SCMS

[delboy47]

I recently acquired a sliding compound mitre saw after my previous mitre saw (chop saw not sliding) gave up the ghost.
I also recently saw a short video where the operator using the same saw was cutting on the push stroke (i.e. front to back).
The spin direction of the blade is such that the front edge (nearest the operator) is moving downwards and therefore the back edge moving upwards.
My logic such that it is the cut should be done on the pull stroke (from the back to the front) so the blade is cutting down into the timber whereas cutting on the push stroke means the blade is cutting upwards with the tendency to lift the timber off the bed.
So, is my logic correct or does it not matter provided the timber is securely held down onto the bed?
I must admit I have tried a bit of both ways but am unsure about this.
Thanks Guys
Del

 

[NazNomad]

Because of the way it's constructed, pulling a SCMS might cause it to ride up on the workpiece and take a leap at your pinkies.


Push a SCMS, pull a RAS.

 

[Woody2Shoes]

FWIW the instructions with my large DW SCMS very clearly show cutting on the push (down, then away from you), not the pull. As I understand this, as already pointed out, the aim is to try and reduce (not eliminate) the risk of kick-back/up. Remember there's no riving knife to help avoid the blade getting 'pinched' by a badly-behaved workpiece. I also believe that using a blade with the correct tooth geometry is important for similar safety reasons. Cheers, W2S

 

[Doug B]

I use a SCMS quite a lot & whilst I prefer to cut on the push stroke there are occasions where cutting on he pull stroke will give a better finish such as cutting MFC or gloss faced MDF.

 

[MrYorke]

Or turn the work over and cut of the push stroke

 

[monkeybiter]

Or turn the work over and cut of the push stroke

Only if it's a narrow piece and you can drop below it before the blade gets to it, otherwise you'll break through from 'under' the finished surface.

 

[blackrodd]

If you pull the saw towards you, the blade can easily keep coming at you, and clip or stall and be difficult to stop on wide boards, etc which is it's prime function, cross cutting wide boards.
Pushing the saw away from you will, as you say try and lift the back of the board especially when it "clips" or jams the saw blade and it does make you wonder where you're fingers could be.
The first point is for safety the machine should be safely fixed to a bench or similar for either of the above eventualities.
Keep sharp blades fitted, blunt blades can cause many problems including snatching and grabbing!
Also, See what the saw manufacturer recommends, pulling or pushing, or whatever makes you the user feel safest.
Some even provide clamps.
And when cutting a nice wide piece of 2" oak, do not attempt to cut the full depth,
I would take up to 3 bites, And I usually pull towards me as a traveling head cross cut saw, usually is worked.
Regards Rodders

 

[shed9]

The actual guidance from some manufacturers for using an SCMS is to cut on the push stroke and wait for the blade to come to a complete stop before lifting up again.

 

[blackrodd]

The actual guidance from some manufacturers for using an SCMS is to cut on the push stroke and wait for the blade to come to a complete stop before lifting up again.

What model was that advice on please?
Rodders

 

[shed9]

The actual guidance from some manufacturers for using an SCMS is to cut on the push stroke and wait for the blade to come to a complete stop before lifting up again.

What model was that advice on please?
Rodders

Festool certainly give it for the Kapex and I understand that Bosch have issued the same advice as well for their saws.

The approach is two fold, to help prevent kickback and retain the quality of the cut itself. If you leave the blade to come to a rest in the cut it is less likely to damage the fibers on its exit.

 

[Doug B]

Or turn the work over and cut of the push stroke

But what if both sides need to show a clean cut?

Sometimes it's necessary to cut partway through the board on the pull stroke then cut all the way through the board on the push stroke so giving a clean cut both sides.
If anyone is so worried about a board moving or lifting use the work piece clamp, they're standard equipment with most SCMS

 

[Zeddedhed]

I've got a Bosch glide thingy (the big one) and it's a great saw. The advice given is always clamp work, cut on the push, let the blade stop. With my 1st fix heritage I gleefully ignored all this and wondered my my cuts were not of top quality.
Once I'd followed the advice given I now get excellent cuts. I also sometimes put a piece of sacrificial 6mm MDF under and behind the workpiece.

 

[shed9]

I've got a Bosch glide thingy (the big one) and it's a great saw. The advice given is always clamp work, cut on the push, let the blade stop. With my 1st fix heritage I gleefully ignored all this and wondered my my cuts were not of top quality.
Once I'd followed the advice given I now get excellent cuts. I also sometimes put a piece of sacrificial 6mm MDF under and behind the workpiece.

Me too, I also had a fair bit kickback on my Kapex and never really experienced it before on my other saws. It takes some getting used to having the patience waiting an extra few seconds on every cut for the blade to stop (it's harder then you think) but the results are definitely better IMO.

 

[Woody2Shoes]

An interesting read about how blade geometry affects safety and quality of cut in different situations - a "California triple chip" sounds good enough to eat!

http://www.carbideprocessors.com/pages/ ... ngles.html

 

[Grahamshed]

I also have the 'Bosch glide thingy' and use the push cut and wait methoud. The cut quality, even through 4 inch oak burr is a thing of beauty.

 

[Rorschach]

I tried both pull and push on laminate floor with my saw. Pull cuts were harder to control and worse cut quality.

 

[delboy47]

Thanks for your replies and comments Guys.
Looks like a mixed bag. I have experienced kickback a couple of times so maybe I need to take things a little slower and stick to cutting on the push strokeand always using the hold down.
Thanks
Del