Cutting long acme threads?

[ibewgypsie]

I have been searching for "the" proper way to cut long acme threads.

I am tempted to cut a die to go into a adjustable universal pipe die.. I got 4 cutters in it to mess up.. Get fixated on a 10tpi? if I do?

Research says a moving follower like a stead rest, except it bolts to the carriage..

ANY CLUES? how do you do it, have done it?



------------------
David Cofer, Of:
Tunnel Hill, North Georgia

[hoffman]

We used to make our own leadscrews at a shop I worked at. I think they were 5/8 not sure of the pitch. We had a home made follower rest that bolted to the carriage. I never ran that particular job but I think it had several support places on the steady to keep the stock from "climbing" over the tool. The guy who ran that job just used a tuna can/brush for coolant. Believe it or not we made tire lathes...

http://www.amermac.com/1200r.html

------------------
Hoffman in Warner Robins Ga

[This message has been edited by hoffman (edited 11-14-2004).]

[aboard_epsilon]

Put in the make of your lathe into ebay and do a search on "traveling steady".
thought every lathe had one as a optional extra.
so there should be one for your lathe.
Alistair has a pic of one in his photobucket files .
ask and he will relay the picture here.
they look like a "c" with two points of contact.
all the best...mark

[j king]

David,It is probably cheaper to purchase a piece.We buy anywhere from 8 to 20 ft screws and turn ends down to suit.These are rolled and I believe they are probably better than you can make unless you spend alot of time polishing.Need to figure what your time is worth.We buy Keystone.I dont know how long you are talking .
Jim

[This message has been edited by j king (edited 11-14-2004).]

[wierdscience]

You can get 3&6 foot lengths from MSC,I believe it is Keystone brand as well.

You can also get odd pitches,even lefthand from McMaster-Carr,but they cost more.

To answer your question,yes I have done it on some lefthand stuff I couldn't get.It requires a follow rest and lots of patience as it is a PITA.

[Forrest Addy]

You cen get Acme screw sstock or threaded blanks to order from Nook Industries.

Long lead screws are made with follow rests or bushing plates. It's difficult to support the work as the tool moves from one end of a long skinny screw to the other. Most of the time people band saw out a couple of pieces of plywood with V notches at the right height to support the work as the cut progresses. You take them out ahead of the tool and replace them behind.

I've cut a 3 1/2" 1 Acme double nearly 20 feet long that way.