Miter Saw Question

[Ian57]

Earlier this year I purchased a craftsman miter saw. After doing several test cuts I found the 45* miter cut when tilting the blade to be off. I adjusted it and got it close. but in my view no cigar. Recently I purchased the Wixey Digital Angle Gage. So I put the angle Gage on the saw bed and zeroed it. I then adjusted the saw blade angle till the DAG read 45*. Did a test cut thinking it would be very close. Well still no cigar in fact it was further out than when I first got the saw. So can somebody please explain why it is so far out. Oh sorry it was at least 2*. I have checked it to day with a friends angle gage, His gage reads same as mine. that is the bed is zero and the blade is 45*. But when doing a test cut it is still 2* off.
PS the work piece was clamped for the test cuts.
Cheers
Ian
Although I do not smoke I would love that cigar.

[LCHIEN]

first some terms:
the term Miter cut refers to moving the blade adjustment in the horizontal plane.
Bevel cut refers to tilting the blade
Compound cut refers to a cut where you are making both adjustments.

I read that you are makign a Bevel cut of 45° (BTW, hold the ALT key and then sequentially press 0176 on the numeric keyad to get the degrees symbol).

I have a Wixey gauge and I find it quite accurate in comparison to other digital protractors and reference angles.

So I can envision two problems - One is that your cut is really 2° off or maybe your measurement of the resulting angle is off?

How are you verifying that your cut is 2° off?
first of all is the bevel cut itself perfectly flat faced?
Lay the board on a flat surface, zero the gauge to the flat surface, attach flat piece of wood to the bevel face that is long enough (at least 3 inches) to fully seat the WAG and check the angle.

If the angle is good then you are OK.
If the angle is not good and the bevel face is flat, then your machine is probably flexing when making the cut. Or, the blade is not flat where you are measuing it (some have steps in the width, the carbide tips also stick out.) and you do not have the WAG on the blade parallel to the cutting angle.

Good luck.

[Bill in Buena Park]

Ian,
Is the stationary portion of the saw table slightly lower than the central pivoting table? If the wood is clamped to the stationary table and being elevated by a slightly higher central table, it could through the cut angle off.

[mpc]

With the saw off and unplugged: grab the blade and try to wiggle it side-to-side. Any play? Sloppy bearings or other excessive clearances inside the saw arbor assembly will result in lousy accuracy and poor angle repeatability. Any blade "run out?" Spin the blade (by hand - saw unplugged still) and watch the edge of it. Any wobble or apparent motion?

Using the wrong type of blade can lead to excess stress on the blade as it tries to make the cut; that leads to the blade flexing a bit. Moving the saw very slowly into the workpiece reduces this... give it a try and see if your 2 degree error gets smaller. If so, a full kerf blade - if you are using a thin kerf one now - should help.

And as Bill in Buena Park mentioned, if the work surface of the saw isn't flat across the entire surface then the workpiece will either be angled when you grip it or it can flex if it's not supported underneath by the blade. Not much you can do to adjust this (on most miter saws I've seen) if this is a problem.

mpc

[cabinetman]

What hasn't been mentioned is how you operated the saw while making the cut. Miter saws and RAS's are designed to be adjusted to make certain cuts with being equipped with bearings, washers, nuts, bolts, bushings, etc enabling the desired movement. How exact the saw does what it's set to do during the cut could be overcome and changed by shear force by the operator.

Many tools/machines hold their settings when their movements are not forced or "muscled". A light guided hand can make a difference. The problem could be as simple as improper or erratic operator input.

.

[capncarl]

This sounds exactly like a discussion we were having earlier this month about a simular saw problem. The machine is not engineered to provide the tolerances that the customer expects. You may be able to adjust out a lot of the error and even get it where you are satisfied, but the fact remains that the manufacture produced and sold a machine thats precision matched its selling price. Don't think for a minute that most of the cheaper woodworking machines that are made offshore, or even the ones made here have very much reasearch and developement on the angle and bevel settings.
capncarl

[JimD]

My current CMS is a dual bevel Hitachi 12 inch. I rarely use the bevel capability because of the difficulty in setting the bevel angle. Usually I stand the wood against the fench and miter it. I do that mainly because it is far easier to set a miter angle than a bevel angle.

The least accurate things about my tools are the wood I cut on them and the operator of the saw (me). Wood is seldom really flat and of consistent thickness. That can make miter angles challenging. And C'man already mentioned the operator input. Especially on the RAS it makes a big difference. My CMS seems more rigid but my technique can still throw it off. A negative hook blade helps on both. A positive hook makes the saw want to pull itself into the wood which can result in inaccuracy.

Jim

[sweensdv]

At one time I had a Craftsman CMS and it was the worst tool in the shop. Kicked myself numerous times for buying it. I had similar problems with it that you describe you're having with yours. I was able to determine that the problem was with the saws design. When making a bevel cut at almost any angle the saws table would flex a bit if the blade was not lowered into the work piece at the angle of the bevel. Just about any straight up and down pressure on the blade housing while making the cut would cause the cut to be off by a few degrees. I solved the problem by getting rid of the saw. I also was able to duplicate the table flex with Ryobi and Ridgid CMS's.

[cabinetman]

At one time I had a Craftsman CMS and it was the worst tool in the shop. Kicked myself numerous times for buying it. I had similar problems with it that you describe you're having with yours. I was able to determine that the problem was with the saws design. When making a bevel cut at almost any angle the saws table would flex a bit if the blade was not lowered into the work piece at the angle of the bevel. Just about any straight up and down pressure on the blade housing while making the cut would cause the cut to be off by a few degrees. I solved the problem by getting rid of the saw. I also was able to duplicate the table flex with Ryobi and Ridgid CMS's.

Sorry to hear you didn't like the Craftsman. I've used many CMS's and like the Craftsman best. I haven't had a saw that couldn't be brought into good working tolerances. Of the brands I've had all were very good, but the Craftsman just had a better feel.

Knowing how to adjust, maintain and use saws like that can make a difference. When saws like that are used on a regular basis you become familiar working with it. Many users were never taught the ins or outs of using their tools and machinery.

Where are you located? If I have the ability to visit you, I would be happy to spend whatever time it takes to help you out.

.

[capncarl]

Hey fellows, I was not particular jumping on the mans Craftsman saw because it is probably suited for the purpose intended by the mfg. The average homeowner buys and uses this kind of equipment to build a garden shed or lop off the ends of a board and make a dog eared fence, not build fine cabinets. Most everyone here finds that finer built equipment produces a precision or more desireable finish. If that was not the case then half of the members here would still use their BT's and would not have purchased more expensive table saws. What I have always liked about this site is that it's memebers come together to share their knowledge and help each other work with their tools and how to solve the tools problems. We have all learned that some problems are like warped wood and just can not be solved, just worked around.
On my Hitachi compound miter slider to get a precision cut I have to set it where I think the desired angle will be and make a cut on scrap wood and measure that cut, then adjust the saw until I am satisfied with the cut. Then cut all the angles necessary before moving the saw because it is difficult to find that exact spot on that tiny little scale.
capncarl

[cwsmith]

I bought a Ridgid 10-inch CMS many years ago (2004 or 05, IIRC). While I like the tool for some kinds of work (2 x 4 framing, mitering molding and trim, and general 90-degree cut-off work), I've found it totally inaccurate for precision bevel cuts, like you mention with your Craftsman.

If the stock is narrow enough, I simply stand it on edge and cut it like a miter. But as a "bevel" with the stock placed flat on the bed, no success.

At the time, I did a lot of reading and also posted on the forums. All to no avail, and I simply could never get the problem resolved. I did read one article (can't remember where) that said the CMS simply could not accurately cut a bevel, as the pivot design and other mechanical adjustment allowed too much flex. Also that a thin-kerf blade would flex enough to throw off the cut, regardless of adjustments.

While I can't pin the problem down to anything specific, my experience tells me that the above statement is perhaps correct. I now leave bevel cuts to the domain of my RAS, which has never presented this problem. It also leaves me to think that a Sliding CMS (SCMS) would also provide for more precise bevel cuts.

The question of course is whether this bevel cut challenge is only on some models, or across the board. If that is the case, that it's only particular models, then the problem surely must be in a poor design or assembly. For me, further investment of time simply wasn't worth the effort because I have my RAS; and, the Ridgid CMS, is now relegated to "carpentry" tasks.

CWS