ER32 Spin indexer - tightening and loosening the collet nut

I'd be grateful if any owners of the Stevenson's ER32 Spin Indexer could advise me of their technique for tightening and loosening the collet nut without the indexer's spindle [the silver coloured sleeve] rotating at the same time.

The thumb-wheel locking screw is not enough to stop unwanted rotation of the spindle when tightening and loosening the collet nut, and even a strap wrench has a hard job of stopping it from rotating completely.

Thank you.

I hold the handle at the opposite end with my right hand and nut spanner with my left.

The sleeve should be engaging with the pin just like an R8 collet so it does not rotate within the spindle

Thanks for the reply, Jason.

I don't really understand this.

The handle at the end is mounted via set screws on to a black sleeve that is free to rotate inside the outer sleeve/spindle. Holding this handle while tightening the collet nut just keeps the handle and black sleeve stationary while the outer sleeve remains free to rotate.

I had a problem with the handle carrier rotating on the sleeve. It was cured by making a hole in the sleeve for the end of a dog-point grub screw, rather than relying on friction.

I'm not sure this is your problem, but it helped me

Cheers, Tim

Bill, it sounds like you don't have the 5C-ER32 adaptor sleeve tight enough, put that in first and with top knurled screw locked and the index pin in a hole tighten the draw tube onto the adaptor sleeve by turning the handle, this will then lock drawtube and spindle together.

You can now just use the handle and nut spanner on the ER nut with the pin disengaged and the lock screw loose.

here you go Bill tightening and loosening the ER nut a couple of times and then removing the adaptor sleeve, you can see it toog quite an effort to undo as it needs to be tight otherwise the handle and drawtube will just undo. Those who have been using too much fairy liquid may want a soft mallet to pop the taper rather than the heal of your hand.

Thanks a lot for the help and especially the video, Jason; it's much appreciated.

Thanks also, Tim, for your suggestion. It sounds like it would provide a firmer hold between the handle and the adapter sleeve than just set screws on to smooth metal.

I've now tightened the adapter sleeve as tightly as I can following Jason's advice. I'm pleased to say after several tightenings and loosenings of the collet nut, the adapter sleeve is apparently still screwed all the way home and the handle is not wanting to unscrew it when I go to loosen the collet nut. Hopefully things will stay that way.

I found that the thin lock-ring at the base of the threaded section the collet nut screws on to had also worked loose. I'm not sure what the ideal tool is [some sort of thin-section pin spanner, presumably] for tightening this up. The blunt end of a 4mm transfer punch has had to do for now.

I've just discovered something that greatly helps me with tightening and loosening the collet nut: placing a block of wood between the flat edge of the handle and the milling table so that I don't have to hold the handle at all when tightening and loosening.

One last point: the c-spanner for the indexer collet nut is not a standard ER32 spanner because the nut diameter is bigger. If anyone knows whether there is a four pin spanner as well as the standard single pin one I'd be interested to know where to get one; I find four pin spanners way more secure in use than single pin ones.

Edited By Bill Phinn on 27/07/2020 19:57:08

Bill-talk to the lads at ArcEuro, they've got the 4 point spanners for both ER32 and ER40 listed.

Thanks for your message, Keith.

I wasn't very clear in my last message. The single-pin c-spanner supplied with the indexer is, afaik, a standard ER32 single-pin spanner. At any rate, the one I have fits both standard ER32 collet nuts [approx. 50mm diameter] and the indexer's 54mm diameter nut.

By contrast, the four-pin ER32 spanner I have, bought previously to fit my ER32 collet chuck nut, only fits the standard ER32 collet nut, not the bigger 54mm one on the indexer.

If there is a four pin spanner out there that fits the indexer's nut, I will gladly buy it. I'm almost certain that Arceurotrade don't sell such a spanner.

ETA: Is it possible that a four-pin ER40 spanner would fit the collet nut on the indexer? Since I don't own an ER40 collet chuck [or four-pin ER40 spanner], I'm not in a position to say.

Edited By Bill Phinn on 28/07/2020 00:03:12

I think an ER 40 would be too big at 63mm dia though as the indexer is for work holding it is unlikely to need the same holding force used on a hard cutter shank

Edited By JasonB on 28/07/2020 07:13:24

Is it possible that a four-pin ER40 spanner would fit the collet nut on the indexer?

Even more reason to ask Arc, as they stock both items?

Thanks for the further replies.

I think I can happily live without the four-pin version after all. The block of wood acting as a stop for the handle gives me much better control over the single-pin version than I have when using one on a collet chuck in the spindle of my mill.

did anyone mention a ball bearing nut?

No because the Spin indexer is an odd size nut and has a different thread to any other ER items unless you are up for making your own. Even then the larger size if the bearing nut would make it harder to get in close when milling with small cutters, hard enough with the supplied one.