I need to buy a Slitting Saw

[Oompa LumpaParticipant @oompalumpa34302]

No doubt all of the various factions will argue for and against (and that is fine by me) but I need to buy a slitting saw. I don't have one or any other method of slitting a bush so it's time to "invest" in more tooling. I need a MT3 arbour and that's the first question, which one? I have seen both a 'Screw Type' and 'Nut Type' milling arbour for sale on this page -> **LINK**

and as I don't have anything like this and I would like to buy only one this month which one should I be buying?

[Oompa LumpaParticipant @oompalumpa34302]

[Clive HartlandParticipant @clivehartland94829]

To Oompa Lumpa, A name would be nice. Firstly decide what the Arbor diameter should be, Inch or metric, look at the listings and then decide. This will determine the size of the slitting saw center hole and somewhat the outer diameter. Then decide what thickness of slitting saw you want, nominally say a:- 1.5mm or 1/16". for slitting bushes, thinner for smaller dia. bushes. So, again the dia. of the bush will dictate the size of the stem of the Arbor and also the choice of the saw blade and its Dia.

In MT3 you have a wide choice of stem diameters and length of Arbors. If you work close to the Vice then a shorter Arbor is OK .

Slitting saws are obtainable in sets and also on Ebay where you might bag a bargain. Slitting saws can come with fine teeth or coarse teeth, again make a choice for the materiel being cut. do not run the saws at high speed, slowly and gently is the way because if you get them hot they will distort, so you need to apply constant coolant.

Personally I bought both an Inch and a metric arbor in MT3 in the sizes 1" and 22 mm stem. This gave me a wide choice of saw dia. and thicknesses. It is surprising that a 110 mm saw close to the vice will be quite limited in depth of cut. Other Forum members will have different ideas and suggestions.

Clive

[Clive FosterParticipant @clivefoster55965]

In general nut type arbors are longer than screw type ones so you can get the cutter further away from the end of the mill spindle / quill / head. Conversely that means you have more sticking out below the saw with the nut type if you adjust the spacers so the saw is up towards the mount end. It is said that the screw type does not support the saw as well as the nut type so long versions are impractical. Whether that particular difference is important on typical Model Engineers machines which are small and less than stiff by industrial standards is another matter.

Fundamentally its a matter of work size, machine size, machine speed and machine power as to which style is most appropiate for you. Probably good to do some sketches or rough CAD to help visualise where things are in relation to each other and how much daylight / travel you have. Although a larger saw may appear to make things easy in some respects they have to be run at correspondingly lower speeds which many Model Engineers machines don't have.

Sitting saws are scary things to use. Make sure you have guards and a "do not disturb, I mean really really do not disturb", sign on the door. Your brain is attuned to normal cutters, pretty skinny things, not sharp stuff sticking out sideways quite a way!

Clive

[VersabossParticipant @versaboss]

Clive said all and more what I also would have said (maybe using less words ) But one thing I want to add nonetheless.

The 'nut type' can be used in a horizontal mill (or with tailstock support in the lathe), because they (should) have a center on the free end. The 'screw type' surely will miss this center!

Greetings, Hansrudolf

[JasonBModerator @jasonb]

Or just use a hand saw to split the bush and machine the two faces flat before sweating together.

Be aware that thin slitting saws can wander in bronze bushes.

Screw type works for me, also allows you to get closer to the vice if holding work that way..

Edited By JasonB on 20/10/2013 07:40:58

[Oompa LumpaParticipant @oompalumpa34302]

Thanks everyone for your comments.

So really, just buy the one that suits the job at hand and go from there! That's okay, I will buy the 22mm dia. shank and a 1.5 and 0.6mm saws as that will do the job at hand, nut shank as the job will be vice held.

There is no doubt whatsoever that I will need to buy a completely different setup for the next job, it's the nature of things Interesting that the saw may wander in bronze, I take it this also applies to brass?

[Oompa LumpaParticipant @oompalumpa34302]

Should say 0.8mm (oops!)

graham.

[JasonBModerator @jasonb]

Graham if the work is stood vertically in the vice and the mill spindle vertical then the screw type will allow less sticking out, I use the type with a CSK screw which is not shown in teh link you posted.

Or you can get stepped ones that will take a range of saw bores.

And yes I know what you are all going to say, I've just been down and mocked it up for the photo

Edited By JasonB on 20/10/2013 09:22:13

[Sub MandrelParticipant @submandrel]

I have the stepped type of holder as in Jason's picture. With a parallel shank it has to go in a collet holder and the thick washer is a pain. I keep meaning to make a new plain holder with a much thinner washer from an MT3 blank arbor, as all my slitting saws have the same size hole,..

Neil

[Russell EberhardtParticipant @russelleberhardt48058]

Whatever you do don't buy the stepped type. I made that mistake and the saws would only cut on two or three teeth it was so badly made. I now use one identical to that pictured in Jason's post for 1" saws and a couple of homemade ones for odd sizes.

Russell.

[Peter TuckerParticipant @petertucker86088]

Hi Oompa Lumpa,

I make my own arbours, if you did the same you could buy something else.

Peter.

[WALLACEParticipant @wallace]

A smidgeon off topic perhaps, but how much axial run out would you expect to see on, say a 3”slitting saw ? I presume the saw blanks are ground flat to a high precision and the arbour is the fly in the oitnment when it comes to wobble !

W.

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