Half nut restoration


edward4583@...
 

Glen,
I posted on this around January. I had mine built up with WELCO 14 BARE
nickel silver alloy. I just got my 9" running last week and the halfnuts I
rebuilt with this procedure are as good as a new set if not better. Here are
a few added thoughts in addition to the article.
1. I did all my work on a Bridgeport mill. This procedure can be done on the
lathe as in the article but the mill setup is sturdier
2. I bored the original threads out to .85 dia. I reasoned this would leave
.05 of alloy to act as a "base" for the threads.
3. The halfnuts appear to be made from a single casting and split down the
middle with a 1/8 cutter after all factory machinery is complete. When I
sized and cleaned up the silver solder I left the center portions heavy so
there would be .005 or less between the two nuts when in the fixture. (In the
fixture the nuts are in the engaged position on the lathe.) In hindsight I
believe this step was the basis for my threads coming out as good as they
did. I'll explain. I purchased a new tandem acme tap for this project and
during tapping I had to add clamps over the threaded portion of the nuts as
the casting would flex away from the tap. I tapped about 1/4 turn and backed
out. I did this while advancing 1/8 to 1/4 turn each time. By having a full
diameter of metal around the tap I experienced none of the "breakout" that
would have been felt with the 1/8" gap between the nuts. Also, you can
purchase a single stage acme plug tap for about 1/3 the price of a tandem.
Don't even try to do this with an acme plug tap. I think the nuts would break
from the forces required to remove all the metal with the single thread
former on the plug.
I have spent the last year rebuilding my 9" and at some point in time I plan
to post pictures in the files sections so the group can see my toys. In this
was to be pictures of these nuts and the fixture. If you have any questions
feel free to contact me.
Keep turning!
Ed
9" Model A
(Broken file)
(hacksaw)


gorvil
 

Hi All,

I built the fixture described in HSM for restoring half nuts. I have
bored out the old threads and now I am thinking of silver soldering a
bronze sleeve in the resulting hole to be threaded 3/4 " x 8 Acme.

I have never silver soldered cast iron. I am a bit leary of brazing
bronze as the melting points may be incompatible.

Any thoughts?

Glen Ree


gorvil
 

--- In southbendlathe@y..., "gorvil" <Gorvil@a...> wrote:
Hi All,

I built the fixture described in HSM for restoring half nuts. I
have
bored out the old threads and now I am thinking of silver soldering
a
bronze sleeve in the resulting hole to be threaded 3/4 " x 8 Acme.

I have never silver soldered cast iron. I am a bit leary of brazing
bronze as the melting points may be incompatible.

Any thoughts?

Glen Ree
Somehow my name got shortened

Glen Rees


gorvil
 

--- In southbendlathe@y..., "gorvil" <Gorvil@a...> wrote:
--- In southbendlathe@y..., "gorvil" <Gorvil@a...> wrote:
Hi All,

I built the fixture described in HSM for restoring half nuts. I
have
bored out the old threads and now I am thinking of silver
soldering
a
bronze sleeve in the resulting hole to be threaded 3/4 " x 8 Acme.

I have never silver soldered cast iron. I am a bit leary of
brazing
bronze as the melting points may be incompatible.

Any thoughts?

Glen Ree
Somehow my name got shortened

Glen Rees
I don't know what is going on here.

Glen Reeser .......


Randy <rpedersen@...>
 

Glen:

That's alright it happens to us all eventually. ;-)

Randy Pedersen
Atlas 618
South Bend 9" A
South Bend 9" C
Enco Mill Drill Model 1100
Salina, KS
rpedersen@kscable.com

----- Original Message -----
From: "gorvil" <Gorvil@aol.com>
To: <southbendlathe@yahoogroups.com>
Sent: Friday, March 22, 2002 11:02 PM
Subject: [southbendlathe] Re: Half nut restoration



I don't know what is going on here.

Glen Reeser .......


Steve Odle <sbodle@...>
 

Help! One of my students busted the gears on the lead screw's drive on
wends. I forgot which lathe that was, but believe it is one of my
Clausing's? Can someone help with a source to by new/ used gears. These
belong to the high school where I began teaching this year. Boy you can
forget a lot when you haven't touched something in ten years! Thats how long
it's been since I ran a lathe at SIUC! Help! thanks in advance guys! Steve
Odle AVC Instructor Mt. Vernon,IL.

-----Original Message-----
From: gorvil <Gorvil@aol.com>
To: southbendlathe@yahoogroups.com <southbendlathe@yahoogroups.com>
Date: Friday, March 22, 2002 11:02 PM
Subject: [southbendlathe] Re: Half nut restoration


--- In southbendlathe@y..., "gorvil" <Gorvil@a...> wrote:
--- In southbendlathe@y..., "gorvil" <Gorvil@a...> wrote:
Hi All,

I built the fixture described in HSM for restoring half nuts. I
have
bored out the old threads and now I am thinking of silver
soldering
a
bronze sleeve in the resulting hole to be threaded 3/4 " x 8 Acme.

I have never silver soldered cast iron. I am a bit leary of
brazing
bronze as the melting points may be incompatible.

Any thoughts?

Glen Ree
Somehow my name got shortened

Glen Rees
I don't know what is going on here.

Glen Reeser .......



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catboat15@...
 

In a message dated 3/22/2002 8:58:15 PM Pacific Standard Time, Gorvil@... writes:


I am a bit leary of brazing
bronze as the melting points may be incompatible.



Use a low temperature silver solder such as EasyFlo or PhosCopper.  Both melt and run far below the melting point of bronze.  Some here will not use PhosCopper on boilers because of the sulfer products in coal fired locomotives,  so don't burn coal on your lathe if you use PhosCopper ;-]

John Meacham
California High Desert
12 inch Atlas, Minimill, rusty file


catboat15@...
 

In a message dated 3/23/2002 1:47:04 AM Pacific Standard Time, edward4583@... writes:


Ed
9" Model A
(Broken file)
(hacksaw)


Ed how about trading your broken file for a rusty one?

John Meacham
California High Desert
12 inch Atlas, Minimill, rusty file


edward4583@...
 


  |Ed how about trading your broken file for a rusty one?
John,
Had one but it broke!
Ed


gorvil
 

Thanks for the reply Ed,

My thinking was along the same lines as yours. I bored out the old
threads to about .830 and planned to silver solder a sleeve turned
from a bronze casting sprue. The extra material would hold the two
halves together during the threading operation. A hack saw and a
broken rusty file would do to separate the two halves and clean up the
saw kerf.

I purchased a tandem Acme tap on E-bay a couple of months ago and I
have been itchin to try it ever since.

Glen Reeser....

--- In southbendlathe@y..., edward4583@a... wrote:
Glen,
I posted on this around January. I had mine built up with WELCO 14
BARE
nickel silver alloy. I just got my 9" running last week and the
halfnuts I
rebuilt with this procedure are as good as a new set if not better.
Here are
a few added thoughts in addition to the article.
1. I did all my work on a Bridgeport mill. This procedure can be
done on the
lathe as in the article but the mill setup is sturdier
2. I bored the original threads out to .85 dia. I reasoned this
would leave
.05 of alloy to act as a "base" for the threads.
3. The halfnuts appear to be made from a single casting and split
down the
middle with a 1/8 cutter after all factory machinery is complete.
When I
sized and cleaned up the silver solder I left the center portions
heavy so
there would be .005 or less between the two nuts when in the
fixture. (In the
fixture the nuts are in the engaged position on the lathe.) In
hindsight I
believe this step was the basis for my threads coming out as good as
they
did. I'll explain. I purchased a new tandem acme tap for this
project and
during tapping I had to add clamps over the threaded portion of the
nuts as
the casting would flex away from the tap. I tapped about 1/4 turn
and backed
out. I did this while advancing 1/8 to 1/4 turn each time. By having
a full
diameter of metal around the tap I experienced none of the
"breakout" that
would have been felt with the 1/8" gap between the nuts. Also, you
can
purchase a single stage acme plug tap for about 1/3 the price of a
tandem.
Don't even try to do this with an acme plug tap. I think the nuts
would break
from the forces required to remove all the metal with the single
thread
former on the plug.
I have spent the last year rebuilding my 9" and at some point in
time I plan
to post pictures in the files sections so the group can see my toys.
In this
was to be pictures of these nuts and the fixture. If you have any
questions
feel free to contact me.
Keep turning!
Ed
9" Model


gorvil
 

Hi John,

One of my many other hobbies is jewelry making (let's call it
investment casting here, it sounds more macho). I was intending to use
some of the solder I use for soldering silver to silver. I have
several different grades "hard, medium, eazy, extra eazy". They are
intended to be used in multiple step fabrication processes where the
next solder operation uses a lower temp solder than the last. This
worked fine on the cross slide nuts I made, but that was soldering
bronze to bronze. I have never tried it on cast iron.

Glen Reeser ...



--- In southbendlathe@y..., catboat15@a... wrote:
In a message dated 3/22/2002 8:58:15 PM Pacific Standard Time,
Gorvil@a...
writes:


I am a bit leary of brazing
bronze as the melting points may be incompatible.

Use a low temperature silver solder such as EasyFlo or PhosCopper.
Both melt
and run far below the melting point of bronze. Some here will not
use
PhosCopper on boilers because of the sulfer products in coal fired
locomotives, so don't burn coal on your lathe if you use PhosCopper
;-]

John Meacham
California High Desert
12 inch Atlas, Minimill,


gorvil
 

Hi Ed,



Thanks for the reply. I had the same thought as you about leaving some room for thread adhesion, but I was also thinking that a sleeve soldered into the half nuts would solve the problem of the two halves wanting to separate. I bored the hole out to about .830 and turned a piece of bronze sprue from the bronze casting class recycle bin to fit. This will leave a thin web between the two halves that I can remove with my dull hacksaw and clean up with my broken rusty file.



I bought a 3/4" x 8 tandem Acme tap on e-Bay a few months ago and I have been itchin' to try it.



Glen Reeser

--- In southbendlathe@y..., edward4583@a... wrote:

Glen,
I posted on this around January. I had mine built up with WELCO 14 BARE
nickel silver alloy. I just got my 9" running last week and the halfnuts I
rebuilt with this procedure are as good as a new set if not better. Here are
a few added thoughts in addition to the article.
1. I did all my work on a Bridgeport mill. This procedure can be done on the
lathe as in the article but the mill setup is sturdier
2. I bored the original threads out to .85 dia. I reasoned this would leave
.05 of alloy to act as a "base" for the threads.
3. The halfnuts appear to be made from a single casting and split down the
middle with a 1/8 cutter after all factory machinery is complete. When I
sized and cleaned up the silver solder I left the center portions heavy so
there would be .005 or less between the two nuts when in the fixture. (In the
fixture the nuts are in the engaged position on the lathe.) In hindsight I
believe this step was the basis for my threads coming out as good as they
did. I'll explain. I purchased a new tandem acme tap for this project and
during tapping I had to add clamps over the threaded portion of the nuts as
the casting would flex away from the tap. I tapped about 1/4 turn and backed
out. I did this while advancing 1/8 to 1/4 turn each time. By having a full
diameter of metal around the tap I experienced none of the "breakout" that
would have been felt with the 1/8" gap between the nuts. Also, you can
purchase a single stage acme plug tap for about 1/3 the price of a tandem.
Don't even try to do this with an acme plug tap. I think the nuts would break
from the forces required to remove all the metal with the single thread
former on the plug.
I have spent the last year rebuilding my 9" and at some point in time I plan
to post pictures in the files sections so the group can see my toys. In this
was to be pictures of these nuts and the fixture. If you have any questions
feel free to contact me.
Keep turning!
Ed
9" Model A
(Broken file)
(hacksaw)


edward4583@...
 

Glen,
Sounds like a plan. By using a sleeve and then splitting after tapping you
will probably not see the two half's flexing away from each other while
tapping. Let us know how this method turns out.
Ed