SCMS Pull or push?

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OK, I have just been watching a free DVD that came with a magazine. In it the guy was cutting using a SCMS. I always pull out, drop down and push cut.

This guy was pull cutting through the material. Surely that is wrong...
 
Surely that is wrong...

It surely is!

A radial arm saw forces the wood down and against the back fence on a pull stroke because the head can't move upwards away from the cut. Pulling is the correct way to use a RAS.

A SCMS, by design, pivots upwards. There is nothing mechanical to stop it from grabbing the workpiece and coming towards you faster than you intended.

I have a nasty scar on my thumb where my SCMS caught in a cut due to wood tension (and maybe incorrect positioning) and flew up and towards me. The hand that was on the handle stayed relatively still while the blade came up. The guard didn't have time to come down and cover it.

-JR
 
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Uh-OH! :eek: I want to hear more on this subject. Being untutored, I assumed it was drop and pull and do it that way. Albeit, I don't like that the blade tries to 'race' through the wood. Need a new negative rake blade. Continue elucidating guys.
 
it is probably not a good idea to do it that way although i've seen many people do it with no problems.

what i do, is let the blade score the board on the way towards me just cutting about 1/16 or 1/8, then plunge down and finish the cut pushing away. i seem to get a cleaner cut that way because the scoring keeps the blade from chipping up on the top of the board

chris
 
what i do, is let the blade score the board on the way towards me just cutting about 1/16 or 1/8, then plunge down and finish the cut pushing away. i seem to get a cleaner cut that way because the scoring keeps the blade from chipping up on the top of the board

chris

That's the way I do it, too. Less tear-out.
 
I once had the blade loosen doing it that way (pull that is), so now I always drop and push like most of the other posters.
 
I have nnot had much experience with such a saw, but the few times that I have used one, I pulled. From what I read hear, it appears that I was using the wrong technique. :eek:

Chris, I like the scoring technique that you described and will remember it the next time I use a SCMS.
 
From the Ridgid SCMS manual.

Never make a cut by pulling the saw toward you
as the blade can climb on top of the workpiece
and come toward you. Failure to heed this warning
could result in serious personal injury.

TO SLIDE CUT
See Figures 32 - 33.
The sliding feature will cut workpieces 13-1/2 in. wide by
3-1/2 in. thick. With the saw off, pull the saw arm forward.
Turn the saw on (let blade reach maximum speed),
then push the blade down on top of the workpiece then
back toward the rear of the saw to make a cut. Cuts are
made by: (1) pushing the saw blade away from you and
toward the bevel scale at the back of the saw stopping
when the full rear position has been reached after each
cut. When the saw is running (turned on), NEVER pull
the saw blade toward you or toward the front of the saw.
 Raise saw arm to its full height.
 Place the workpiece flat on the miter table with one edge
securely against the fence. If the board is warped, place
the convex side against the fence. If the concave edge
of a board is placed against the fence, the board could
collapse on the blade at the end of the cut, jamming the
blade. See Figures 48 - 49.
 When cutting long pieces of lumber or molding, support
the opposite end of the stock with a roller stand or with
a work surface level with the saw table. See Figure 41.
 Align the cutting line on the workpiece with the edge of
saw blade.
 Loosen the slide lock knob by turning the knob counterclockwise.
 Grasp the stock firmly with one hand and secure it against
the fence. Use the optional work clamp or a C-clamp to
secure the workpiece when possible.
 Before turning on the saw, perform a dry run of the cutting
operation to make sure that no problems will occur
when the cut is made.
With the saw off, grasp the saw handle firmly then pull
the saw forward until the blade arbor (center of the saw
blade) is over the front of the workpiece.
 Depress the switch lock with thumb then squeeze the
switch trigger. Allow several seconds for the blade to
reach maximum speed.
 Slowly lower the blade into and through the front edge
of the workpiece.
 Push the saw handle away from you and toward the bevel
scale at the back of the saw.

Fig. 32
SLIDE CUT
Fig. 33
SLIDE SAW ARM
FORWARD THEN
PUSH DOWN
PUSH
BACK
 Release the switch trigger and allow the saw blade to
stop rotating before raising the blade out of workpiece
and removing the workpiece from miter table.

From the Makita LS1212 manual

2. Slide (push) cutting (cutting wide workpieces)
Loosen the knob counterclockwise so that the carriage
can slide freely. Secure the workpiece with the vise. Pull
the carriage toward you fully. Switch on the tool without
the blade making any contact and wait until the blade
attains full speed. Press down the handle and PUSH
THE CARRIAGE TOWARD THE GUIDE FENCE AND
THROUGH THE WORKPIECE. When the cut is completed,
switch off the tool and WAIT UNTIL THE BLADE
HAS COME TO A COMPLETE STOP before returning
the blade to its fully elevated position.
CAUTION:
Whenever performing the slide cut, FIRST PULL THE
CARRIAGE TOWARD YOU FULLY and press down the
handle to the fully lowered position, then PUSH THE
CARRIAGE TOWARD THE GUIDE FENCE. NEVER
START THE CUT WITH THE CARRIAGE NOT FULLY
PULLED TOWARD YOU. If you perform the slide cut
without pulling the carriage fully or if you perform the
slide cut toward your direction, the blade may kickback
unexpectedly with the potential to cause serious
PERSONAL INJURY.


I am not sure if those of you with questions about this type of saw have ever had the chance to read the manual or not but I fully believe that this saying will save many people form getting hurt.

"Before using any power tools let's take a moment to talk about shop safety. Be sure to read, understand, and follow all the safety rules that come with your power tools. Knowing how to use your power tools properly will greatly reduce the risk of personal injury. And remember, there is no more important rule than to wear these, safety glasses."


Norm's Safety Speech
 
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Thanks for the manual excerpts Bart. My excuse :eek: for not reading how to use a SCMS the few times that I used one is that I was using a saw owned by someone else and they did not provide a manual. :eek: I know that is a flimsy excuse :eek: but I am sticking to it. :eek:

By the way, I am someone who always does read the manuals that come with the tools that I buy.
 
Thanks Bart. I'm going to print out and save your post and re-read it several times. I'm also going to practice the technique so I don't fall back on my old habit. I believe I just assumed it was a pull cut from, as a child, watching my father with his radial arm saw pulling to cut. FW comes through again. :thumb:
 
I'm also going to practice the technique so I don't fall back on my old habit. I believe I just assumed it was a pull cut from, as a child, watching my father with his radial arm saw pulling to cut.

Most habits are very difficult to break but for some reason the "pull cut" habit from my RAS, which I used for over 30 years, did not transition to using my sliding miter saw. Strange but true. I hope that you find the same thing.
 
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