I was lucky enough to be given a lot of tooling and some machinery from a friend's estate. Amongst the hoard was a brand new 5C spin indexer, of the Chinese variety, with a small selection of collets.
Whilst looking around for a matching tailstock, I came upon the Stevenson 5C Indexer which also takes ER32 collets. This set me thinking
The Stevenson uses an oversized collet closer nut and the threaded portion of the indexer spindle, which is usually machined parallel, has the thread right to the end. I believe it then uses a special sleeve to fit inside the spindle.
After several mental iterations of how I was going to achieve a modification so that mine was AC/DC, so to speak, I picked up a piece of "scrap." It was an ER adaptor that I had made two or three years previously, to fit the quill on my Progress 2 to allow me to mill. It worked but was not entirely successful since there was too much run out. It was relegated to a space on the bench, where it got buried. It surfaced during a tidy up and seemed to be the obvious starting point since it saved me having to machine the taper and thread cut again.
I did a Millyard on it. Think about it, visualise how it's going to look, and do it. No need for anything other than a few measurements to ensure everything was more or less feasible. Drawings are for amateurs, aren't they?
First off I set the compound for 10°
I then chucked it on the lathe between centres, mounted on a piece of 20mm silver steel, and set to.
Christ knows what the steel is, but it was damned tough (like every piece of odd stock that I've collected over the years).
After quite some time with stops for coffee, thought, and the odd measurement, it became this.
Having a root around in the scrap box I turned up a piece of 1" gas nipple. Just right methinks. Note: It's in the vice because an elbow that was screwed on did not want to come off again. The huge shifter soon persuaded it otherwise
It's a little light of material in places but I thought there'd be enough steel for it to work (see later image of the keyway). I rough turned the OD and bored the ID to size for the spigot on the rear of the chuck head.
Out came the silver soldering kit and I glued it together
Back into the lathe and it's time for finish turning of all surfaces, cutting the thread, and milling the locating slot.
The finished beast. I'm pretty happy with the outcome, since it's used scrap, a little MAPP gas, and an inch or two of silver solder (electricity costs notwithstanding)
Yes, the keyway just broke through, but I can't see that that will be a problem. Anyway, here it is installed
I have used it a total of once, so far, to make a 30 tooth gear for a Raglan lathe, but I'm sure it'll pay for itself in the long run