5C collet chuck with integral DI-3 backplate,anyone bought one?

[Diy AddictParticipant @diyaddict]

I'd be interested to see how you get on. On mine, doing a one-off adjustment with gentle taps, it was perfectly true. But when I took it off, then put it on again, it was no longer accurate. I think this was due to my Myford 254s not having a 'proper' D1-3 system. You just replace the cam studs with threaded ones, then it fits to the spindle with three nuts. I found that tightening the nuts affected the accuracy – some kind of flex happening somewhere. Hence I went ahead with the grub screws.

Assuming you have a proper D1-3, presumably the tightening will be more consistent and you'll get better accuracy just after one initial setup.

Paul

[Neil LickfoldParticipant @neillickfold44316]

I am going to be putting mine onto a S7, so no D1-3. For me, the issue is with the lower spec collets that I do have. Some are better than 0.01 while others are around 0.05 tir error, when tested on a Hardinge lathe. The emergency collets will be fine, they have the pins to close the collet with and then just bore out to suite. On the ones that are a long way out, I may set them up and then regrind them true again. This will have the added advantage of putting spring into the collet like a Hardinge collet is. Instead of being basically sized and causing scratches on soft parts.

My adapter will be used for second ops of parts that need a higher level of precision that I can get easily with other means. I like the use of the plates that allows parts to be the same height under a shoulder, like for making sleeves with the same flange thickness, or for making the second side with a simple detail to being concentric with the first side. Like the glow heads of engines where the clamp ring is screwed into the case instead of the series of screws holding it all down.

My other thought is to make the backplate that goes onto the S7 spindle, have 4 temporary outer clamps, that can be used as a means of micro shifting the body around the backplate , then tightening the screws in place. Remove those 4 clamps and use away, until it requires an adjustment again.

Neil

[Diy AddictParticipant @diyaddict]

Oops, yes you did originally say you had an S7 and a Chinese lathe – I'd forgotten.

I must say I've really enjoyed using 5C collets, now that I have most of the common sizes. I started out with ER collets, then Burnerd Multi size, but I often work with quite stubby pieces that are too short to go in them. The 5C works great and has plenty of grip without having to be excessively tightened.

Looking forward to seeing what you come up with.

Paul

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