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Screw machines as a hobby?

toastydeath

Hot Rolled
Joined
Jan 6, 2007
Location
Newark, DE
Some of the recent threads got me thinking more about this.

I'm fascinated by rotary transfer machines and screw machines. I haven't had the chance to work near or around them, so far. Does anyone here own a small screw machine that they use in a home shop or small business capacity? Used, small machines seem inexpensive, and not a bad skill to learn. Is the whole process way more expensive than it seems?

If, say, in the next few years I wanted to pursue camming and setting a small screw machine in more of a hobby/weekend work capacity than serious production, where should I start learning? Note, I'm not concerned that it's an inefficient way to make smaller runs of stuff, it's just something I'm deeply interested in and would like to spend time/money pursuing.
 
I still have a couple of single spindle autos.I believe you guys call them screw machines.They get used now and again and on the right job there is nothing to beat them.If I was looking for a small machine,I would go with a Traub,various capacities but a 1" one only measures about 18" x 36" without the bar tube.To learn about camming and cam design,try and find the Brown & Sharp red book.It will fascinate you.These books turn up on Ebay UK from time to time so I suppose you will also get them on Ebay.com
Mark.
 
They are cool as heck, make sure to get one new enough to have central oiling. Collets and feed fingers are another must have. Beyond that you can make the cams...esp if you home build a cnc mill :).

00 and 0 are neat machines but I think I would go a bit bigger for what your talking about...the little buggers are faster but limited as to how large of stock they can run. If you find one with the third slide that works down from 12 oclock above the spindle that is a nice add-on to have.

They make magical sounds when they run :)

Bill
 
00 and 0 are neat machines but I think I would go a bit bigger for what your talking about...the little buggers are faster but limited as to how large of stock they can run. If you find one with the third slide that works down from 12 oclock above the spindle that is a nice add-on to have.

I have many B&S OG screw machines, first one I bought & put in my garage in 1973. You can run 1" stock with an OG with an outside feed finger. There is a cam & tool book on Ebay right now. I have a "red" book I might put up someday.
 
do watch the auctions
i got a little 7/16 acme that went for basically scrap
cutest little nipper you ever seen
if you take one from "working when pulled from production"
to
"can be seen under power"
there might be a few bucks return
 
I'm also interested in these small screw machines. Can anyone suggest a good website to learn more about these machines and how they work? Thanks!
 
Tapping on a Traub, spindles run same direction and neither reverse however the tap backs out just fine. I’ll never forget first seeing that at the first shop I worked at, I was fresh out of tech school, it really amazed me.
 
FWIW - If a fellers got the roof - I would git a cheap Acme. You can pick up an older 9/16" 6 banger for $1500 in running condition at ANY sale.

This would likely have a set of cams and gears on it at that time - and you would be surprised what you can doo with nothing on a multi...

Some folks that run short runs just cam them long and cut air for a bit on each cycle if there is more stroke than needed.

The 1" and 1-1/4 machines are bringing more $ now than they had been - but if you find an old one that aint all that nice - you can likely pick it up cheap too. 4 bangers are actually good - quick setup machines and will blow the doors off any single - and you don't have specific cams for each and every job! (Now if your just dooin' chmfr/cutoff - then one set of cams would werk for many jobs on a single...)

I sold my Brownie yrs ago and stuck with the multis. In anything short of repeating 200 pc runs and chmfr/cutoff the singles are almost pointless. ... but they doo take up less space.

On the multis - cams are NOT specific to a certain job like on the singles.

Acmes have a few diff type cams on each machine - where a Greenlee uses all the same cams everywhere - with a rack/pinion for the endslide - but you don't really want wunna those noisy contraptions!

Think Snow Eh!
Ox
 
What kind of collets do the machines take (Acme multispindles in particular)? I've seen some 2" multispindles go for fairly inexpensive, and I'm just wondering where one would find a set of six to eight collets for every size stock you use. Doesn't that get pricey? Or do you bore your own?

Ox -

Can you elaborate on the cams not being specific to a particular job? Are you referring to setting the tool so you just cut air, or is there some kind of rocker adjustment for that?

What kind of setup times are you looking at on a multi, provided you've got the tooling/etc already made and on hand?
 
So who in this thread that owns a screw machine would be willing to do a short run of a couple different screws I'm looking to get made??

I got 3 different type I'm gonna need about a 1000 of each.

Thanks
Grinch
 
toastydeath

What does a person look for in a single spindle automatic (AKA screw machine)?
First, there are different fundamental types of screw macines. First when it comes to single spindle machines there is the American-type (AKA Brown & Sharpe-type) single-spindle screw machine and the Swiss-typesingle-spindle screw machine. You can find a bit more information here:

http://www.toolingu.com/class_class_desc.aspx?class_ID=200160
 
"Construction and use of automatic screw machines" is the earlier version of the red book.I have two brand new ones here.
As ox said the multis are the easier machine to tool up although I don`t know about collet and feeder prices your side of the water.Here a set for a six spindle 2" Acme will set you back $2500.
For fast setting there is nothing to beat a Wickman and I believe W&S used their system as well.No cams to change,just adjust strokes,change gears,feeders and collets and of you go.Can be done in 4-5 hours.No good for long running heavy cutting jobs though.
A 2" Gridley can take three days for a dedicated setup on high volume parts.
I`ve got BSA Gridleys,New Britans and Wickmans here doing nothing if you want to ship them.Unfortunately no work worth setting for here now all gone to India,China and Eastern Europe.
For 1000 parts non repeating,stick it on a cnc.
Mark.
 
Is the "red" B&S book titled "Automatic Screw Machines: Construction and Use of Brown and Sharp"?

Thanks,
Phil

Nope, mine says "Automatic Screw Machine Handbook"
364 pages
 
As Mark said - the Wickmans are the quick setup machines as they have adjustable strokes on each position - or something like that. ??? I don't know much aboot them. I have looked at the newer ones as they supposedly are able to spindle stop ON THE FLAT of hex bar somehow. It is a sorta expensive attachment - but one for an Acme 10 yrs ago through Acme was $70 or $80K, but no-one there had ever seen one. :eek:

We did our cross werk on the flats in a transfer machine 2nd op. ;)

Wickmans are known for sloppy pins and pin holes as they age from what I have heard. ???

-----

Personally I run "Master" collets in anything of any size. The 2" machine has such fine and large threads that my main man yrs ago spent one full 10 hr day just changing collets and pushers. If they fight you - it will take a long time as you can't reach around the housing on that large'a machine. Masters will pay fer themselves quickly as you only need the pads after that - and pads for S20 are ??? $60/each?

Also - I run almost strictly Excel (sp?) master pushers too. Same concept - but a WAY better pusher than cage IMO. Just don't think your pullin' the bar out backwards w/o an act of Congress!

The 9/16" / 1" machine (same machine almost) you can change collets and pushers pretty quickly and they are cheap/used - so no point running masters down there...

On my 2" I finger it costs $600 for a new set (6 banger) of collet pads/pusher pads for each new size. I doo NOT recommend buying used pusher pads or even pushers if possible. Those are wear items.

Git a subscription to Automatic Machining Magazine and maybe The Graff Monthly and you will git all the info for used equip/tooling distributors you could want. ESPECIALLY the July issue of Automatic Machining.

----

As per cutting air?

Each slide has it's own cam to set the stroke for that toolslide. (Unless you alter the timing of the machine for reasons that I'm not gunna git into here) ...all slides start the cut and finish the cut cycle at the same time. So you need a cam that is AT LEAST the length needed - but longer will be fine too. You would just cut air for a while before you hit metal. If your cammed "long" then you would just have some wasted cycle time otherwise you would overfeed your tools...

The best way to learn it - is to doo what I did...

When I bought a 2G Brownie - I brought it home - threw spark to it - and eventually found the feed lever and engaged it - and just watched it for a while 'till I had it fingered out.

I did the same on my first Acme.

Just take time to "think" aboot how it werks. I spent yrs dreaming up really wild setups for them - for jobs that never came through my door. Altered timing, dead spindles, add-on componants - just kewl stuff. The everyday stuff gets boring after while eh? (and more competative too...)

My first Acme setup was on a four banger that had three, (3), more than two - less than four, different threads on it! 1/4 pipe OD, 1/2-16 Acme OD, and .210-36 (?) valve core threads and seat ID. That was a VERY busy setup! (Although the tooling for the Acme didn't werk at first no-matter what I did - chenged type of tool and ran fine after that.) I had another part aboot ten yrs ago that I think I had 11 tools in the cut at once and another 3 (?) roll supports yet. Very deep drill ratio too. Job ran SUPER! Previous supplier had increadible runout troubles and even shipped parts with holes sticking out the sides on occasion.

Yeah - I think their impressive machines that only recently have changed from their WWII designs and even those aint really any more productive on the same parts. They are just better suited for todays materials and complex part geometries. (CNC type Index, DMG, Shutte' ...) Todays Wickmans and Euroturns aint really that much diff than the old ones. Just a few refinements like I said aboot the one attachment and they are faster. (Read lighter and won't last side by side to an 1950 Acme in the long run.)

Things to look for in purchasing an Acme:

1) First and by far the most important is end slide slop. The main toolslide runs back and forth on a "stem" and the bushings in the endslide wear. Put an indicator on it and a prybar to lift the endslide and see how bad. A few thousandths aint no biggy - but I have seen them come in here at .030 before - and that will creat LOTS of ghosts if you don't know it's like that!

2) Carrier slop. You can fit feeler guages between the top of the carrier and the casting. The carrier is the part that has the spindles in it and revolves 1/6 (1/8?) turn each cycle. I have a 1935 2-1/4 R4 that has been rebuilt and not ran all that much since and I cannot get ANY gauge in there at all! .004-.005 is considered tight on a 1-5/8-2" machine. You can werk around a sloppy carrier tho. Just don't put too big'a form tool in 1st position, or at least not a rough form in first with finish form in 2nd. ;) I've picked up the carrier on 1-1/4" dooing that! LOL!

I like'm. Just kant make a living on'm anymore. I am down to two 2"-6's inline anymore. I have 6 in cold storage that I hope to retrieve one day soon. Still - I may go see what I can pick up an 8 banger for next month - and maybe see what the Index's bring. :cool:

The others can go on aboot the singles...

Think Snow Eh!
Ox
 








 
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