Date   

parts wanted

Richard Pender
 


--
Hello,
I am UK based and own a 1937 South Bend "modelR" bench lathe (none operational) and am seeking a cross slide, cross slide nut, tapered gibb & screw, associated swarf guard and drive belt tensioning toggle linkage.  I understand that the 9" swing model R is comparitivley rare, but the more common "Heavy Ten" lathe may have components the same as my machine.  It is a long sad story as to how I came to loose these vital parts owing to the death  of the engineer who was to supply modifications to them.  As I have spent a considerable sum both in time and money so far in the refurbishment of this machine
(including having the 84 year old bed ground true), I am understandably very reluctant to part from what currently ammounts to an expensive collection of scrap iron!
Is there anyone who may be able to advise me what to do? (The current owners of the South Bend brand name were no help at all- despite the historicaly based bragging on their web site!
Kind regards
Richard Pender


Re: SB 9 A Leadscrew Drawing wanted

Sam
 

Thanks yes that's exactly what I had in mind.

I'll look this over and digest it.


On Mon, Sep 20, 2021 at 2:33 PM Steve Wells <wswells@...> wrote:

There’s an error in size on the keyway shaft, where it says 0.645, that should be 0.6245…sorry

 

Steve

 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of Steve Wells
Sent: Monday, September 20, 2021 2:26 PM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] SB 9 A Leadscrew Drawing wanted

 

Sam, If I understand correctly, you want to convert your Model B Leadscrew to a Model A.

 

A gear box thrust collar is required on the Model A screw.

 

1.125 OD x 0.750 ID x  0.750 length.

 

first check you screw lengths to make sure this modification will work with your gearbox, and rear mount.

 

Before you position the thrust collar, mark from the left edge of the relief cut for the lead screw acme threads, towards the threaded end of the shaft (left) 4.9375 inches.

 

Cut off the B screw at that measurement.

Now working left to right, mark 0.7031, cut a 0.125 width thread relief on the left side of this mark to .0375 OD. Now you have the new Model A lead screw retaining thread area, turn this area to 0.495.

Thread to 1/2 -13.

 

From the right side of the above thread relief, mark 0.4688, cut a turning relief on the left side of this mark, 0.0625 width, to 0.6094 OD. Turn the marked shaft area between the thread relief and the turning relief area to 0.645 OD.

 

From the right side of the turning relief, mark 1.501, this is the left side front of the thrust collar position. Position and fixture your thrust collar to the left of this mark to allow for the collar to be faced square to the leadscrew (0.010-0.015) or so. Face the collar after fixturing, back to 1.501 again.

 

Set up and mill the keyway for the 3/16 x 3/16 x 7/16 drive key from the turning relief, left to end of the threads, chase the threads and chamfer the end 1/32.

 

Drill and pin the Thrust collar.

 

Photo attached,

 

Hope that helps,

 

Steve

 

 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of Sam
Sent: Sunday, September 19, 2021 10:40 PM
To: SouthBendLathe@groups.io
Subject: [SouthBendLathe] SB 9 A Leadscrew Drawing wanted

 

SB 9 A  Lead-screw Drawing wanted

Does anyone have a drawing for a 9A leadscrew ?

The end that mates with the gearbox is the problem.

I'm looking at  B to A conversion and have no idea how it's supposed to be


Re: SB 9 A Leadscrew Drawing wanted

Steve Wells
 

There’s an error in size on the keyway shaft, where it says 0.645, that should be 0.6245…sorry

 

Steve

 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of Steve Wells
Sent: Monday, September 20, 2021 2:26 PM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] SB 9 A Leadscrew Drawing wanted

 

Sam, If I understand correctly, you want to convert your Model B Leadscrew to a Model A.

 

A gear box thrust collar is required on the Model A screw.

 

1.125 OD x 0.750 ID x  0.750 length.

 

first check you screw lengths to make sure this modification will work with your gearbox, and rear mount.

 

Before you position the thrust collar, mark from the left edge of the relief cut for the lead screw acme threads, towards the threaded end of the shaft (left) 4.9375 inches.

 

Cut off the B screw at that measurement.

Now working left to right, mark 0.7031, cut a 0.125 width thread relief on the left side of this mark to .0375 OD. Now you have the new Model A lead screw retaining thread area, turn this area to 0.495.

Thread to 1/2 -13.

 

From the right side of the above thread relief, mark 0.4688, cut a turning relief on the left side of this mark, 0.0625 width, to 0.6094 OD. Turn the marked shaft area between the thread relief and the turning relief area to 0.645 OD.

 

From the right side of the turning relief, mark 1.501, this is the left side front of the thrust collar position. Position and fixture your thrust collar to the left of this mark to allow for the collar to be faced square to the leadscrew (0.010-0.015) or so. Face the collar after fixturing, back to 1.501 again.

 

Set up and mill the keyway for the 3/16 x 3/16 x 7/16 drive key from the turning relief, left to end of the threads, chase the threads and chamfer the end 1/32.

 

Drill and pin the Thrust collar.

 

Photo attached,

 

Hope that helps,

 

Steve

 

 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of Sam
Sent: Sunday, September 19, 2021 10:40 PM
To: SouthBendLathe@groups.io
Subject: [SouthBendLathe] SB 9 A Leadscrew Drawing wanted

 

SB 9 A  Lead-screw Drawing wanted

Does anyone have a drawing for a 9A leadscrew ?

The end that mates with the gearbox is the problem.

I'm looking at  B to A conversion and have no idea how it's supposed to be


Re: SB 9 A Leadscrew Drawing wanted

Steve Wells
 

Sam, If I understand correctly, you want to convert your Model B Leadscrew to a Model A.

 

A gear box thrust collar is required on the Model A screw.

 

1.125 OD x 0.750 ID x  0.750 length.

 

first check you screw lengths to make sure this modification will work with your gearbox, and rear mount.

 

Before you position the thrust collar, mark from the left edge of the relief cut for the lead screw acme threads, towards the threaded end of the shaft (left) 4.9375 inches.

 

Cut off the B screw at that measurement.

Now working left to right, mark 0.7031, cut a 0.125 width thread relief on the left side of this mark to .0375 OD. Now you have the new Model A lead screw retaining thread area, turn this area to 0.495.

Thread to 1/2 -13.

 

From the right side of the above thread relief, mark 0.4688, cut a turning relief on the left side of this mark, 0.0625 width, to 0.6094 OD. Turn the marked shaft area between the thread relief and the turning relief area to 0.645 OD.

 

From the right side of the turning relief, mark 1.501, this is the left side front of the thrust collar position. Position and fixture your thrust collar to the left of this mark to allow for the collar to be faced square to the leadscrew (0.010-0.015) or so. Face the collar after fixturing, back to 1.501 again.

 

Set up and mill the keyway for the 3/16 x 3/16 x 7/16 drive key from the turning relief, left to end of the threads, chase the threads and chamfer the end 1/32.

 

Drill and pin the Thrust collar.

 

Photo attached,

 

Hope that helps,

 

Steve

 

 

From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> On Behalf Of Sam
Sent: Sunday, September 19, 2021 10:40 PM
To: SouthBendLathe@groups.io
Subject: [SouthBendLathe] SB 9 A Leadscrew Drawing wanted

 

SB 9 A  Lead-screw Drawing wanted

Does anyone have a drawing for a 9A leadscrew ?

The end that mates with the gearbox is the problem.

I'm looking at  B to A conversion and have no idea how it's supposed to be


SB 9 A Leadscrew Drawing wanted

Sam
 

SB 9 A  Lead-screw Drawing wanted

Does anyone have a drawing for a 9A leadscrew ?

The end that mates with the gearbox is the problem.

I'm looking at  B to A conversion and have no idea how it's supposed to be


Re: Mystery Headstock

Pat Johnson
 

Thanks so much guys. It came as part of a lot so I’ve put it on eBay in the U.K. and didn’t want to describe it as something it’s not. Think I can confidently change the description now. 

Coincidentally I’m picking up a SB13 tomorrow really looking forward to getting it home. 

Some more photos from the back. 

 


Re: Mystery Headstock

Bill in OKC too
 

Yours doesn't have original sheaves on the countershaft or motor. Headstock is a different model, too, but can't see enough of it for me to tell which one it is. A photo from the opposite side might have a casting number in it.

Bill in OKC <--- not an expert on Atlas or SB lathes, by any means, but have an Atlas 10F TH42 that is usable as soon as I oil it. My SB Heavy 10L needs quite a bit of restoration work, though.

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)




On Sunday, September 19, 2021, 04:02:44 PM CDT, John Amundson via groups.io <flyinga55@...> wrote:


This is my Atlas 10





On Sun, Sep 19, 2021 at 1:18 PM, Pat Johnson
<pj86400@...> wrote:

Hi Gents

Can anybody identify this headstock please? I understand it’s either from a South Bend or an Atlas

If it helps I can get it measured. 


Thanks
Pat



Re: Mystery Headstock

Bill in OKC too
 

Atlas 10" That part number is a dead giveaway, as is the sheave on the countershaft.

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)




On Sunday, September 19, 2021, 03:18:10 PM CDT, Pat Johnson <pj86400@...> wrote:


Hi Gents

Can anybody identify this headstock please? I understand it’s either from a South Bend or an Atlas

If it helps I can get it measured. 


Thanks
Pat



Re: Mystery Headstock

John Amundson
 

This is my Atlas 10





On Sun, Sep 19, 2021 at 1:18 PM, Pat Johnson
<pj86400@...> wrote:

Hi Gents

Can anybody identify this headstock please? I understand it’s either from a South Bend or an Atlas

If it helps I can get it measured. 


Thanks
Pat



Re: Mystery Headstock

George Meinschein
 

Pat,
I'll go with Atlas 10" Model D.


Thanks, George Meinschein 150 Brittany Drive Freehold, NJ 07728 gmeinschein@... Cell#: 732-580-1736

Sent from ProtonMail mobile



-------- Original Message --------
On Sep 19, 2021, 2:57 PM, Pat Johnson < pj86400@...> wrote:

Hi Gents

Can anybody identify this headstock please? I understand it’s either from a South Bend or an Atlas

If it helps I can get it measured. 


Thanks
Pat



--
-George M.


Mystery Headstock

Pat Johnson
 

Hi Gents

Can anybody identify this headstock please? I understand it’s either from a South Bend or an Atlas

If it helps I can get it measured. 


Thanks
Pat



Re: 1-7/8 x 8 backplate for 10R Spindles

v.gearheardt@...
 

sorry,
sold


Re: cut an M1.75 thread

Phillip Rankin
 

GK,
I've never had an opportunity to work with a 9b, or 9c. I'm sure suitable metric thread approximations can be made without the use of a transposing gear, but I have never given it any thoughts. Perhaps someone that is more familiar with 9b, 9c gear trains will chime in. Now that you brought it up I'm a bit interested myself.

Phillip R.


Re: cut an M1.75 thread

Jim_B
 


--

This should help.

Jim B


Re: cut an M1.75 thread

Bill in OKC too
 

Looking good! I just got my Atlas ready to run this morning. Need to lube it properly and it's ready to go. Got the 7x10 set up earlier this week. Need to do the Smithy next, and then it's time to get back to the restoration of my Heavy 10L. Should be easier with all those other lathes working. Would have been easier still if I only had one... but I'm a gllutton for punishment.

I'm working on an internal threading problem for class, and looking forward to the day I can do such things in my home shop.

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)


A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders,
give orders, cooperate, act alone, solve equations, analyze a new
problem, pitch manure, program a computer, cook a tasty meal, fight
efficiently, die gallantly. Specialization is for insects.
LAZARUS LONG (Robert A. Heinlein)




On Saturday, September 18, 2021, 11:22:32 AM CDT, Carl Bukowsky via groups.io <cwbukows@...> wrote:




Sent by my iPhone

On Sep 18, 2021, at 11:19 AM, Carl W Bukowsky <cwbukows@...> wrote:


I just cut my first metric threads (M50-1.5) on my SB 9” Junior Model C.  I used a 3D printed 80/63 compound gear purchased off eBay.  

Important step in the process is to keep the half-nut engaged until you are complete.  That means take a cut, power down (stop at the relief groove), back out the tool, reverse motor back to beginning of thread, reset tool for next cut, rinse and repeat as they say.  

I had not wired the lathe for reverse, so I had to do that for automating the return of the tool. I also cut slow, using the back gears so the tool would coast to a dead stop at the relief groove at the end of the threading cut. 

The project I’m working on is an ER-40 collet holder and I am using a purchased collet nut hence the requirement for metric threading. I wanted to do some metric threading and I bought several other 3D printed gears besides the compound so I can do a reasonable variety of common metric sizes.   That’s all, just wanted to pass on what I experienced and encourage others. Carl

Sent by my iPhone

On Sep 18, 2021, at 8:34 AM, G K via groups.io <bug_hunter2000@...> wrote:


Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;

Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.

If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.


Re: cut an M1.75 thread

Carl Bukowsky
 

Jack, yeah that was a very happy moment. 

I actually practiced, a dress rehearsal of sorts before I cut the real threads, never hurts to avoid the bozo moments as much as possible. 

I got an ER-32 nut with a lot of ER-40 collets I found online.  The seller didn’t know, so I had to buy one for the project. I may make an ER-32 chuck as well, then I’ll have an excuse to get more collets. 

Carl
Sent by my iPhone

On Sep 18, 2021, at 11:25 AM, Jack Dinan <jack@...> wrote:

Carl: Wonderful.  The only metric thread that I’ve ever cut on my SB9 was that M50 and for that exact reason - to house the ER-40 collet holder.

It has been years since I’ve done so, and I’ve forgotten how I chose the gearing; hence the original posting. 

What I do recall is the amazement and thrill when that holder slipped smoothly onto the male thread I cut. 

I don’t believe I’ve had that level of satisfaction since.

I look forward to hearing the shout of joy from you.

phd

On Sep 18, 2021, at 12:19 PM, Carl Bukowsky via groups.io <cwbukows@...> wrote:

I just cut my first metric threads (M50-1.5) on my SB 9” Junior Model C.  I used a 3D printed 80/63 compound gear purchased off eBay.  

Important step in the process is to keep the half-nut engaged until you are complete.  That means take a cut, power down (stop at the relief groove), back out the tool, reverse motor back to beginning of thread, reset tool for next cut, rinse and repeat as they say.  

I had not wired the lathe for reverse, so I had to do that for automating the return of the tool. I also cut slow, using the back gears so the tool would coast to a dead stop at the relief groove at the end of the threading cut. 

The project I’m working on is an ER-40 collet holder and I am using a purchased collet nut hence the requirement for metric threading. I wanted to do some metric threading and I bought several other 3D printed gears besides the compound so I can do a reasonable variety of common metric sizes.   That’s all, just wanted to pass on what I experienced and encourage others. Carl

Sent by my iPhone

On Sep 18, 2021, at 8:34 AM, G K via groups.io <bug_hunter2000@...> wrote:


Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;
Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.
If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.


Re: cut an M1.75 thread

Jack Dinan
 

Carl: Wonderful.  The only metric thread that I’ve ever cut on my SB9 was that M50 and for that exact reason - to house the ER-40 collet holder.

It has been years since I’ve done so, and I’ve forgotten how I chose the gearing; hence the original posting. 

What I do recall is the amazement and thrill when that holder slipped smoothly onto the male thread I cut. 

I don’t believe I’ve had that level of satisfaction since.

I look forward to hearing the shout of joy from you.

phd

On Sep 18, 2021, at 12:19 PM, Carl Bukowsky via groups.io <cwbukows@...> wrote:

I just cut my first metric threads (M50-1.5) on my SB 9” Junior Model C.  I used a 3D printed 80/63 compound gear purchased off eBay.  

Important step in the process is to keep the half-nut engaged until you are complete.  That means take a cut, power down (stop at the relief groove), back out the tool, reverse motor back to beginning of thread, reset tool for next cut, rinse and repeat as they say.  

I had not wired the lathe for reverse, so I had to do that for automating the return of the tool. I also cut slow, using the back gears so the tool would coast to a dead stop at the relief groove at the end of the threading cut. 

The project I’m working on is an ER-40 collet holder and I am using a purchased collet nut hence the requirement for metric threading. I wanted to do some metric threading and I bought several other 3D printed gears besides the compound so I can do a reasonable variety of common metric sizes.   That’s all, just wanted to pass on what I experienced and encourage others. Carl

Sent by my iPhone

On Sep 18, 2021, at 8:34 AM, G K via groups.io <bug_hunter2000@...> wrote:


Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;
Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.
If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.


Re: cut an M1.75 thread

Carl Bukowsky
 



Sent by my iPhone

On Sep 18, 2021, at 11:19 AM, Carl W Bukowsky <cwbukows@...> wrote:

I just cut my first metric threads (M50-1.5) on my SB 9” Junior Model C.  I used a 3D printed 80/63 compound gear purchased off eBay.  

Important step in the process is to keep the half-nut engaged until you are complete.  That means take a cut, power down (stop at the relief groove), back out the tool, reverse motor back to beginning of thread, reset tool for next cut, rinse and repeat as they say.  

I had not wired the lathe for reverse, so I had to do that for automating the return of the tool. I also cut slow, using the back gears so the tool would coast to a dead stop at the relief groove at the end of the threading cut. 

The project I’m working on is an ER-40 collet holder and I am using a purchased collet nut hence the requirement for metric threading. I wanted to do some metric threading and I bought several other 3D printed gears besides the compound so I can do a reasonable variety of common metric sizes.   That’s all, just wanted to pass on what I experienced and encourage others. Carl

Sent by my iPhone

On Sep 18, 2021, at 8:34 AM, G K via groups.io <bug_hunter2000@...> wrote:


Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;

Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.

If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.


Re: cut an M1.75 thread

Carl Bukowsky
 

I just cut my first metric threads (M50-1.5) on my SB 9” Junior Model C.  I used a 3D printed 80/63 compound gear purchased off eBay.  

Important step in the process is to keep the half-nut engaged until you are complete.  That means take a cut, power down (stop at the relief groove), back out the tool, reverse motor back to beginning of thread, reset tool for next cut, rinse and repeat as they say.  

I had not wired the lathe for reverse, so I had to do that for automating the return of the tool. I also cut slow, using the back gears so the tool would coast to a dead stop at the relief groove at the end of the threading cut. 

The project I’m working on is an ER-40 collet holder and I am using a purchased collet nut hence the requirement for metric threading. I wanted to do some metric threading and I bought several other 3D printed gears besides the compound so I can do a reasonable variety of common metric sizes.   That’s all, just wanted to pass on what I experienced and encourage others. Carl

Sent by my iPhone

On Sep 18, 2021, at 8:34 AM, G K via groups.io <bug_hunter2000@...> wrote:


Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;

Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.

If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.


Re: cut an M1.75 thread

G K
 

Any ideas on coordinating this to a 9C (No QCGB)?

No current need, but just a point of discussion.

A great weekend to all!



On Friday, September 17, 2021, 11:36:29 AM CDT, Phillip Rankin <phillip.rankin1964@...> wrote:


Jack;

Several years ago I put together a couple of charts for my own use cutting metric threads. At the time there weren’t any 3d printed transposing gears being offered on eBay, and 127/100 transposing gears for a SB 9a / 10K were out of my price range, so I needed to find combinations of change gears to work with the standard 80 tooth idler gear to render approximate metric threads. I’ve cut everything between, and including 1mm – 2mm thread pitches, and for normal thread engagement lengths these combinations have worked very well, and many are slightly better than what can be achieved if one were to us a 47/37 transposing gear.

I created Chart 1 first, and although it worked I found it somewhat lacking as it didn’t identify all the possibilities with the different gear combinations, so I created the second chart. I like it much better as it gives me a visual similar to the tag on my gearbox.

If one of the group admins could add these charts to the files I would be grateful. I believe they could be a benefit to all.

Phillip R.

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