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Trying to identify some 8mm ring and step collets...

nw10
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nw10 New Member

nw10

Posted
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Hi,
I bought a Boley 8mm lathe on eBay which came with some ring and step collets but unfortunately they don't fit the lathe. Judging from appearance they may be from 2 different manufacturers. They don't have a makers name and I hope they will look familiar to someone?
Thank you.

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LittleWatchShop Distinguished Member

LittleWatchShop

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Posted (edited)

How is that they do not fit?  Do they not fit at all into the spindle?  Do they fit in the spindle, but only so far?  Do they fit all the way into the spindle but do not interface with the draw bar?  Do the threads fit the draw bar when outside of the spindle? Can you show a measurement of the diameter of the collet?  Is there a key in the spindle but it is too wide for the key clot?  Have you fit a standard collet into the spindle?

My computer does not work.  What is wrong?

Edited by LittleWatchShop
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HectorLooi Distinguished Member

HectorLooi

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I've come across a few ways that a collet might not fit.

The collet might be the "long" type, where after tightening the drawbar all the way, it's still loose. This can be solved by putting washers on the drawbar until the collet can be tightened.

Another way is the collet is too short that the drawbar cannot engage the threads. It might be possible to lengthen the drawbar or buy a longer drawbar.

Thirdly, the threads might not fit. I'm aware that China made lathes use a different thread pitch for their lathes. Although it's also 8mm, they won't fit a WW 8mm lathe. I'm not sure if buying a China made drawbar will solve this problem.

Good luck!

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nw10 New Member

nw10

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Thanks both.

One of the step collets is just too big to fit into the headstock. It measures 7.8mm diameter at the level where the slot starts compared to 7.75mm at the same place for the Boley.    

The other 2 step collets fit into the headstock but the drawbar / spindle only will only tighten half to one turn. The screw gauge on both collets is 40 Whitworth (same as a Boley collet). But the external diameter at the threads is 6.99mm compared to 6.83 of the Boley.

Maybe a Chinese drawbar would work. I tried looking on ebay but could not find one...

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