Re: step collet - 3c
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Hardinge 5DS collets can be found in used lots at decent prices. They have an outer sleeve that has the 5C shape. The inner part is available in a collet style or pot chuck style. They're machinable steel with three 1/8" pins like 'emergency' collets. There's also an adjustable depth stop that screws into the parts to hold them together
Used lots will most often have all the collets drilled and bored to various sizes. Choose one cut smaller than you need, insert pins then bore out farther. Just think of it as someone else having already done the bulk of the cutting for you. :)
If you absolutely need an uncut one, Hardinge still makes all the 5DS parts.
On Tuesday, November 28, 2017, 7:16:40 AM MST, vtsblogan@... [SOUTHBENDLATHE] wrote:
That's a "step collet". The portion in front is for manufacturing, not part of the finished collet. These collets are meant to hold larger diameter, SHALLOW parts, like turning the face of a gear. You can do the initial machining with or without the stub in place. I can explain further if needed.
It sounds as if you really want a "pot" collet. They were made in 3C but good luck finding them. If you have damaged or cheap Chinese 3c's you can make pot collets relatively easily if you can get access to a mig type welder. I've made some dedicated size deep pot collets (6K though) to fit some parts I manufacture. 1" would be pushing it in 3C.
Using damaged collets it probably took about an hour to make the collets up.
You can of course make an entire collet from scratch, but it's going to take a lot longer, and won't be as durable.
At some point with a S.B. you have to ask yourself at what point you should invest in a 5C setup.
Let me know if you need more info.