Hi all. Is the 'Sliding Carriage' on a table saw what I think it is? i.e The table can be moved independant of the blade for short cross cuts. And therefore essential for accurate cross cut work requirements?
Arthur
Usually just a section to the left of the blade will move on linear roller bearings. This, as you say, is used for cross cuts. They also usually have a mitre fence that allows 90 and other angle cross cuts.
For accurate 90 deg crosscuts, especially on sheet material, a sliding carriage can easily be made to run in the mitre track. The engineered sliding carriage is a 'nice to have' thing.
I have an engineered sliding carriage on my saw, but still prefer my shop-built (American for Home-Made) one for 90's - it's more accurate since it's a fixed angle. Of course a proper sliding panel saw would be ideal, but expensive and even more space...
R.
Pretty much agree with the previous post - proper sliding tables are useful for heavier timbers though. Overall a mitre saw is often a better choice - if the work will fit a mitre saw (c. 300mm crosscuts for a mitre saw, 600mm for a sliding table - much longer for proper panel saws). Then again, for panels a guide clamped to it (I must buy one of the nice guide systems available now) and a handheld circular saw is a good solution.
Thanks. The work I'm preparing for is cross cutting 60mm x 70mm mahogany door frame timber.
Arthur
With that in mind, you might be better spending the price difference for a sliding table on a nice mitre saw instead.
never considered a mitre saw. Thought all they can do is chop-saw.
Just done a quick search and found this. Seems suspiciously cheap to me.
Arthur
A mitre saw will need a sliding table to cut timber for a cross halving joint. Can they do this?
Arthur
Or a pullover chop saw
It will for this particular job (i.e. 60 x 70mm), but because it is a mitre saw and not a *sliding* mitre saw its capacity for bigger stuff is limited.
The differences between types is explained here:
The better sliding ones can - they have an adjustable stop to limit the depth of cut.
here:
I'm thinkin..trench cuts.. are for grooves in framework timbers for panelling in wardrobe doors for instance?
Is that correct?
Arthur
Any non through cut really (although on a sliding mitre saw you are limited in length of cut of 300mm or so).
A mitre saw has one type of movement - rotation round a fixed point. Hence any cut it makes will have a leading profile the same shape as the blade. So not much use making for non through cuts. The sliding ones have this motion and a sliding one. So by rotating the cutting head to a set depth, and then traversing the work you get a fixed depth and flat bottomed partial cut.
This is a very quick way to cut notches, half lap joints, shoulders for tenons etc. You make a careful cut or two at the edges, then a number of closely spaced cuts in the waste section. The waste can then be knocked out easily leaving your notch etc.
A trench cut is any kind of "not-right-through" cut.
Two common situations where they're used:
Along the grain to make up something like a rebated profile (e.g. an exterior door frame)
Across the grain to make up something like a housing (e.g. for shelves)
The first you might do either on a table saw (with crown guard and riving knife removed) or with a router (neat but slow).
The second you might do with a compound mitre saw with depth stop or with a router (neat but slow again).
(A joinery workshop would probably use a spindle moulder (a superduper router) for both - but few diy'ers own them).
Not the Bosch one that you illustrated. That is intended for cutting completely through the material. If you think about the geometry, a simple mitre saw could at best cut a segment from a circle, so even if you slide the material sideways as a succession of cuts are made, you will end up with a curve at the bottom and not the flat that you need.
In order to do a flat bottomed cut on a mitre type of saw, it does need to have a front to back slider (i.e. SCMS) and some means to set a depth of cut stop in order to provide a consistent depth as you cut with a series of cuts moving the material as you go. Not all SCMS have a depth stop facility. I have a Makita LS1013 which does have this facility, but most do not. You can see that SCMS are typically three times the price of the simple chop saw. Unfortunately the cheap ones don't have the smoothness of mechanism and consistency for the kind of cutting being suggested here.
I have cut halving joints on this set up and it does work but is time consuming. Moreover, one has to be quite careful to achieve consistency. If you are making hardwood door frames, both the width and the depth need to be very accurate as does squareness and above all consistent.
Typically, I might make one or two joints for a relatively uncritical application in this way, but for making decent door frames, I would use my combination machine in one of several different ways depending on the application and the number of items being made. This machine has a sliding table to the left of the saw blade and spindle moulder. Material can either be clamped to it and run over or past the appropriate cutter or blade, and/or a cross cut fence can be fitted. The cross cut fence can be fitted with one or more sliding stops so that the length of material can be registered precisely.
For a shorter run, I usually set up the dado tooling in the saw. This replaces the normal saw blade and can be adjusted to provide a cutting width of up to about 22mm. I can then run the material through in perhaps 4-5 passes, starting with the material against the stop and then sliding it a little as I go until the end of the material is reached. I will probably use a number of depth settings as well so that a neater cut is obtained. Of course, all the pieces are run through and then the depth is altered. This also allows me to sneek up on precisely the correct blade height to get joint halves that fit exactly. The approach is relatively quick to set up but running the material through involves several steps.
For a longer run, I set up tenoning, rebating or slotting tooling on the spindle moulder depending on the joint type. This is more time consuming than the dado method to set up, but is quicker to run the pieces. There's a video at
Unfortunately, this kind of machinery is in the four figure range......
Usually it's used for _long_ cross cuts(sic), such as breaking down large plywood panels. The advantage of a sliding table is that it supports big, awkward and heavy panels.
It's certainly not essential, becuase there's a cheap home-made alternative for short cross-cuts, the cross-cut box.
Read Ian Kirby's highly recommended "The Accurate Table Saw" for details. It's an open-ended box that slides on top of the saw's table. There are walls fromt and back to guide the timber and a slot across the base to allow the blade to pass up inside the box. Sides are higher than the blade (so it doesn't fall in halves!) and there's a strip across the top as a blade guard. There are also closed boxes front and back, beyond the sides, so that teh blade is never exposed.
Quick, accurate, and saves your fingers.
Personally I regard cross cut sleds (like a box, but just a base with low sides and no top) to be too dangerous to use. For the trivial extra effort, make a box.
Agreed. The only thing is that some of the portable table saws don't have very substantial mitre slots (i.e. smaller than the standard U.S.
9.5 x 19mm slots) and there is the risk of anything running in them popping out in use... or were you thinking of a jig run against the rip fence in some way?
I don't think this is a significant problem. What would worry me instead would be saws with only a single slot. You don't need a huge slot here, but you do need widely spaced ones, on either side of the blade. I wouldn't make or use a box that was only guided by one slot - too much risk of twisitng and binding.
Slots aren't reliably a standard size anyway. It's important to make your runners fit _your_ slots. I've got three "saws with tables" here, two of them modern, and although they're all approximately the same size, I certainly can't swaps jigs between them.
I also keep a large supply of pre-dimensioned and carefully finished slot-guide stock sitting ready and waiting. I can make MDF jigs for anything in only a couple of careless minutes now, which encourages me to actually do it!
I certainly wouldn't do that, because of the obvious problem of offcuts needing to overhang the ends of the box, and less obviously because of the risk of kickbacks.
I thought dado blades were verboten in Europe and by law modern saws have arbours too short to take them. Or is yours an old saw that predates the regs?
Peter
OK, now I see what you're suggesting and that does make sense. With two slots, quite respectable support, although I suppose it does require careful tuning to get the runners perfectly parallel and free sliding....?
Quite.
Yes, I have a couple of Incra and Osborne fences that I use with the portable table saw. That one is of the nominal size but there are various mechanisms like grub screws and slots in the fence runner to adjust it for correct movement without slop.
Good idea. I've used some UHMW polyethylene bar for this which seems to work pretty well and is a touch slippery which helps.
Good. I would have been concerned. I tend to use the rip fence as little as possible anyway, apart from for cutting certain sized pieces where the slider isn't suitable. Using the slider does at least also mean that one tends to stand to the side which is also a good thing
Yes and no. There is much folklore on the subject which is covered in the Machinery Directive. The supporting standards of course are not freely available. The situation is actually as follows:
- There is a difference between whether the machine is used in a workplace vs. being used personally - i.e. whether H&S legislation applies.
- There is a difference between whether a machine is imported for personal use or to be sold (aka Placed on the market). Therefore you won't find saws equipped for stacked dado cutters legally on commercial sale in Europe, and yes you are right, the arbor is made shorter as well, although this has to do with product liability and not legislation AIUI.
- It isn't in any case illegal to buy and use stacked dado tooling in Europe - that is still perfectly allowable on a radial arm saw. Why escapes me because I think that they are more dangerous than table saws but there you go.
- I can perfectly legally, and have, bought a saw with long arbor in the U.S. and have personally imported it and can use it. However, I couldnt use it in a place of work or place it obn the market.
- The actual requirement with fixed machinery is that it must be possible to stop the tooling within 10 seconds. On the American type of table saw, with a full stack of dado blade running at full speed, it isn't possible to achieve this because of the mass of the rotating tooling.
On my machine, both on the saw and on the spindle (actually on all motors) there is an electronic VFD which generates three phase for the motors from single phase and does speed control and electronic braking into the bargain. There is then tooling which will go on either the saw or the spindle for dado cutting. It consists of two steel components which are shaped like bow ties with curved ends and which fit together to form a disk. On the edges are replacable tip cutters (ends and sides). The two components fit together but can be shimmed apart to make a variation in width as required in steps of 0.05mm. So it becomes simply a case of fit, count the shims and measure the cut.
In operation, the electronic braking will stop the tooling comfortably in under 10 seconds - actually on the larger dado tool set, it's about
3 seconds. So perfectly legal.HomeOwnersHub website 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.