In article , Fred wrote:

I need to build an automatic machine to perform a fairly simple job.
I'd like to use a small lathe, possibly a SB heavy 10, as the basis for
the machine as they are fairly easy to find and inexpensive. This will
be a dedicated machine that won't be used for anything else, thus it
doesn't need screw cutting capability or power feeds. However, I've run
into one problem right away that has me scratching my head for a solution.

The job:

12" long x 1.25" diameter bars of a plastic material need to be cut into
2" long sections withe a hole center drilled their entire length.

The problem:

With smaller diameter stock, say 1", I would feed the stock through the
lathe spindle, holding it with a collet. Drill 2" in using the tail
stock and then part the 2" drilled section off. Feed the bar over 2"
and repeat.

The problem is 1.25" stock won't fit in a 5C collet, it needs something
larger (2J?). What small lathes out there have larger spindle
capacity? Most of the lathes set for 5C collets have 1-3/8" spindles,
or possibly 1-1/2" spindles, neither of which will accept larger
collets. I guess with a 1.5" spindle bore I could fabricate a custom
collet that would hold the 1.25" stock, but I don't know if this is the
best (only?) way to go. Opinions and ideas on how to approach this
would be appreciated.

Thanks!

You don't have to have a collet, you can just grind out a 3-jaw chuck to
a good fit on 1.25" stock anmd you are only limited by the spindle hole.
Since you are making short pieces you might look at some 3-in-one
imports; you don't need the mill part but the rest might be the right
size for what you want.

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