3 TPI Acme thread
 

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

3 TPI Acme thread
 

On Mon, 29 Sep 2008 17:34:30 -0500, Wayne
wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

Mine switches from 9 to 4-1/2 tpi by switching from a 24 tooth stud
gear to a 48 tooth. If I could find a 72 tooth, that'd cut 3 tpi.

Pete Keillor

3 TPI Acme thread
 

On Mon, 29 Sep 2008 17:34:30 -0500, Wayne
wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

==========
It depends on your lathe, and what change gears you have, can buy
or can make. Even with a quick change box you can generally
change some external gears between the spindle and box and get a
whole other range of threads.

Bear in mind that your thread dial may not work with the new
gears and you will have to leave the half nut engaged. Also note
that cutting 3 TPI with a 8 TPI lead screw requires the lead
screw revolve about 3 times [8/3s] faster than the spindle and
this can be a considerable load/strain on the gear train. Some
of the old old lathes had a set up to drive the lead screw to
reduce the strain for very course pitch threads. Acme threads
are tough anyhow so take it easy.

A good reference is http://lindsaybks.com/bks7/sscut/index.html @
$4.95

Let the group know how your make out and good luck.


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

3 TPI Acme thread
 

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?

Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

3 TPI Acme thread
 

"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?

Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

3 TPI Acme thread
 

On Sep 29, 7:54 pm, "Pete C." wrote:
"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?

Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

How about casting a new nut from moglice, babbitt, zamak, etc. using
the unworn (less worn) section of the existing screw as the core for
the mold?

Wolfgang

3 TPI Acme thread
 

"Wayne" wrote in message
...
A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.


Once you actually measure it, on the odd chance that it matches, I have a 1
1/8-3 lh acme unitap laying around.

You are welcome to borrow it.

If it doesn't match, good luck anyway.

Paul K. Dickman

3 TPI Acme thread
 

Pete Keillor explained :
On Mon, 29 Sep 2008 17:34:30 -0500, Wayne
wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

Mine switches from 9 to 4-1/2 tpi by switching from a 24 tooth stud
gear to a 48 tooth. If I could find a 72 tooth, that'd cut 3 tpi.

Pete Keillor

I don't think I'd get into looking for different gears for a one off
project such as this one.

Wayne D.

3 TPI Acme thread
 

Pete C. formulated the question :
"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?

Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

Could be metric since I think he said it came from the old country.
He does have another one, so maybe it isn't all that important for him
to get it fixed. All I hear is it's too heavy. A mill or lathe is
heavy.

I missed that Enco had acme rods/nuts. Mcmaster's prices would put a
repair at about half the cost of the unit. Enco's prices would be
feasible.

I didn't even know about multi lead screws until I researched
a mini acme rod for a small stepper motor. Wasn't an even number
of TPI. If you look on the end, do you see 2 starting points?
What's the purpose of them?

Wayne D.

3 TPI Acme thread
 

3 TPI Acme thread
 

Paul K. Dickman laid this down on his screen :
"Wayne" wrote in message
...
A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.


Once you actually measure it, on the odd chance that it matches, I have a 1
1/8-3 lh acme unitap laying around.

You are welcome to borrow it.

If it doesn't match, good luck anyway.

Paul K. Dickman

Wouldn't it be great if that was the size then? At least 3 tpi exists
somewhere. I've only done an external single point thread once, with
a couple of practice pieces prior. It was done in plastic for the
bathtub drain plug. I was a 1" 20 TPI plug, which I couldn't find
anywhere.
The only internal tapping I've done is with taps.

Wayne D.

3 TPI Acme thread
 

F. George McDuffee was thinking very hard :
On Mon, 29 Sep 2008 17:34:30 -0500, Wayne
wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

==========
It depends on your lathe, and what change gears you have, can buy
or can make. Even with a quick change box you can generally
change some external gears between the spindle and box and get a
whole other range of threads.

Bear in mind that your thread dial may not work with the new
gears and you will have to leave the half nut engaged. Also note
that cutting 3 TPI with a 8 TPI lead screw requires the lead
screw revolve about 3 times [8/3s] faster than the spindle and
this can be a considerable load/strain on the gear train. Some
of the old old lathes had a set up to drive the lead screw to
reduce the strain for very course pitch threads. Acme threads
are tough anyhow so take it easy.

A good reference is http://lindsaybks.com/bks7/sscut/index.html @
$4.95

Let the group know how your make out and good luck.


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

Thanks for the input. Everything I do seems to take a long time.
I have started experimenting taking bigger cuts, but still am
conservative. I'd never make it in the real world of machining.
So if I tried an inside acme thread it'd probably be a day
or 2 project for me.

Wayne D.

3 TPI Acme thread
 

On Wed, 01 Oct 2008 15:55:31 -0500, Wayne
wrote:

F. George McDuffee was thinking very hard :
On Mon, 29 Sep 2008 17:34:30 -0500, Wayne
wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

==========
It depends on your lathe, and what change gears you have, can buy
or can make. Even with a quick change box you can generally
change some external gears between the spindle and box and get a
whole other range of threads.

Bear in mind that your thread dial may not work with the new
gears and you will have to leave the half nut engaged. Also note
that cutting 3 TPI with a 8 TPI lead screw requires the lead
screw revolve about 3 times [8/3s] faster than the spindle and
this can be a considerable load/strain on the gear train. Some
of the old old lathes had a set up to drive the lead screw to
reduce the strain for very course pitch threads. Acme threads
are tough anyhow so take it easy.

A good reference is http://lindsaybks.com/bks7/sscut/index.html @
$4.95

Let the group know how your make out and good luck.


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

Thanks for the input. Everything I do seems to take a long time.
I have started experimenting taking bigger cuts, but still am
conservative. I'd never make it in the real world of machining.
So if I tried an inside acme thread it'd probably be a day
or 2 project for me.

Wayne D.

==========
Although considered an obsolete accessory, a lathe spindle hand
crank is almost a necessity for this type of project.
see
http://mcduffee-associates.us/machin...ndle_crank.htm

Also be reminded that if this is indeed a metric screw both
metric Acme [29 degree included thread angles] and metric
trapezoidal threads [30 degree include thread angle] exist.

Good luck and let the group know what you find out and how you
make out.


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

3 TPI Acme thread
 

On Wed, 01 Oct 2008 15:46:25 -0500, Wayne
wrote:

used his keyboard to write :
On Sep 29, 7:54 pm, "Pete C." wrote:
"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?
Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

How about casting a new nut from moglice, babbitt, zamak, etc. using
the unworn (less worn) section of the existing screw as the core for
the mold?

Wolfgang

I think I've heard about that stuff on RCM occasionally. I really don't
know anything about them.

Wayne D.

=========
for babbitt information see
http://lindsaybks.com/dgjp/djgbk/babbitt/index.html
http://lindsaybks.com/bks7/babb/index.html
http://lindsaybks.com/bks4/babbitt/index.html

These books cover cast in place nuts, babbitt lathe half nuts and
babbitt tips for travely/steady rests.


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

3 TPI Acme thread
 

Wayne wrote:

Pete C. formulated the question :
"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?

Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

Could be metric since I think he said it came from the old country.
He does have another one, so maybe it isn't all that important for him
to get it fixed. All I hear is it's too heavy. A mill or lathe is
heavy.

If the 1.25" or so acme screw is doing the pressing part, I can't
imagine the whole thing being more than a couple hundred pounds, what
I'd consider pretty light.


I missed that Enco had acme rods/nuts. Mcmaster's prices would put a
repair at about half the cost of the unit. Enco's prices would be
feasible.

Yes, the Enco 1.25x5 was ~$30 for a 3' length.


I didn't even know about multi lead screws until I researched
a mini acme rod for a small stepper motor. Wasn't an even number
of TPI. If you look on the end, do you see 2 starting points?
What's the purpose of them?

I'm not real sure the advantage of multi lead, but they do exist, and
yes looking at the end you do see the multiple starts. I seem to recall
that the TPI number counts all the leads, so the turns per inch is the
threads per inch divided by the starts.

3 TPI Acme thread
 

On Oct 1, 7:39 pm, F. George McDuffee gmcduf...@mcduffee-
associates.us wrote:
On Wed, 01 Oct 2008 15:46:25 -0500, Wayne



wrote:
used his keyboard to write :
On Sep 29, 7:54 pm, "Pete C." wrote:
"Pete C." wrote:

Wayne wrote:

A friend at work has a wine press which needs some help. The internal
threads of a piece that moves up and down on an acme thread are
damaged.
I've been unsuccesful at getting him to bring it so I can measure it.
Through other methods it appears to be 1.25 x 3 TPI (or possibly
M32 x 8.5). I haven't been able to find any sources for any acme
nuts of that size. The lowest the my lathe will go is to 4 TPI.
It will also do 6 or 9 TPI.
Is there anyway to fudge a 3 TPI?

Wayne D.

I suspect it may be metric since it seems that a lot of that type of
equipment comes from metric countries. If he won't bring it for proper
measurement, it can't be all that important to repair eh?
Can you change both pieces so you can use something like the 1.25x5 that
Enco carries? Convert to pneumatic or hydraulic?

Come to think of it, are you sure it isn't a dual/multi lead screw?

How about casting a new nut from moglice, babbitt, zamak, etc. using
the unworn (less worn) section of the existing screw as the core for
the mold?

Wolfgang

I think I've heard about that stuff on RCM occasionally. I really don't
know anything about them.

Wayne D.

=========
for babbitt information seehttp://lindsaybks.com/dgjp/djgbk/babbitt/index.htmlhttp://lindsaybks.com/bks7/babb/index.htmlhttp://lindsaybks.com/bks4/babbitt/index.html

These books cover cast in place nuts, babbitt lathe half nuts and
babbitt tips for travely/steady rests.

Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).


During the last few years an article was published in Home Shop
Machinist that described the casting of a new feed nut using the
commercial epoxy-like material MOGLICE. The author swore by this
stuff (not at it!) while commenting that it was fairly expensive.

I'd be inclined to try a filled epoxy to which I'd added some teflon
powder.

Wolfgang

3 TPI Acme thread
 

On 2008-10-02, Pete C. wrote:

Wayne wrote:

Pete C. formulated the question :

[ ... ]

Come to think of it, are you sure it isn't a dual/multi lead screw?

[ ... ]

I didn't even know about multi lead screws until I researched
a mini acme rod for a small stepper motor. Wasn't an even number
of TPI. If you look on the end, do you see 2 starting points?
What's the purpose of them?

I'm not real sure the advantage of multi lead, but they do exist,

The advantage is that you get more motion per turn.

The disadvantage is that you don't get as much force
multiplication.

The reason to use a multi-lead thread in place of a coarser
standard thread is that you don't have to cut as deep into the rod (thus
weakening it) -- the threads are shallower for the travel per turn.

The primary example that I have here of multi-lead thread (three
starts) is the leadscrew used to raise and lower my garage door. (Hmm
.... another advantage is that it provides three locations in which you
can snap the nut back into engagement after disengaging it for manual
motion of the door. With a coarse single-start thread (which would
require a larger diameter shaft and a larger aluminum extrusion in which
the shaft moves) you would probably have to jiggle the door up or down a
little to get it to snap into engagement.

and
yes looking at the end you do see the multiple starts. I seem to recall
that the TPI number counts all the leads, so the turns per inch is the
threads per inch divided by the starts.

That sounds reasonable -- though I think the term fro the
latter is "the lead".

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

3 TPI Acme thread
 

On 2 Oct 2008 02:09:04 GMT, "DoN. Nichols"
wrote:

On 2008-10-02, Pete C. wrote:

Wayne wrote:

Pete C. formulated the question :

[ ... ]

Come to think of it, are you sure it isn't a dual/multi lead screw?

[ ... ]

I didn't even know about multi lead screws until I researched
a mini acme rod for a small stepper motor. Wasn't an even number
of TPI. If you look on the end, do you see 2 starting points?
What's the purpose of them?

I'm not real sure the advantage of multi lead, but they do exist,

The advantage is that you get more motion per turn.

The disadvantage is that you don't get as much force
multiplication.

The reason to use a multi-lead thread in place of a coarser
standard thread is that you don't have to cut as deep into the rod (thus
weakening it) -- the threads are shallower for the travel per turn.


Another advantage is that a multi-start thread on a small diameter is
more efficient than a single start of equal lead on a diameter large
enough to comfortably accommodate the deeper thread. More efficient
because of the larger helix angle.

--
Ned Simmons

3 TPI Acme thread
 

On Wed, 01 Oct 2008 20:13:00 -0500, "Pete C."
wrote:


Wayne wrote:
snip

I'm not real sure the advantage of multi lead, but they do exist, and
yes looking at the end you do see the multiple starts. I seem to recall
that the TPI number counts all the leads, so the turns per inch is the
threads per inch divided by the starts.

They're commonly used on fly presses, even 3 and 4 start, to get the
downward speed for the strike.

Pete Keillor