a pretty unwieldy crosscut on a table saw.) Thanks

Craftsman-miter-saw-problem.jpg

Finishing my last sentence: "Thanks so much to everyone who replied!"