RE SCMS Accuracy

[Rob Keeble]

Ok all so I got a Dewalt SCMS 12 inch and having seen someones zero clearance insert i decided to put one in my own saw.
As always while doing this kind of work I thought I would check out the accuracy of the saw and see if it needed adjustment since I had never done that since time of purchase.

So now I have the insert and checking the angles with a digital protractor I come to the question of how accurate is realistically achievable on these machines.

Anyone want to chime in here about what would be a realistic tolerance to settle for.

I now realize why some guys have the Incra type mitre gauge for the TS.

Thanks.

[Bill Lantry]

Rob,

I have a dewalt 708. It's a great saw for construction projects... in fact, I love it. I can throw a 4x4 on it and cut where I want. It'll take a 12' 2x4. I can even put a dado blade on it, and make lap joints as I go. If I'm making a cut that's, say, 3' 6" and a fat 3/8", it's the best thing since sliced baguettes...

But for fine furniture? Picture frames? Forget it. That's not what it's designed for. I gave up on that after just a couple cuts. It's a saw designed to ride in the back of a pickup, and do framing and trim work at the jobsite. Does it great. I've known guys who say things like "This ain't no piano we're building"

It's their kind of saw...

Thanks,

Bill

[Matt Hutchinson]

Well, a SCMS or typical chop saw both can be set up to do fairly accurate work. However, the natural forces of the blade push the work piece sideways as it progresses through the cut, so to increase accuracy set up a good fence and use stop blocks if possible. This greatly improves the situation, but I still wouldn't use it for furniture making as Bill said. Also, the 12" blade contributes to its inconsistency.

I generally prefer to use the tablesaw for as many finish crosscut operations as possible. For some reason it just seems to produce more consistent results, even without stop blocks on crosscuts.

Hutch

[glenn bradley]

My CMS sits on the MSUV behind the jointer. When I need to do that kind of cutting, it is a joy to use. Would I make frames or miter jewelry box parts with it? No. That's a job for a good miter gauge and / or sled around my shop.

[tod evans]

rob,
i use sliding mitersaws everyday.....put away your protractor and measure what you`ve cut.
when tuning up a chopsaw i like to use mdf that`s the full width of the saws crosscut capability......
first true to 90º by cutting a board then put the other edge against the fence and cut a sliver about 1/4" off the end.......using calipers measure each end of your cut......a saw set at 90º will be the same......any error is magnified x2......adjust the fence to correct any error.
i`ve never seen a name brand saw (even the cheap ones) that if 90º was on the miter settings where off.......all of the bases are cnc cut with tapered slots so unless somebody has drug the stylus over the detents they should remain true.
after you set the saw up then it`s all how you hold your tongue

[Bob Ross]

Rob,

When Lowes was clearing out the DW 712 (8.5" slider) I went hither and yon trying to find one. I had a copy of a receipt another forum member posted and it was something like $225. The last place I checked was a store 12 miles from me. None in stock, but the hardware guy looks me up and down and says "woodworker?". I said "yup". He said " Well, I've got one at home NIB that I bought when the clearance started. I'll sell it to you for $150 'cause I'll never use it." I swear I nearly tore the pocket on my jeans getting that money out. I immediately bought a Freud tk 60 tooth, -5* blade and it's been bliss since.


I know miter saws are not considered precise and I agree that not all of them are. I suspect that some of the bad rap comes from operator error. Saws without a soft start make it hard to hold the workpiece perfectly still and as has been said, pushing a blade through wood at 45* is going to want to move the wood sideways. That said, I am using my slider for cuts that I would not have thought possible. Sombody mentioned a dado on a 708. I have put the Freud box joint cutter set on my 712 to do half-laps. The blade-holding bolt needs to be 3/16" longer before I try it again, but I really like having the cut "up".

[Mark Kosmowski]

Would precision be increased if the workpiece was securely clamped to the fence instead of trusting to hand pressure?

[tod evans]

Would precision be increased if the workpiece was securely clamped to the fence instead of trusting to hand pressure?

when a human is involved there`s no pat answer........the tools themselves are by and large accurate, in fact it`s pretty rare to find even a cheap mitersaw that`s "off" out of the box.
i do better with hand pressure.........you might do better with a clamp......and somebody else might do better another way?
if a person wants to learn how to drive any tool with precision it takes practice.

[Rob Keeble]

Thank you all especially Todd for the really practical advice and wisdom. My thoughts have been confirmed and now this saw which is still relatively new will get put up for sale.

Like Stu I have now discovered how little space I have in my "huge shop" Thats whateveryone that comes to my place says just because it takes up half the backyard.

But a SCMS has such a width that when you are finished accomodating it on a cabinet down one side of the shop you have used up a great deal of space.

Considering that I dont intend doing much more construction type work in my shop, I will used the saw for finishing my basement and then it will be bye bye.

I bought this saw without sufficient knowledge and in typical guy fashion did not want to be caught short.

But since then I have learnt one heck of a lot more and now realize for my shop use this was a big mistake.

It is pretty accurate but for exactly what it was designed to do.

Thanks all for the feedback.

[tod evans]

rob,
i don`t use a 12" slider........my 10`s aren`t broke
as far as keeping a chopsaw in the shop though i`d figure out what space you can dedicate to one even if you store it elsewhere.
10" non-slider saws are pretty affordable and if they`re outfitted with a quality full-kerfed blade will make your life much easier.