Stevenson's 5C spin indexer

I've got one from J&L that looks the same but without the ER adapter and the base is about 4.25" wide (perpendicular to the axis) and 4" long. Slightly narrower now that I've milled the sides parallel to the spin axis to allow it to be quickly aligned with the T slots, it came unmachined on those faces, but it was much cheaper than the Suburban tool offering.

looks

I had assumed the sides would have been cut parallel with the spin axis already!

How did you get it aligned with the axis for milling? Just turn it upside down?

My vice will hold up to 3" wide, so it would be good if I could cut the base down to that to allow it to be held in the vice, which would make for quick and easy deployment!

Brendan

Is John S the Stevenson of "Stevenson's 5C spin indexer" or is that just coincidence?

I like the idea of being able to use ER32 collets ...

Brendan

It is not a coincidence - the same Stevenson.

Regards, Tony

Not in the case of the one I bought but it was like £35.

It has been a few years but IIRC it was clamped to an angle plate through the bore and the base clocked level side to side (the base was ground), the angle plate being set square to the mill, and the sides machined. Just having looked again the index plate face end shows the machining marks spiral outwards indicating it has been faced and I assumed the bore done at the same or the face used as a reference, subsequent checking of the accuracy shows the machined sides to be square to closer than anything I need to do. Interestingly the collet closer end appears to have been machined on a shaper as the tool marks are parallel.

Looks like you could machine it down to 3" wide. I always fit it straight to the mill table and align it to a T slot but the table is 9" wide.

Then why didn't he ensure it was designed and manufactured with the sides machined parallel to the spin axis?

gd&r :)

The only use for that would be when cutting splines or key seats.

For all other uses, the fact that the base is parallel to the axis is sufficient.

Mark Rand RTFM

It was John's idea, but that doesn't mean he has any control over the manufacturing process.

Regards, Tony

A good question to which I don't have an answer.

John S.

I was taught that tools of this sort, dividing heads etc, normally have a reference face parallel to the axis to allow quick alignment against a block in the T slots. Certainly works for me for what I normally do where you want the axis set parallel to the table axis. On the odd occasion I have milled tapers having placed a taper block between the T slot block and base, it's a useful time saving feature.

BTW I didn't know that John Stevenson indexer was not machined on the side, I noted in my original post that I had sourced mine from J&L and their cheapo one wasn't machined on the sides.

I assume, then, that the intended method is to use the workpiece as a means of clocking the indexer to the table axis?

Obviously this can be done, but not nearly as convenient as having a machined side to reference off! If the thing comes to pieces then I guess yet another project will be to mill the sides square to the axis somehow! And make the base smaller.

It might even be nice to make a plate with holes for just four and six-sided cutting - there are an awful lot of holes to go wrong with on the supplied plate! Not entirely sure how I could do this mind you ... ;)

Brendan

One way to do it but the item I thinks it's a knock off of here,

It does come to pieces quite easily, at least the one from J&L.

Can't see there would be much point in going to the trouble, although the disc on mine is held in place by a threaded ring so would be easy to change. The plate is numbered 0 - 35 (36 holes) and the vernier pin holes 0 - 9, and there is a pointer mark between 4 and 5. If you leave the pin in hole 0 and have the pointer on 0 on the disc at the start then 4 sides would be disc holes 0, 9, 18, 27. 6 holes would be disc holes 0, 6, 12, 18, 24, 30.

Bugger! I was expecting a really witty reply (or a profanity)

If arc euro are at Harrogate this year I'll probably buy one though, looks a useful bit of kit.

Surely if you were cutting say a hex on a round bar the transition radius from the hex to the round wouldn't be perpendicular to the axis?

Getting a nice consistent radius in this area might not matter in all apps but it still looks messy if things are not squared up.

Yes, you're right, I really shouldn't start trying to "mend" it until I've got one and can see if it's "broken" or not!

Brendan

Sorry to disappoint you, now piss off.

John S.

squares and

Well, I can now answer my own question. On the one I got from AET, the base is about 100mm long and 114-116mm in width. Distinctly trapezoidal in fact! It'll need a little milling before I can use the sides for quick alignment.

Brendan

If it's to hand Brendan, can you tell me whether it will pass 19mm bar completely through the head when in ER32 mode ?

Thanks,