Slitting Saw Arbor. A useful workshop project

A recent enquiry regarding slitting saw holders prompted me to post my design for such a device. I developed this holder about 15 years ago, it works well and I have also made a couple that have been used successfully in a production environment. If you make this,you will have really useful bit of kit. It is self tightening but a key could be added if you had to reverse the cutter direction,(I never needed a key). I had drawings, but can't get them onto my new system so I offer photos and explanation as a substitute.

The main body diameter is 39mm. and the shank dia is 20mm. this is to accommodate the M10 x 85 cap-head screw that clamps the flanged nut from the back, enabling close proximity to the work-piece. The locating spigot is 25.35 dia x 1.5mm.with a minimal u/cut. Overall length of body 32.5mm and the shank length is 60mm. fFats are machined on the body (34 a/f)to assist with tightening. The body is bored to 19.05mm x 27.5 deep.

The flanged nut is 39mm dia.x 5.5mm thick and the body is turned to 19.00mm dia x 22 long. the flange is under cut 1.5mm deep.

The general concept can,of course,be modified to suit. Replacing with ​an M8 cap-head screw would enable a smaller dia shank, for instance.

Roy,

Nice job ... I made someting similar for my BCA, but with the shank the same shape as a collet.

BUT, to my shame; I forgot to include the spanner-flats

One day, the saw snatched & tightened the screw so hard that I had to drill the head off to release the tension.

... Lesson learned !!

MichaelG.

Very nice little project.

One thing you might want to do is make the shank a bit longer so that you have less difficulty trying to get at some work pieces with it. Most mills have a spindle quill, so it should make this less of a problem, if you did need to extend it over the top of a dividing head for e.g

Michael W

Edited By Michael-w on 16/01/2017 12:31:13

A short write up for MEW might be appreciated?

I like the relatively small nut, the much bigger one on my holder (to allow different bore sizes limits its use, yet all my slitting saws have 1" bores except two that are too small for the holder!

I would quite enjoy submitting a write up,I expect I will have to redo the drawings first.

Really constructive comments so far, and it was the shortcomings of what is commercially available, that drove me to make my own. Normally, I find, that 'universal' usually means 'compromised'.

This would be a good idea because the commercially available miniature arbours tend to be quite expensive.

Michael W

Hi,

As a newbie back in the 70's I finish machined my holder in a collet in my mill - when used it was still "eccentric" presumably because of the accuracy of the saw .

I also forgot the spanner flats!!

Tool

Starting with a morse taper blank is one easy mod to the project, I suppose? The shank size, above, would nicely suit an ER32 collet chuck, but the diameter would not be critical unless using a Clarkson type holder or morse taper collets.

The key would mostly prevent the over-tightening problem experinced by the odd user.

My 22mm arbor for the horizontal mill is based on an MT 2 blank arbor. It is surprising how easy it is to get cheap chinese involute cutters working more evenly, so there must be a bit of run out over the length of the arbor, but it has not bothered me yet.

My version of a slitting saw arbor is similar, but different!

Nigel Taylor 2. Great minds think alike! I can't understand why these are not available commercially, I have searched several trade catalogues over the years but never found anything similar. Roy M

Over the years I have made several but now I will make two more based on the designs by Roy and Nigel. Both have good ideas.

Quite like the simplicity of Nigel's version and might have a go at making one similar. Can I ask, assuming normal clockwise spindle rotation, does the nut have a tendency to undo? My mill has no reverse so I can only run it in one direction. Perhaps I should use a left hand thread and nut?

John

Both seem nice designs. I presume the clamping force for the saw must be as far outward as possible ? In the first design I see some recesses but not in the second. Is it flat?

I've not found a problem of the nut undoing, and, yes, the clamping face is flat.

When I got a set of slitting saws and an arbor, I found the arbor made positioning the workpiece awkward. I also thought it looked clumsy so I designed and made a low-profile version. My slitting saws are 5/8 inch internal diameter, so that is the size of the bottom portion. The flange is 7/8 inch diameter and 3/32 inch thick. The collar is bored out to 5/8 inch with a stepped diameter. The smaller end is a close fit over the thread. I choose to use a ½ inch UNF nut, partly because I liked the finer pitch compared to using M12 and also to try screwcutting an ‘imperial’ (American) thread on a metric lathe using just the standard changewheels. The shank is 10mm diameter, to suit an ER20 collet. This picture shows the arbor in use. When I made it, I slightly undercut the ‘corner’ by mistake, so I have to use a spacer when using very thin saws. However, my arbor design meant I could clamp the 12mm square piece directly to the mill table to cut the slit in it.

Thanks for the info Nigel, now on the list of projects, it has to be much better than the multi-diameter one I use at the moment.

John