Unimat SL

[Dave Gray]

I recently came across an Edelstaal Unimat SL miniature machining tool. Does anyone know anything about these? Are they any good?

[Bob Smalser]

A long-time gunsmith's and jeweler's favorite to make one-off screws and small parts. Google "Unimat lathe" for more info.

Yes, they are very good.

http://i15.ebayimg.com/04/i/001/12/e7/983e_1.JPG

[Dave Gray]

Thanks Bob. The one I came across doesn't appear to have all the accessories shown in the above picture but has many of them.

[Bob Cleek]

Parts and accessories are still available, although the Unimat hasn't been made for a long while. I'd tell you it was junk and then offer to take it off your hands for you, but, truth be told, they are one of the "holy grails" of the used tool market. What a Unimat is, actually, with all the attachments, is a minature ShopSmith machine... All the main power tools in one, in minature. Check out Gerald Wingrove's book, "The Techniques of Ship Modeling" for an excellent treatment of all the wonderful things that can be done on a Unimat.

http://www.geraldwingrove.com/

[Dave Gray]

The one I found was still in its original box. It had a sales catalog indicating it cost $135 in 1968. Interesting hits on Google for Unimat - I even found a Unimat forum! well, actually a mailing list:
http://finance.groups.yahoo.com/group/UNIMAT/

[Canoeyawl]

They won't cut threads...

[Bob Smalser]

They won't cut threads...

Yes, they will cut threads. With the correct attachment they'll stand up and yodel a nice tenor, let alone most normal lathe and mill functions.

http://unimat.homestead.com/belts.html

What they won't do however, is replace a full-sized mill if you need one. A M1911 slide fits in there just fine but is too heavy a workpiece for the limited mass of the machine to overcome the vibration of the cutting tool, regardless of how you mount the machine. The lighter M1911 barrel bushing however, can be turned very nicely.

And like so many old combination tools, the value is in the tooling, not the machine. You can buy the machine for a hundred bucks. With a nice set of tools and attachments....figure $500 and up.

[Canoeyawl]

I don't see any lead screw in the photo there. How does it work, Dreading?

[Bob Smalser]

http://www.blueridgeshoponline.com/images/product_401_lg.jpg

http://www.blueridgeshoponline.com/product.sc;jsessionid=D47DBCB57C99C9EB1F7215627F7A CE75.qscstrfrnt02?categoryId=31&productId=401

And fabricating your own:

http://www.cartertools.com/brooketh.html

[Canoeyawl]

Well, that’s kind of a stretch.
My bench vise will cut threads with an attachment like that!

[Bob Smalser]

Most screws in restoration gunsmithing are cut in a bench vise, using blanks and a die. It's the fancy, engraved heads that often go beyond the capability of the drill press and file method. Or replacing a broken screw in an oddball thread where if the die can be found at all it costs 80 bucks for a one-time job.

If you're fixing mechanical things made before 1900, you can expect to deal with oddball thread sizes as a matter of routine. While there were certainly better lathes for this than the Unimat, for a hundred bucks they added a lot of capability to the one-man shops more common when these were made.

[Canoeyawl]

We call those hand cut screws "drunkin' threads" and they are difficult to duplicate. Especially when they are a double lead not exactly 180° opposed.