Centre drilling long length, small diameter bar

[Andrew TinsleyParticipant @andrewtinsley63637]

I had the same problem with a 2metre length of 16mm threaded rod. I needed to turn down both ends. I simply put the length into the chuck by pushing it through the mandrel and thence into the chuck. My pal did the turning and I simply put a metre length of cheap 30mm plumbing plastic tube over the free end.

I thought this might be a bit dangerous, but in fact it was a total non event. The tube held the threaded rod and I held onto the tube. Easy!

Andrew.

[John McNamaraParticipant @johnmcnamara74883]

A few thoughts…..

When I bought my lathe it must have been used for Long bar work, There was an expanding plug in the outside end of the mandrel, quite nicely made actually, it could be expanded to lock it in place, in the centre was a bored hole to fit the bar to reduce the bar whipping out of balance.

To centre drill a thin rod you could hole it in the fixed steady and then drill form the tail stock as usual?

Automatic lathes with bar feeders sometimes have a wood lined long thin box to hold the several metres of rod sticking out the back end of the lathe, The wood to reduce the noise, This method would require careful design, if the bar got out and started flaying around it would be a disaster.

Regards
john

[larry PhelanParticipant @larryphelan54019]

Hi Dave,

I,d have to go along with you there,but then, I,m also a cowardly lion [or cub ]

Nothing like a 4 ft length of bar whipping around the place to liven things up !

[egaParticipant @ega]

Bill Wood 2:

"What is JAR's name and what is the book called please ?"

Sorry if I assumed too much.

JAR is/was the late Jack Radford, a frequent albeit under-appreciated contributor to ME (Model Engineer). His book, Improvements and Accessories for your Lathe (TEE Publishing 1998) is a compilation of his c 1970s articles based on the Super 7 lathe. Much has changed since then but the book is still worth reading (or turn up the articles if available).

The relevant article is Stop Bars and Bushes for Lathe Mandrels.

OT: I sometimes wonder whether an in-forum glossary of accepted abbreviations would be helpful; I am still trying to fathom Neil's "PLA" – one of the most common TLAs but not the Port of London Authority!

Edited By ega on 08/08/2017 14:30:59

[David Standing 1Participant @davidstanding1]

Posted by ega on 08/08/2017 14:30:13:

OT: I sometimes wonder whether an in-forum glossary of accepted abbreviations would be helpful; I am still trying to fathom Neil's "PLA" – one of the most common TLAs but not the Port of London Authority!

PolyLactic Acid

[egaParticipant @ega]

Posted by David Standing 1 on 08/08/2017 15:01:04:

PolyLactic Acid

Thank you. I see they are now 3D printing brain cells!

[David Standing 1Participant @davidstanding1]

Posted by ega on 08/08/2017 15:05:58:

Posted by David Standing 1 on 08/08/2017 15:01:04:

PolyLactic Acid

Thank you. I see they are now 3D printing brain cells!

The mind boggles………

[MeunierParticipant @meunier]

Posted by David Standing 1 on 08/08/2017 15:36:15:

Posted by ega on 08/08/2017 15:05:58:

Posted by David Standing 1 on 08/08/2017 15:01:04:

PolyLactic Acid

Thank you. I see they are now 3D printing brain cells!

The mind boggles………

Or it will do when they are installed…..

[Author]

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