Brown and Sharp 2G screw machine ?

[xtal_01]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

 

[rklopp]

A screw machine is not very efficient to set up and run unless you’re making thousands of identical parts.

 

[xtal_01]

A screw machine is not very efficient to set up and run unless you’re making thousands of identical parts.

That is what I suspected. I have never worked in a production shop ... thus never seen one.

 

[Richard Carlstedt]

He most likely would want a B & S Model 00 which does maximum screw sizes of 5/16 dia x 2 " long
"IF" he went that way......... but the small CNC lathe is a much better idea. And I believe the mentioned Model "2 G" is for 2" diameter stock . Depending on the work, you have to be prepared to make cams for a B & S machine . The inventory of cams is for the previous owners work
One thing easier for him is to buy a Geometric Die Chuck and the thread inserts to match requirements and use on a regular small lathe
Rich

 

[xtal_01]

He most likely would want a B & S Model 00 which does maximum screw sizes of 5/16 dia x 2 " long
"IF" he went that way......... but the small CNC lathe is a much better idea. And I believe the mentioned Model "2 G" is for 2" diameter stock . Depending on the work, you have to be prepared to make cams for a B & S machine . The inventory of cams is for the previous owners work
One thing easier for him is to buy a Geometric Die Chuck and the thread inserts to match requirements and use on a regular small lathe
Rich

WOW ... you can teach an old machinist new tricks! I have never seen a Geometric Die Chuck ... just watched a video ... very nice if I had lots of the same thread to cut!

What do the cams on the B & S do? Do they set the pitch or do they set the length or ?

Thanks!

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

If need book from Bronw in Sharp let me know I have one shelf like new.

The one had only use 2hp

Dave

 

[timo_gross]

Maybe that is of interest. (I found it fascinating) The cams are basically the G-code of the 1940ies?

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

You find it simpler to just a few standard cams and do threading in lathe or drill press.
It is real pain to do thread on 2G. .

I own a 2G and 00

 

[william_b_noble]

Tell your friend to Pat no more than one half is value as scrap metal. After pulling a few good parts off it, the rest will become scrap unless someone else wants parts for their machine

 

[ajoeiam]

Maybe that is of interest. (I found it fascinating) The cams are basically the G-code of the 1940ies?

Nope actually better.
The art of making cams is NOT simple yet a well set up cam operated machine is faster than the contemporary CNC machinery.
Where the screw machine does poorly is on setup time - - - it takes a skilled knowledgeable individual time.
Haven't set up any myself but was told that it was not unusual to take a day to setup such a beast. Not an issue if you were going to run it for say 6 months running that one part but a right royal PITA if you were wanting only say 24 hours worth of production.
The last that I heard for production on brass fittings screw machines were still the way to go - - - largest number of finished pieces per minute.
So if your selling parts in quantities of 100k or larger - - - worth looking into. Dunno if any company is ordering that way any more.
Seems like JIT is the mode de jour - - - - even when it really doesn't work - - - - many many reports of this kind of breakdown especially from 2020 to 2022. Haven't heard so much in the last while but no all clears yet.

 

[mcostello]

Set up time? I spent 5 years on a 2g and an 00g. I had set up time down to about 1 1/2 hours to the extreme displeasure of the boss. He wanted 45 minutes,I was slowly getting there but had a while to get there. A lot of times some of the previous could be saved and not tore down. We made a lot of 1/4" and 3/8" brass electrical circuit board standoffs. Face and chamfer first side, spot drill, drill,tap, feed out, chamfer 2nd side and part off took 6 seconds. Change turret depth, remove cross slide tools, Spot drill and chamfer,drill and tap and part done. 12 seconds a part. Speed was 3000 rpm I think, what it tapped at I don't remember. 12' bars don't last long with a 2" part. Longest We did was around 6" seldom done though.

 

[timo_gross]

Set up time? I spent 5 years on a 2g and an 00g. I had set up time down to about 1 1/2 hours to the extreme displeasure of the boss. He wanted 45 minutes,I was slowly getting there but had a while to get there. A lot of times some of the previous could be saved and not tore down. We made a lot of 1/4" and 3/8" brass electrical circuit board standoffs. Face and chamfer first side, spot drill, drill,tap, feed out, chamfer 2nd side and part off took 6 seconds. Change turret depth, remove cross slide tools, Spot drill and chamfer,drill and tap and part done. 12 seconds a part. Speed was 3000 rpm I think, what it tapped at I don't remember. 12' bars don't last long with a 2" part. Longest We did was around 6" seldom done though.

So it is possible to get a part e.g. like this one

out of a screw machine 90 min after receiving the drawing?

I have no insight how it actually works . I was under the impression that the cams need to be made to specification of the part.
And that for certain shapes form tools had to be made.
Hard to immagine that someone throws a drawing at me and 90 min later I am getting parts out.


Greetings Timo

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

A screw machine can simple to setup or very time consuming.

Unless you are do a long run over 10,000 parts avoid threading and complex setups.

2 or 3 sets cams can do most work under 3,00p parts.

I also had Trub screw machines. On machine I keep to just one set of cams. The parts just took a little long to do parts. But got job done fast. But very fast setup and setup was fast too.

Dave

 

[mcostello]

I suppose it would be possible to have parts that quick. Just not by Me.

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

A screw machine can simple to setup or very time consuming.

Unless you are do a long run over 10,000 parts avoid threading and complex setups.

2 or 3 sets cams can do most work under 3,00p parts.

I also had Trub screw machines. On machine I keep to just one set of cams. The parts just took a little long to do parts. But got job done fast. But very fast setup and setup was fast too.

Dave

 

[mcostello]

One tip I was shown was when threading with a Geometric die threading head was , Do not be afraid to change the position of the chasers. Instead of 1-2-3-4, try 2-3-4-1 etc. We also changed the positions in the holders,Try a different holder with the 1-2-3-4. For one job We could not get to run right the Boss tried 1-3-2-4 ang got it to work. We had a chaser sharpener and a surface grinder to sharpen the dies in. Some times things go against common sense to work.

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

The Brown and Sharp book goes in detail for threading.
The threading uses cams for threading and tapping.

It also has thd rake angle for turn tools. This works great in engine lathes too.

Dave

 

[SmithDoor]

I am 61 and have worked as a machinist most of my life.

That said, I have never been in a shop with an automatic screw machine.

A friend who owns a small repair shop (he repairs Victrola's and such) just called and said he had been offered one very cheap.

It is a Brown and Sharp 2G ... and he says it has "lots of cams" with it.

I just looked one up and just wanted to make sure I am on the right track.

First, I don't know what the cams are for. My best guess it that they "program" the length of the cut and the diameter.

I am also guessing that the machine uses gears to set the pitch of the thread (just like an older manual lathe) .. thus you would need many many gears to get "every" thread possible.

He was interested because he has many many odd screws that can not be purchased. He said almost all are under 1/4" dia and less than an inch long.

If I am reading the spec's right, I think this is also way too big .... looks like it can make 1 1/4" bolts so I am guessing 5 or 7 1/2 hp?

I suggested a very small CNC lathe. Because it is programmable, you can just program any thread you wish into it.

Am I correct about the screw machine?

Thanks ... Mike

When a lot work a tapping head in drill press.
I thinking of buying lead screw tapper fof both taps and dies.
I found you could do about 6 tapped parts per minute or 360 parts per hour in drill press.
A lead screw tapper is faster.

FYI My parts had threads both ends.

Dave