How accurate should a SCMS be?

[matthew]

Thinking about buying a new SCMS sometime. (Actually, thinking about buying lots of things, whether I actually do or not is another matter )

I have a fairly cheap SCMS, got it ages ago from B&Q - it's more than paid for itself doing studwork, decking etc so I've no real complaints about it, but it's a bit lacking for doing furniture work. I bought a finer blade for it which has helped, but I'm not very confident in its accuracy - the whole thing seems to have play and/or flex in pretty much every axis so I can't really trust it for spot-on crosscuts.

It's very handy and I use it a lot (perhaps because bar jig, it's the only saw I have, no table/band/circular yet ) so I'm thinking I may get a better one. I was wondering how good and rigid a decent SCMS is? Is it wishful thinking, does the S and/or the C of it inherently limit it? Is it better to get a CMS (or even a MS) and find another solution for longer crosscuts? Or is a good SCMS much more accurate than I'm used to?

And any particular recommendations?

MTIA, Matthew

 

[Scrit]

Well for doing modern wide kitchen cornices and the like I don't think the issue is absolute accuracy (partly because I wouldn't give you tuppence for the accuracy of the scales on most SCSMS saws), but more of rigidity, i.e. how much the frame and/or bars flex in cut. I reckon that a large 10in or 12in straight chop saw will be more accurate than an 8-1/4in SCMS simply because it is more rigid. I suppose it all depends on how wide you need to cut, but if you start looking at the big deWalts (like the DW718) or Makitas (like the LS1214) for example you'll find the 12in saws have very little capacity over the 10in ones - but the price difference is enormous. Believe it ot not I still use a 10in flip-over saw for most chop saw work (no sliding facility there) as it can just cope with most of the mitres I do. The only thing I would say is stick with the big name brands: deWalt, Makita, Bosch, Scheppach, Metabo (Elektra-Beckum), Hitachi, etc and you'll be better served than buying a cheap "no-name" device

Scrit

 

[engineer one]

scrit seems that it is getting past your bedtime on a sunday, customer
feedback is something that seems not what most manufacturers care
about these days.

however, i would say that the dewalt 708 i use has proved a sensible buy,
being pretty accurate for cross cutting, and also (phew )
reasonably light. but boy if only we could figure out a sensible way to
collect most of the dust. :lol:

i think that we all expect too much for angles other than 90
of all our saws. if you are doing lots of repeats, then make a sled
to be sure it is accurate, don't trust the detents all the time
but then how many walls are square???? :twisted:

paul :wink:

 

[Scrit]

I've had a Makita LS1013 for a long time now, but I wouldn't describe it as accurate - rigid, yes - but not accurate. Don't recall anyone I know with DWs saying much different about theirs. I have tried the cheaper stuff like Rexons and they flex like crazy so you'll never get a square cut out of them. The price of a DW708 I'd seriously consider getting a RAS if I didn't need to be more mobile these days.....

Scrit

 

[devonwoody]

Matthew/Scrit,

I think even the blade flexes on this type of machine so if you paid £1000 for a SCMS the blade can still flex and then I suppose pull the cut off line?

 

[Freetochat]

I have an 8" SCMS from Rexon, and over the last four years it has more than paid for itself. I agree with what has been said, but these saws were intended for site type work and fulfill that job.

My understanding was that a RAS was difficult to maintain accuracy, and that was why SCMS gained favour in the workshop?

 

[engineer one]

i know that lasers started out as a marketing tool :lol:

but you do wonder why if the tool is not accurate, they
bothered to issue the first kinds of lasers with scms.

not sure that a dewalt or makita top of the line would have
too much flex in the blade when rotating.

paul :wink:

 

[devonwoody]

Paul the problem I see is that if you are cutting a 10x2" board and the blade starts to flex after the first 3" it is then steered across the remaining portion of board and does not follow the line.

 

[nickson71]

I've a cheapish SIP saw (approx £120) that I picked up a while back from ebay for use on the DIY front ....... stair hand rail and spindles, laminate floor, door frames etc

How I'm using it for wood work I'm now realising that I need to have a proper look at the angle settings and getting a better blade after this is done I'm sure that with a bit of care it should be accurate enough for my needs

I've given up on using the laser for the moment as it is not set right and the batteries are flat ...... again I'll be having a look at that too as it will help if set correctly

One thing that does frustrate me is the depth of cut when cutting wider boards for mitres ...... like skirting board ....... I end up trying to cut using the compound action and I've never been happy with the results

Maybe I'm missing a trick or I need a larger saw

 

[prawnking]

its been said to me time and time again buy the best you can afford,
i have taking a serious look at the elektra beckum (metabo) scms around £100 cheaper than any retailer @ transtools
click here
i have read a few reviews and they seem very good
click here for 1 of the reviews
i have a EB thicknesser very good clean finish, so if their scms are the same you should be pleased with one, but it all depends on your budget.

cheers

shaun

 

[engineer one]

woody
i kind of agree not least because when you start, you pull out
and push back in, so the solidity of the rails is the vital thing.

but i wonder whether often it is also that we are all trying to
cut too deeply at the first cut, and whether it might be safer and
more accurate to do two cuts. we do it with a router,
so why not a saw???

not sure it is the right answer, but certainly the rail flex is
a major problem with cheaper saws.

paul :wink:

 

[devonwoody]

Paul, sound a possibility, but I think I might grit my teeth or close my eyes, in case it started to ride up on that sort of operation on my SCMS.

 

[engineer one]

ok i agree BUT.

are we looking at this from the right angle. sorry

we tend to use the scsm in a very lazy way, because we tend to think
of it as a site saw, and maybe not that accurate, we tend also to
forget all the other things we ought to do.

first use a proper square to ensure that fence and blade are at the
correct angle to each other. start with 90 degrees, and then work back
from there.

second too many of us (including me )
do not use proper hold downs, just our hands, and obviously with a
long piece of wood, it will wave about. i have a proper ,well expensive
dewalt portable table with relatively decent stops and hold ups that slide along to give more support , but i rarely actually hold the wood down.

another thing i have recently seen which makes more sense
is to put two false fences, one against the back, and one at the bottom.
the back one reduces break out, and the lower one can add to the
width you can cut if you do not make it higher than the diameter of the
blade, as well as reduce break out. it might also make it easier
to stop climb out.
paul :wink:

 

[devonwoody]

Yes, it's back to that sophisticated carving again after cutting on the SCMS, block plane and shooting board. Plus all what you have said above.

 

[nickson71]

In terms of holding the work down I tend to use my hands also .......

However I'm in the process of setting up my workshop (just finished building it)

My plan for the SCMS is to have it on a moveable workstation that can slot into my main working area. The height of it will such that the bench either side and the work area of the SCMS will be at the same level. Thinking about it I may as well include some hold down on the bench

I'd like to do this setup with a home built router table, my sanding machine and grinder also another one with a plain table top

Must plan this out very carefully as my shed is only 2.3 x 2.5 M2

Ian

 

[matthew]

Thanks for all the replies on this, very interesting reading. I guess any accuracy issues can be dealt with by fettling - much more important to have something that's rigid and repeatable.

Sounds like there are some good sliding saws around - but I guess a fixed mitre saw would be more rigid? Enough so to sacrifice the length of cut? Food for thought...

 

[engineer one]

matt this comes back to the old question, what are you going to be
doing.

have to say where i to go backwards, and were it available then,
i would have seriously considered the eurekazone rail system
not least because it saves a bunch of space.

i wonder whether too many of us (like me ) worry about
the infrequent times when we will be cutting large bits of wood,
rather than what we do on a day to day basis.

i do wonder how many of us diy/low end users actually need
a mitre saw???? :?

paul :wink:

 

[Scrit]

I think even the blade flexes on this type of machine so if you paid £1000 for a SCMS the blade can still flex and then I suppose pull the cut off line?

Sadly true. The only thing you can do is go for a thicker blade, like the 3.2mm kerf blades sold for use on RASs rather than the ultra skinny types (2.2 to 2.5mm) sometimes sold for portable tools.

One thing that does frustrate me is the depth of cut when cutting wider boards for mitres ...... like skirting board ....... I end up trying to cut using the compound action and I've never been happy with the results

Maybe I'm missing a trick or I need a larger saw

Have you tried "bumping-up" the skirting on top of a piece of ply or MDF to "steal" a bit more on the saw diameter?

Sounds like there are some good sliding saws around - but I guess a fixed mitre saw would be more rigid? Enough so to sacrifice the length of cut? Food for thought...

A fixed chop saw will certainly flex less...... OK if you can love without a 10 or 12in crosscut (and I can - Bosch plunge saw and rail for that, although I suppose a Festool might do at a pinch :wink: )

Scrit

 

[matthew]

Thanks again for the interesting comments (is there no end to Scrit's knowledge of tools?)

i wonder whether too many of us (like me ) worry about the infrequent times when we will be cutting large bits of wood, rather than what we do on a day to day basis.

This is a very good point - it's easy (very easy unfortunately ) to get carried away with what tools we need! Obviously if you are a professional, then anything that saves you time is potentially worth buying. As a hobbyist, however, I've learnt that there are ways round most things without having lots of large tools.

Eg if I need to cut a bit of ply/MDF from sheet, I'm quite happy to cut it to within 1 or 2mm with a jigsaw and very quickly finish it off with my trusty Stanley no 7. Or when I've had to do longer timber crosscuts, I've again used the (overworked) jigsaw to within a couple of mm and then finished it with the router and a clamp guide.

That's why my first large tool purchase was a P/T, because getting square-edged timber from sawn is definitely something I can't find any other way round - and I'm finding getting really clean crosscuts to be another.

And now that I'm prompted to think about it (thanks, engineer one), I very rarely use the sliding mechanism of my SCMS so I might well be better off (not least financially) with a fixed saw.

i would have seriously considered the eurekazone rail system not least because it saves a bunch of space.

Yes, I was also impressed with Shady's review of this and it looks tempting. Still debating whether to get a circular saw and/or something to guide it, would definitely be useful (see above workarounds!). With a rail like this, what's the lower limit to the length of crosscuts you can safely make - looks like it might be a bit precarious on a small plank?

Come to think of it, what are folks' preferred methods of cutting narrower timbers eg table legs, rails etc? I would immediately think of the mitre saw - but again, likely because it's the only saw I have (And all this talk of dados has been scaring me off having a table saw!)

Regards, Matthew

 

[engineer one]

matthew, just used my mafell ksp40 which is a smallish
circular saw with a guide rail that rolls up so it fits in one of the
boxes for storage. unlike the festo, this one actually can be locked
in a plunge position, and the rail is 1220.although small bladed, it
will actually cut a 40mm worktop.

had some odd 12mm mdf to cut back to square for the backs
of my latest cabinets, too big for the table saw, so thought i'd try
as usual with us all, i was working in a silly small space, but good finish,
and quick after setting up, and it fits which is the most important
thing. were i looking again, might well consider it as the one and only

as for smallness, i think no less than 6 inches, and witha good support
at the other end.

paul :wink: