Date   

Re: 3C vs. 6K

Jim B. <btdtrf@...>
 

I do have a write-up/how to, if you want.

 

Jim B.


From: SOUTHBENDLATHE@... [mailto:SOUTHBENDLATHE@...] On Behalf Of Gregg Eshelman
Sent: Wednesday, April 02, 2014 2:06 AM
To: SOUTHBENDLATHE@...
Subject: Re: [SOUTHBENDLATHE] 3C vs 6K

 

 

On 4/1/2014 6:04 PM, David Rysdam wrote:
> "Jim B. " writes:
>> You would need a taper adapter sleeve for your lathe, to take 3C if
>> you do not have one and a Nose piece if you do not have one
>
> Your offer of the 6K tooling is kind, but I would never be able to bring
> myself to alter something that isn't being made anymore.
>
> I see a taper adapter sleeve here:
>
> http://littlemachineshop.com/products/product_view.php?ProductID=2240&category=
>
> Looks a little pricey for something that would only take a couple hours
> to make. Of course, the accuracy would be far less, but then I don't
> need phenomonal accuracy. I just need something better than the 3 jaw is
> giving me when I clean up the backs of the rings.
>
> As for the nose piece--do you mean one that is different from the
> spindle nose piece I already use with the few 6K collets I have?
> Something specially shaped to the pot collet "head"?

Something like this perhaps?
https://www.flickr.com/photos/27748767@N08/11807014954/in/set-72157639469853874

That setup came with a 10" Montgomery Ward/Logan. Should fit any lathe
with an MT3 spindle taper and the standard thread for such spindles.

The "chuck" screws on, then a collet is inserted into the adapter and
slit into the chuck. Last, the external ring is screwed on. It's a solid
setup, seems like it would be quite accurate.

It appears to be shop made, can't find any collets like them, slightly
larger than the 3C or 3AT. No threads on the collets, they're held by
the external ring.

The largest ID I measure (at the back end) on the collets I have for it
is 0.622" (a skosh under 5/8"), that's larger than the 1/2" any 3C or
3AT can possibly hold if bored to maximum ID.

I'm willing to loan the set to someone to make detailed drawings and/or
to setup for a production run. Should work with any MT3 spindle and by a
simple thread change on the chuck, with other spindle threads.

The design would scale up to MT4 and similar size proprietary tapers to
enable stuffing the largest possible workpiece into a collet in the
spindle without a bulky chuck with lots of overhang.

The lathe was at one time owned by the Consolidated Vacuum Co. of
Rochester, NY. Likely bought new by CVC in 1941. CVC did some work for
NASA, never know but the lathe may have turned parts that went into some
of the early rockets.


Re: 3C vs. 6K

David Rysdam <david@...>
 

"Jim B. " <btdtrf@...> writes:
I do have a write-up/how to, if you want.
Yes, that would be helpful. I was realizing this morning that I want to
turn it between centers to get the taper and the threads concentric. Not
sure how I'm going to do the slits so far back in a rigid setup.


Re: 3C vs. 6K

Jim B. <btdtrf@...>
 

I think making your own collet for this project is a very good approach.

I have made 3C adapters in the past with little trouble.

 

Some years ago I bought a small collet mounted 3-Jaw off eBay. I actually wanted it for the index head on my Burke Mill which takes 3C collets. It was advertized as fitting a SB-9” Workshop lathe. I ASSUMED 3-C but when it arrived it was not 3-C. It was a Rivett #6. Apparently the seller had a complete set of Rivett collets adapted to his lathe.

I kept it and it just sat there for several years. One day I figured out how to remove the adapter and made a new one wit 3-C dimensions.

It went on without incident. It fits both my 9” lathe, the index head and, although I have never used it in this way, the vertical head on Burke.

I did use steel in this case.

 

 

Jim B.


David Rysdam writes:

Instead, I'm thinking about making my own 6K(ish) "soft collet" in
Al. In this PM thread:

http://www.practicalmachinist.com/vb/south-bend-lathes/collets-195569/

there are some dimensions, but I think the only vital ones are the
thread and the head angle. I think even the angle could be approximate
if there's no danger of damaging the spindle and it provides even
pressure all the way around. Then I can use my existing lever closer,
don't need an adapter, etc.

I've made similar collet-like things before, but gripped them in the 3
jaw. The repeatability wasn't there. This would fix that. Could also
make a 3 jaw version but mark where the jaws go--would save a chuck
change.

I just now realized that the other reason my collet-like things didn't
work so well was that I cross-cut them into 4 sections but then tried to
squeeze them with 3 jaws. Uneven pressure.


Re: 3C vs 6K

David Rysdam <david@...>
 

David Rysdam <david@...> writes:
For my decoder ring project, I think I want to use a pot collet (why are
they called that?) to clean up the back sides after parting. But I don't
want to chase down and pay for a 6K one.
Thanks for all the help, everyone. I think I probably do eventually want
to build up a 3C system because of the wider availability of collets,
but the startup cost for this project is too high.

Instead, I'm thinking about making my own 6K(ish) "soft collet" in
Al. In this PM thread:

http://www.practicalmachinist.com/vb/south-bend-lathes/collets-195569/

there are some dimensions, but I think the only vital ones are the
thread and the head angle. I think even the angle could be approximate
if there's no danger of damaging the spindle and it provides even
pressure all the way around. Then I can use my existing lever closer,
don't need an adapter, etc.

I've made similar collet-like things before, but gripped them in the 3
jaw. The repeatability wasn't there. This would fix that. Could also
make a 3 jaw version but mark where the jaws go--would save a chuck
change.

I just now realized that the other reason my collet-like things didn't
work so well was that I cross-cut them into 4 sections but then tried to
squeeze them with 3 jaws. Uneven pressure.


Question from new joiner

Brian Wood <wood_y@...>
 

Good morning from the UK,
 
I hope one of you can answer my simple questions. But first to introduce my interest. I am a Myford lathe owner with screw-cutting gearbox and I recently published some work in Model Engineers Workshop in the UK  on simplified gearing for cutting non imperial threads with simple one gear changes to the stud gear with matched gearbox combinations to achieve a wide range of Metric, BA, DP and Module pitches, as well as some rather obscure pitches using the standard 1/8 inch pitch leadscrew.
 
The subject interests me sufficiently to gather more  information together for other makes of lathe, fitted with gearboxes, to expand the publication of all this reference data into hopefully a more permanent book form. For this stage I need your help with these very popular lathes.
 
Specifically I need information on S B lathes equipped with the Metric gearbox and would like very much to correspond with an owner thus equipped for some detailed questions and answers. I hope someone can help me please
 
Kind regards
Brian Wood


Close calls with flying metal. Re: Question for the group: What was....

Gregg Eshelman
 

The closest call I ever saw in a shop was in my 7th grade shop class, in 1983-84.

The classroom had several long, sheet metal topped tables with a bench vise at each end.

The whole class was gathered around one table while the teacher demonstrated the correct and incorrect ways to use a center punch, on a piece of metal on the back anvil of the vise.

First the correct way, firm grip on the punch and give it a solid strike.

Second, the incorrect way, holding it gingerly with the fingertips then just *tink* it with the hammer.

The punch was supposed to just fall onto the table. Instead it ricocheted off the tabletop and flew straight as a bullet. About halfway down the left side, a student was leaning forward to get a good view. The punch went right through the left lens of the safety glasses and right past his eye. Didn't get any glass in his eye or strike his head outside his eye. Everything aligned just perfectly so the punch hit nothing but the glass lens, leaving a very neat hole.

After that, most of the students decided the big plastic safety goggles weren't so dorky looking because the safety glasses weren't so "safe" if they wouldn't deflect a chunk of flying metal. 'Course if it had deflected, it probably would've bounced to the right side of the table and stabbed someone else in an arm or head... (I've always wondered if the school later switched to polycarbonate lens glasses.)

Many years later, I was using a wire cup wheel on a bench grinder to remove the glued on remains of cork gaskets from a set of Ford V8 valve covers. Well, the wheel decided it really liked one of the covers, grabbed hold then swung it around and threw it at my forehead. *Thunk!*. Didn't leave a mark or even a dirty spot, didn't even hurt at all. ;)


I'm looking for 4C collets.

Gregg Eshelman
 

I have a need for a few 4C collets, 1/4" 1/2" 5/8" and 3/4". I have a 3/8", only one I do have. I don't need any 16th or 32nd or 64th or metric sizes, at least not right now.


Re: 3C vs 6K

Gregg Eshelman
 

On 4/1/2014 6:04 PM, David Rysdam wrote:
"Jim B. " <btdtrf@...> writes:
You would need a taper adapter sleeve for your lathe, to take 3C if
you do not have one and a Nose piece if you do not have one
Your offer of the 6K tooling is kind, but I would never be able to bring
myself to alter something that isn't being made anymore.

I see a taper adapter sleeve here:

http://littlemachineshop.com/products/product_view.php?ProductID=2240&category=

Looks a little pricey for something that would only take a couple hours
to make. Of course, the accuracy would be far less, but then I don't
need phenomonal accuracy. I just need something better than the 3 jaw is
giving me when I clean up the backs of the rings.

As for the nose piece--do you mean one that is different from the
spindle nose piece I already use with the few 6K collets I have?
Something specially shaped to the pot collet "head"?
Something like this perhaps?
https://www.flickr.com/photos/27748767@N08/11807014954/in/set-72157639469853874

That setup came with a 10" Montgomery Ward/Logan. Should fit any lathe with an MT3 spindle taper and the standard thread for such spindles.

The "chuck" screws on, then a collet is inserted into the adapter and slit into the chuck. Last, the external ring is screwed on. It's a solid setup, seems like it would be quite accurate.

It appears to be shop made, can't find any collets like them, slightly larger than the 3C or 3AT. No threads on the collets, they're held by the external ring.

The largest ID I measure (at the back end) on the collets I have for it is 0.622" (a skosh under 5/8"), that's larger than the 1/2" any 3C or 3AT can possibly hold if bored to maximum ID.

I'm willing to loan the set to someone to make detailed drawings and/or to setup for a production run. Should work with any MT3 spindle and by a simple thread change on the chuck, with other spindle threads.

The design would scale up to MT4 and similar size proprietary tapers to enable stuffing the largest possible workpiece into a collet in the spindle without a bulky chuck with lots of overhang.

The lathe was at one time owned by the Consolidated Vacuum Co. of Rochester, NY. Likely bought new by CVC in 1941. CVC did some work for NASA, never know but the lathe may have turned parts that went into some of the early rockets.


Re: what is it?

Gregg Eshelman
 

On 4/1/2014 3:56 PM, twombo@... wrote:

I really am not committed to any course of action other than making a
nice serviceable machine that I can do nice accurate work on. I am not
against havingthe bed on the 4 1/2' machine as they are, apparently
relatively uncommon. It will not go to waste, for sure. If you know of a
place to get the ways, saddle, and tailstock done in Nor Cal redone, I
am not against that at all.
Machines with enough travel to mill or grind a bed 4.5 feet long are not exceedingly common. A very swaybacked bed can be hand scraped but it's a lot of work.

The way the right end gearing works, it doesn't make much difference if you have the full length of the bed done.

What does cause issues is the relationship between the leadscrew and the carriage. The underside of the saddle must be built up, usually with a molded in place product like Moglice or Devcon Titanium putty or a glued on solid like Turcite or Rulon - which must then be milled to height, or the leadscrew and QCGB (if equipped) and carriage gear rack have to be lowered the amount the carriage ways have been taken down.

There are owners of 9" and light 10" South Bends who have simply setup the bed on a mill with enough X travel and carefully cut the ways straight down, using the right rate of feed to get a shiny surface, and been perfectly happy with the results.

The carriage and 'stock ways don't have to be cut down the same amount. A bit of difference in saddle to spindle height from original isn't going to mess things up.

Saddle to leadscrew height can't be changed on lathes with power cross feed. The gear mesh has to be right on. Much simpler to build up the saddle than move everything else down.

On a basic changegear lathe with no power feeds the top of the apron can be cut the same amount the carriage ways are cut. South Bend did that in production prior to their first QCGB in 1920 and on later lathes without gearboxes and power feeds, which is why it's easier to swap the entire carriage instead of just the apron when upgrading to power feed. (Lower cost lathe, save time and money by fitting the apron to the lathe rather than having everything match the blueprints more precisely.)

What it boils down to is how much work do you want to do or can do VS how much money do you want to spend fixing up a lathe? Some lucky sods happen to live close enough to shops with large enough grinders - and don't happen to specialize in extracting the wallets of machine tool owners through their noses. ;) I've heard of people getting a 9" SB bed ground for as low as $600 which is a heck of a lot less than a specialty shop will charge.


Re: Looking to buy, South Bend 10 Heavy, 11, or 13 - Houston Texas

sblatheman
 

14" Variable Speed South Bend lathe. Early 70's

Ted

On Apr 1, 2014, at 8:00 PM, <alco2350@...> wrote:

 

This was just posted today. What do you guys think?



Britt


Re: what is it?

Paolo Amedeo
 

Mike,
Apologies for interjecting myself in the conversation.

The "Bible" of reconditioning machines is a book written by Edward F. Connelly, titled "Machine Tool Reconditioning and Application of Hand Scraping"
If you search carefully, you can find it in PDF version on the Web. (I'm pretty sure that there is more than a link to it in a few PM threads).

I'd also suggest you to to read through these two PM threads (the second is work in progress):

http://www.practicalmachinist.com/vb/antique-machinery-history/lucas-horizontal-boring-mill-going-tuckahoe-161194/
http://www.practicalmachinist.com/vb/antique-machinery-history/american-pacemaker-lathe-restoration-259065/

Paolo
Damascus, MD

On 04/01/2014 08:02 PM, twombo@... wrote:

 

Any favorites in your reading list along these lines, Ed?

mike




Re: Looking to buy, South Bend 10 Heavy, 11, or 13 - Houston Texas

Paolo Amedeo
 

I'd say it has just suffered a very bad paint job.
IF (a big one) the machine is in good shape, it sounds a decent deal...

I don't know the "modern" South Bend much. Definitely, it doesn't look like there are many spare parts around for these ones...

Paolo

On 04/01/2014 08:00 PM, alco2350@... wrote:

 

This was just posted today. What do you guys think?



Britt


Re: Question for the group: What was....

druid_noibn
 

Safety Glasses - a wise decision.
On Tuesday, April 1, 2014 8:15 PM, David Rysdam wrote:
 
Edward Draper writes:
> My scariest moment was when turning the links for the parallel motion
> of the beam engine between centres to create a pleasing barrel shape. 
> Dug the tool in, the job bent in the middle and came flying out and
> hit  me right between the eyes.  Fortunately father always insisted on
> my wearing protective goggles, so I was completely unscathed. 
> "Scariest moments" thread anyone?   Eddie

Remember a couple weeks ago when I was asking about the parting tool
bending?

A few weeks before that, I was parting off and I suddenly heard a
*sproing* and a thump and it stopped cutting. I realized something was
wrong, then realized the parting tool was completely missing, THEN heard
a clang as it hit the ground. I found it a week later under a workbench.

Everyone in the workshop always wears glasses.



Re: School shop injuries Re: SB Lathes, Lathes, Lathes, Lathes... the uber New England auction!!!

Stanley
 

On gym incidents: An "errant" toss of an aluminum javelin during a recent gym class at the high school I abut ended up bridging 2 legs of a 23 kV transmission line. I heard that, before the substation tripped out taking down a section of the town, the hummmmm could be heard for almost a block.

Would have loved to have seen the expression on some faces that day!


From: Gregg Eshelman ;
To: <SOUTHBENDLATHE@...>;
Subject: School shop injuries Re: [SOUTHBENDLATHE] SB Lathes, Lathes, Lathes, Lathes... the uber New England auction!!!
Sent: Tue, Mar 25, 2014 7:22:56 AM

 

On 3/24/2014 8:56 PM, mark.jonkman@... wrote:
>
>
> I don't recall anyone losing anything or being injured by a machine in
> any of the schools I attended. I do know a few that got injured by a
> chuck key that Mr. Walker kept on his desk and threw across the shop at
> whatever kid hadn't removed the key from the lathe chuck after removing
> something or putting something into the chucks on the lathes. I don't
> think he ever aimed to hit anyone.. just scare the living sh@# out of
> everyone nearby.

When I was in jr. high, the metal shop teacher was doing a demo of the
proper, and improper use of the center punch.

The shop had long tables, topped with heavy gauge sheet metal. At both
ends of each was a vise.

First he showed the proper way, firm grip on the punch and give it a
solid hit on the piece of metal on the anvil part of the vise.

Then he showed the wrong way, lightly gripping the punch with his
fingertips then giving it a wee little tap. The intention was to have
the punch just fall to the table.

What happened was the punch flew out of his hand, ricocheted off the
tabletop, angled up and flew straight as a bullet right through* the
left lens of the safety glasses a boy was wearing. He was halfway down
the table, about five feet away. The punch missed actually hitting his
head and he didn't get anything in his eye. Didn't even use the
emergency eye wash/shower station. (Never pull this unless you are on fire.)

The only time that got used was when a student was laying out a project,
put the square over his shoulder then hopped backwards off his stool,
neatly hooking the loop with the square. The teacher just silently
handed him a mop.

*From then on I wore the dorky looking plastic goggles instead of the
"safety" glasses! If they couldn't stop a slow moving center punch, what
good would they be against anything else with sharp, pointy bits?

The only other incident of damage and mayhem I witnessed was in gym
class when a student was goofing around with a basketball and somehow
nailed one of the fluorescent lights 20-some feet overhead. Just had the
janitor come in and sweep it up. These days they'd evacuate the whole
school and call in a hazmat team.


Re: what is it?

Flash Gordon
 

Mike,

Here are three good ones:

http://www.wswells.com/

http://www.lathes.co.uk/southbend/index.html

and join southbendmanual group, that is our library, look through files section but post questions here not there:

https://groups.yahoo.com/neo/groups/southbendmanual/files


Ed S

At 08:02 PM 4/1/2014, you wrote:


Any favorites in your reading list along these lines, Ed?

mike

_


Re: 3C vs 6K

Jim B. <btdtrf@...>
 

I agree but these are designed to be altered.

You have already found the ones at tools4cheap.

There are some larger collets that do require a backing plate.

You do have to be careful.

 

Jim B.



Your offer of the 6K tooling is kind, but I would never be able to bring
myself to alter something that isn't being made anymore.

I see a taper adapter sleeve here:

http://littlemachineshop.com/products/product_view.php?ProductID=2240&category=


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Re: Question for the group: What was....

David Rysdam <david@...>
 

Edward Draper <eddie.draper@...> writes:
My scariest moment was when turning the links for the parallel motion
of the beam engine between centres to create a pleasing barrel shape. 
Dug the tool in, the job bent in the middle and came flying out and
hit  me right between the eyes.  Fortunately father always insisted on
my wearing protective goggles, so I was completely unscathed. 
"Scariest moments" thread anyone?   Eddie
Remember a couple weeks ago when I was asking about the parting tool
bending?

A few weeks before that, I was parting off and I suddenly heard a
*sproing* and a thump and it stopped cutting. I realized something was
wrong, then realized the parting tool was completely missing, THEN heard
a clang as it hit the ground. I found it a week later under a workbench.

Everyone in the workshop always wears glasses.


Re: 3C vs 6K

sblatheman
 

I have N.O.S. and used 3c collet sleeves for less
Send me an email.  
Ted

 

> You would need a taper adapter sleeve for your lathe, to take 3C 
I see a taper adapter sleeve here:

http://littlemachineshop.com/products/product_view.php?ProductID=2240&category=

Looks a little pricey for something that would only take a couple hours
to make. Of course, the accuracy would be far less, but then I don't
need phenomonal accuracy. I just need something better than the 3 jaw is
giving me when I clean up the backs of the rings.



Re: 3C vs 6K

David Rysdam <david@...>
 

David Rysdam <david@...> writes:
Looks a little pricey for something that would only take a couple hours
to make. Of course, the accuracy would be far less, but then I don't
need phenomonal accuracy. I just need something better than the 3 jaw is
giving me when I clean up the backs of the rings.
Oh, looks like this pair would be cheaper:

http://www.tools4cheap.net/proddetail.php?prod=3atnose
http://www.tools4cheap.net/proddetail.php?prod=3at3pot

Even if I never use the adapter for anything but that collet, it's still
cheaper than just the 3C adapter. I don't see any new 3AT collets being
sold anywhere, so that's a real possibility.


Re: 3C vs 6K

David Rysdam <david@...>
 

"Jim B. " <btdtrf@...> writes:
You would need a taper adapter sleeve for your lathe, to take 3C if
you do not have one and a Nose piece if you do not have one
Your offer of the 6K tooling is kind, but I would never be able to bring
myself to alter something that isn't being made anymore.

I see a taper adapter sleeve here:

http://littlemachineshop.com/products/product_view.php?ProductID=2240&category=

Looks a little pricey for something that would only take a couple hours
to make. Of course, the accuracy would be far less, but then I don't
need phenomonal accuracy. I just need something better than the 3 jaw is
giving me when I clean up the backs of the rings.

As for the nose piece--do you mean one that is different from the
spindle nose piece I already use with the few 6K collets I have?
Something specially shaped to the pot collet "head"?

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