Smart and brown model L hardware

[AgnewBlues]

I have recently picked up this one and I am wondering what the bed mounting screws were. Does anybody know? I assumed it would’ve been Whitworth thread, but it is definitely not 12 TPI, although it appears to be half inch. It is either 13 TPI 1/2” UNC, or something similar. As I am in Europe, these are not available locally and I do not have any in stock of that size. The threads are quite worn so I’m having difficulty measuring accurately. Any help would be appreciated.

The idea is to restore the machine and modify it for a particular application. I have other lathes for normal work. It did not come with a bench or screws. It was set up with a lever operated compound and tail stock. I also have a normal tail stock and dead length collets and closer.

Is anybody here running a model L?


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[billmac]

I think that model was based very closely on a German design by Boley. It is just possible that there are 'unusual' threads because of that heritage.

Smart and Brown also adopted the South Bend design for their SAB models so they had a bit of a history of importing design ideas.

 

[rblalexander]

Everything on my 1024 is either BSF or BSW no UN threads at all, not much of a guide but might help.

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[billmac]

Surprisingly, my 1024 has at least one metric leadscrew and it is an Imperial version. Apparently the reason for this is the geared dual inch/metric dials.

 

[rblalexander]

Oh yep, the exception on my machine is all the feed screws and lead screw, all metric. Pity I don't get the nice inbuilt threading dial

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[AgnewBlues]

Thanks guys, the mention of metric got me thinking and I tried an M12 bolt I had laying around, 1.75 mm pitch, and this is the one! However, what I originally thought was worn out threads could have been a previous owner drilling and threading from something like 3/8 inch. It just didn’t occur to me to try a metric screw on a vintage English machine!

Although I do have an ancient Lorch lathe that has a random combination of metric and imperial threads!


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