I have a Craftsman 10" CMS, and it doesn't cut accurately. When it is off
and I lower the blade, it appears to be square to the fence. I checked it at
45 deg with a speed square and the blade was at 45 deg. However when I
actually cut something, the cut is a few degrees off. The throat plate slot
also now looks like a V.
It has done this ever since I owned it, but when I first started using it I
primarily used it for rough cutting so I didn't really care. Now that I am
getting more involved in woodworking, it's an obvious issue.
Any advice on where to start looking for the problem?
Lets look at it again,you check for accuracy of 45degrees when the blade is
staionary,right so therefore when you cut the 45degrees its out by a few
Does this not tell you something?
It tells me that theres excessive play in the motor shaft.
I've got one out in the garage I had a problem with. I could get it to cut
dead on 90 degrees and it'd be off on the 45. Get it set for 45 and it'd be
off on the 90. Get it good on one side 45 and the other would be off. I
fiddled with that stupid thing for a month, never did get it right. It's
locked in at 90 and sitting on a bench in the garage. It's a good saw other
than that. The main reason I don't buy Craftsman any more is the service
people in this town suck. They had it for a week and couldn't get it right.
Sounds like the same saw I have, not bad but not great.
I first started with a decent blade by Freud. That solved my not getting a
decent cut problem. Then I tackled the actual tuning for square and angular
cuts. Ended up taking the whole setup apart and putting it back together
checking and rechecking anything that might effect the squareness of the
cuts. Spent almost two days on it but it does a pretty decent job. I also
built a station for the saw as well so it does not get moved around and is
somewhat protected from getting knocked about. My cuts are 100% better as a
result. My next saw though will likely be a Dewalt 12" SCMS equivalent or
Check the end play of the motor shaft. I have a
circular saw that I could never get a straight
cut, using a good straight edge. The saw would
want to move away from the straight edge. Adding
a 0.010" washer eliminated most of the problem.
Will need to make and add a 0.003 to 0.005" to get
to less than .001 end play.
I'm afraid that your problem may be the 4th word above
"Craftsman". That word used to mean something quite
significant a long time ago, but that was then and this
It is really quite sad actually. I have seen that name on
pure junk. Quite sad.... really....
Well, the V shape slot in the throat plate suggests your blade isn't
parallel to the rip fence (i.e. miter gage slots). Some loosening of
bolts and tapping with a mallet can fix that. The circular saw cuts an
a straight slot, if it's at an angle. Depending on where on the oval
rides, you can get a range of cut angles.
Once that alignment is done, there are still issues you might have to
The motor -Vbelt tension and a little vibration can shift the set point
a little ways,
so it might be prudent to adjust/make a test cut/readjust.
There are some good treatments of the general table saw setup, like
Power Saws and Planers <http://www.taunton.com/store/pages/070127.asp
Mine has a ?toothed? or ?ridged? belt between the motor shaft pulley and the
arbor pulley. I think the idea is to save the motor or operator during a
sever binding situation. Maybe it is just for speed control. belt cost a
$14 when I had to replace it.
Mine is an old model from Milwaukee probably 30+ years old. Still cuts
within a half degree of accuracy on all settings and dead on if you gauge
it. Only problem with it is that it uses a 9 1/2" blade, sort of limited
selection of those around here. The belt I got for it was for a Delta saw,
so maybe there are others like it out there somewhere.
Oops! I zoned out on the Compound Miter Saw specification... thinking
it was a table saw issue. And don't bother with the book, it covers
and table saws, even bandsaws, but not compound miters.
The basic geometry still holds, though; you need both the alignment of
the blade (the
angle that was checked) AND the alignment of the plane through which it
sweeps when the saw makes a cut (which is harder to check) as well as
various wood-holding pieces.
Another suggestion (worn bearings) seems less likely; the mechanisms
I've seen have
a large lubricated journal bearing, it'd take a LONG time to wear down.
Cracks in the
bearing housing could lead to the same effect, though (inspect with a
After you check for excessive play as already suggested and ruled it
out forget about the speed square.
Set the tilt of the blade to zero and cut the end off of two pieces of
wood (2x4 is good size) and then butt the cut ends together on a flat
surface like a table saw top. If there is no gap then your saw is
truly at zero. Make adjustments until you get this correct. Then tilt
the blade to 45 degrees and go through the same procedure to set the
Then tilt back to zero and turn the table to zero and get a firm seat
on the detent and lock it down. Again, cut two pieces of wood and do
the butt test to see if you are at zero and adjust the fence as
necessary to get this right. Make sure you cut the ends off of both
pieces using the same side of the fence. Once this is done you may or
may not be able to adjust the 45degree detent, probably not, but
everything else should be right.
I also use a similar technique to adjust my TS and it is far more
accurate than trying to use a square on a saw blade and either miss the
teeth or align only using the teeth.
Good plan... what we forget sometimes is that it's the project that has to fit
together, not what the simple or high-tech tools say that the alignment is...
I have the same saw, if it's got the laser crap and the extension for the
Mine started doing what you describe at about a year old... turned out to be a
pretty simple fix, the nut and lock nut on the saw pivot had loosened, allowing
play, which made the blade-to-insert variable...
I tightened it too much on the first try and locked the pivot... trail and
errors on adjustment was worth the time as it's been cutting very accurately for
a couple of years now.. and yes, it's made in China... check the label.. *g*
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.