Re: Will a 9-A leadscrew work for a 9-C to 9-B conversion (no quickchange)?

Ondrej Krejci
 

Cutting the keyway with the lathe milling attachment will be a tad tedious.  A Miracle Point level would be handy.  Making the keyway slightly undersize and using a keyway file to bring in the fit and smooth the transitions would be the way to go.

Best of Luck

On Wednesday, April 1, 2020, 07:37:49 PM EDT, Harley Schlinger via groups.io <old1940@...> wrote:


I have cut many of keys with a milling attachment on a 10 inch Logan and now my 14inch South Bend over the past 50 years, Lathes were around many years before milling machines just look at the tooling that was made for the Old South Been Lathes say nothing about all the tooling that Machinist came up for a special item they were making, it’s all about Time and Ingenuity, Just rember the first lathe was not built on a lathe so don’t say it CAN’T BE DONE.

P.S.  You can keep Hammering Bamboo under your finger nails I don’t do pain,



On Wednesday, April 1, 2020, 12:08:13 PM PDT, Andrei <calciu1@...> wrote:


You cannot cut the keyway with the lathe attachment. Well, you probably could, but it would be easier to hammer bamboo sticks under your fingernails. 

Ideally, you would have a friend with a mill large enough to cut it in one pass, but if not, you could set it up and cut the keyway in sections. 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of Mark Moulding <mark@...>
Sent: Sunday, March 29, 2020 10:55 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Will a 9-A leadscrew work for a 9-C to 9-B conversion (no quickchange)?
 
My next question was going to be about how difficult it would be to cut that keyway.  I have a bench-top mill, and also the milling attachment for the South Bend (and I guess there'd be no problem running it without a lead screw for a while).

It seems to me that a huge amount of precision wouldn't be necessary, but it would be a whole new operation for me, and therefore a bit intimidating.  What would be the best way to hold the screw in a vise - rigidly, but without damage?  In fact, what would the whole procedure be?  (I got the "do it in sections" part.)  That screw is probably hardened, right?  So, carbide cutters? A milling saw if I can come up with one? Anyone know the dimensions of that keyway?

Or is this dicey enough that I should just wait until a 9B leadscrew surfaces on eBay?  (It's a 36" six-speed - the absolute cheapest model one could buy.  My dad bought it new...)

Thanks for the input - I really appreciate it!
~~

Mark Moulding
South Bend 9" Model C, Walker Turner drill press, Rong Fu table-top mill, "Mini" lathe, a whole bunch of Shopsmith gear

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