Hardinge collets 5c with long nose - why?

I bought a small lot of 5C collets at auction recently because there were quite a few metrics in the lot. Also in the lot were (3) 5c collets with an extended nose. What might be a common usage for these - I have never seen such a collet before. The nose of the collet protrudes about 1.5 inches outward from spindle.

The image uploader on this forum is not working for me today. I will post w/o image and try to add images VIA editing the message or try posting from a different machine tonight.

Edit - no joy in uploading images in edit mode either. I can select them and when I hit the upload tab the images disappear.

There are a couple of possibilities, and we can be more specific after you add some photos.

If the long-nose collets have shallow recesses about 0.5" ID and tapering noses, they were probably used with the specialist Hardinge contact-lens turning setup. Contact lenses require very precise curvatures, and the long nose of the collet gets the work out to a convenient location for setting the "compound" center of rotation.

If the long-nose collets are basically solid bar (possibly not even slit), they are fixture collets, intended for machining an appropriate nest to locate a non-cylindrical part.

If the long-nose collets have a slotted head and provision for an expanding screw, they are ID collets (very often "emergency" to be machined to fit the job).

Those are not the only possibilities. Hardinge made three or four variations on 5C collets, including a couple of "dead length" systems for precise axial location.

I have some collets with a extended nose The extension has a radius These are for hobbing
To grip the workpiece closer to the hob

Peter

Hardinge 5c collets with long nose.

Peter from Holland said:

I have some collets with a extended nose The extension has a radius These are for hobbing
To grip the workpiece closer to the hob

Peter

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I used to often use extended emergency collets. Most times I used the shorter extended nose ones. They only stick out about 3/4 inch from the spindle. I held the heads of rod ends after boring dia of round and then milling angle of taper . Over the years we bought hundreds of the collets. We then drilled and bored thru head of rod ends and formed a radius for the ball to rotate in. Somewhere I have a pic of holding one where the length of rod end was about 4 inches long.
We also used them to fixture other odd ball shapes.

They extend parts in front of spindle.


Jimsehr

From Hardinge:

Extended nose collets are for the same application as regular 5C collets. The extended nose permits deeper counterbores and tool clearance for extended work. 5C extended nose collets have internal threads for Hardinge positive stops.

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https://www.shophardinge.com/productGrid.aspx?catID=7258

SeymourDumore said:

From Hardinge:




https://www.shophardinge.com/productGrid.aspx?catID=7258

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SeymourDumore: Thanks for the link. The standard Hardinge image in the link appears to be for 25+mm stock (even if I select the 2mm collet) but the configuration (3 slots & the .125 (guessing) holes in the slots is the same - just the nose it tapered, even on a collet for 3/4 in. stock.


BTW, is anyone else having issues uploading images? I can fetch the image off of the laptop, go get a second image but once I select the "upload" tab the image file name disappears and the image does not populate in the section below. At lunch today I was using a Win7 machine and now a Win10 so I doubt it is hwd/software related on my end.

Yes, the images are just a static, generic representation of the collets.
The smaller diameter ones do have a a considerable taper starting from just past the spindle nose.
The smaller the dia, the larger the incl. angle.

And they do come handy when clamping on thin walled tube as well.

They are for id gripping. Turn the od to the part id size and drill and tap for a tapered set screw.Tighten set screw and you have an expanding arbor for a collet lathe.

CORONA VIRUS said:

They are for id gripping. Turn the od to the part id size and drill and tap for a tapered set screw.Tighten set screw and you have an expanding arbor for a collet lathe.

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Wrong, they are extended nose OD-gripping collets