Date   

how do I clean and polish a lathe bed

Matt R
 

I had started cleaning my 16/24 with a small hand stone. It was working great but the stone quickly abraded away. The finish I got is great. All of the high spots, rust and oil staining were taken care of. What kind of stone did I have? Had it in a drawer forever so I have  no idea what grade or type of stone it was. It was grey and about 6x1x1/4 in dimension.


Re: Major Online Mask Sale With Discount

LarryS <vision1@...>
 

Good move.

He spammed a couple of groups I’m on.

 

L.

 

From: SouthBendLathe@groups.io [mailto:SouthBendLathe@groups.io] On Behalf Of Jim_B
Sent: Tuesday, July 28, 2020 11:31 AM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] Major Online Mask Sale With Discount

 

 

This message has been removed and the member moderated.

 

 

 


--
Jim B


Re: Major Online Mask Sale With Discount

Jim_B
 


This message has been removed and the member moderated.






--
Jim B


Re: TPI discrepancy

Michael R
 

Thanks Davis, that's exactly what happened, I miscounted the crests.
Changing  to a 56t gear did the trick.
My confusion is that the threading chart on the gear box notes the stud gear (gear box gear?) as 40t.


Re: TPI discrepancy

Davis Johnson
 

Correcting myself:

If you lay a rule along a thread with a crest aligned with one inch mark and count crests until you get to the crest aligned with the next inch mark you will get a thread count one too high if you count both crests aligned with inch marks.

On 7/28/20 8:02 AM, Davis Johnson wrote:

I suspect that we are looking at two possible errors that stirred together produce more confusion than either would produce alone.

First, as Ondrej points out, an easy and common error when trying to count TPI with a rule results in a count one too high. If you lay a rule along a thread with a crest aligned with one inch mark and count crests until you get to the crest aligned with the next inch mark you will get a thread count one too high if you count both crests aligned with inch marks. I rather suspect this is what has happened to get 9tpi for the lead screw.

The other problem I rather suspect is that the end gears are set up wrong. If the gear chart specifies a stud gear than I think that implies a double tumbler gear box. The stud gear listed on the gear box goes on the output shaft of the reverse tumbler (on Southbend lathes that have a reverse tumbler). The gear on the input shaft of the gear box isn't usually, in my limited experience, called a stud gear. It is usually a 56 tooth gear.

If a 40 tooth gear is set up on the gearbox input replacing a 56 tooth gear you would get 8*56/40 or 11.2tpi. That wouldn't quite explain it.

On 7/28/20 3:45 AM, Ondrej Krejci via groups.io wrote:
Howdy,

Either someone cannot determine inch pitch or the gear box is metric.  I am betting on the former.

Good Luck,


OK

On Monday, July 27, 2020, 10:39:28 PM EDT, ken campbell <deltainc@...> wrote:


if the upper spindle gear is supposed to be 20 instead of 40 ..... the
thread pitch would be off by 2 - 1 , not 13 per cent.

and a 9-pitch lead screw could only cut a few useful threads.

interesting.




Re: TPI discrepancy

Davis Johnson
 

I suspect that we are looking at two possible errors that stirred together produce more confusion than either would produce alone.

First, as Ondrej points out, an easy and common error when trying to count TPI with a rule results in a count one too high. If you lay a rule along a thread with a crest aligned with one inch mark and count crests until you get to the crest aligned with the next inch mark you will get a thread count one too high unless if you count both crests aligned with inch marks. I rather suspect this is what has happened to get 9tpi for the lead screw.

The other problem I rather suspect is that the end gears are set up wrong. If the gear chart specifies a stud gear than I think that implies a double tumbler gear box. The stud gear listed on the gear box goes on the output shaft of the reverse tumbler (on Southbend lathes that have a reverse tumbler). The gear on the input shaft of the gear box isn't usually, in my limited experience, called a stud gear. It is usually a 56 tooth gear.

If a 40 tooth gear is set up on the gearbox input replacing a 56 tooth gear you would get 8*56/40 or 11.2tpi. That wouldn't quite explain it.

On 7/28/20 3:45 AM, Ondrej Krejci via groups.io wrote:
Howdy,

Either someone cannot determine inch pitch or the gear box is metric.  I am betting on the former.

Good Luck,


OK

On Monday, July 27, 2020, 10:39:28 PM EDT, ken campbell <deltainc@...> wrote:


if the upper spindle gear is supposed to be 20 instead of 40 ..... the
thread pitch would be off by 2 - 1 , not 13 per cent.

and a 9-pitch lead screw could only cut a few useful threads.

interesting.




Re: TPI discrepancy

Ondrej Krejci
 

Howdy,

Either someone cannot determine inch pitch or the gear box is metric.  I am betting on the former.

Good Luck,


OK

On Monday, July 27, 2020, 10:39:28 PM EDT, ken campbell <deltainc@...> wrote:


if the upper spindle gear is supposed to be 20 instead of 40 ..... the
thread pitch would be off by 2 - 1 , not 13 per cent.

and a 9-pitch lead screw could only cut a few useful threads.

interesting.




Re: TPI discrepancy

ken campbell
 

if the upper spindle gear is supposed to be 20 instead of 40 ..... the thread pitch would be off by 2 - 1 , not 13 per cent.

and a 9-pitch lead screw could only cut a few useful threads.

interesting.


Re: TPI discrepancy

Phillip Rankin
 

Michael;
It would be helpful to know what model lathe you are using. The gear train on a model 9 inch isn't the same as the gear train on a 13 inch model.

P. Rankin


Re: South Bend Model "N" Owners - Resources

mike allen
 

        thanks for the info !

        animal

On 7/26/2020 3:26 PM, m. allan noah wrote:
AFAIK, the bed and headstock on a series N is the same as a series O. The difference is entirely in the apron.

On Sun, Jul 26, 2020, 10:55 AM david_g4000 via groups.io <dmbanwarth=verizon.net@groups.io> wrote:
Animal,

There is some interesting history being posted in this thread. To
summarize some of it - It was a short production period for this higher
priced model, due to the economic times of the 1930's. The N was a high
precision "tool room" class lathe with a heavy headstock construction
and wide ways, among other features, that increased the cost to produce.
Also, the double tumbler feature came along in subsequent models. Some
of the controls are rather unique as well. Also, the apron design. I am
enjoying the contributions from many on this topic.

Dave

On 7/25/2020 7:49 PM, mike allen wrote:
> yea , I'm interested in learnin what the difference is between a type
> N & the other lathes
>
> ��� ��� animal
>
> On 7/25/2020 7:57 AM, m. allan noah wrote:
>> I've never used a Series N power feeds- how is it that the leadscrew
>> reverse tumbler direction controls facing vs turning?
>>
>> allan
>>


Re: South Bend Model "N" Owners - Resources

david_g4000
 

Allan,

I see the differences now in the headstock design and the bed between the N and O series.

According to the SB Bulletins for each:

1. both headstocks were "internally webbed" for added strength and rigidity.

2. the N was provided a "hardened and ground spindle" with a choice of bearings, whereas the O was provided with a "special alloy spindle steel"

3. the lathe beds on the N series were provided with a "new semi-steel mixture containing 50% steel".� Whereas the O series were provided with "cast iron, containing 50% steel."

I could not compare the way dimensions, but the materials were different between the two. As you pointed out the aprons were different as well.

Thanks,

Dave


On 7/26/2020 6:26 PM, m. allan noah wrote:
AFAIK, the bed and headstock on a series N is the same as a series O. The difference is entirely in the apron.

On Sun, Jul 26, 2020, 10:55 AM david_g4000 via groups.io <dmbanwarth=verizon.net@groups.io> wrote:
Animal,

There is some interesting history being posted in this thread. To
summarize some of it - It was a short production period for this higher
priced model, due to the economic times of the 1930's. The N was a high
precision "tool room" class lathe with a heavy headstock construction
and wide ways, among other features, that increased the cost to produce.
Also, the double tumbler feature came along in subsequent models. Some
of the controls are rather unique as well. Also, the apron design. I am
enjoying the contributions from many on this topic.

Dave

On 7/25/2020 7:49 PM, mike allen wrote:
> yea , I'm interested in learnin what the difference is between a type
> N & the other lathes
>
> ��� ��� animal
>
> On 7/25/2020 7:57 AM, m. allan noah wrote:
>> I've never used a Series N power feeds- how is it that the leadscrew
>> reverse tumbler direction controls facing vs turning?
>>
>> allan
>>
>> On Sat, Jul 25, 2020 at 10:52 AM david_g4000 via groups.io
>> <dmbanwarth=verizon.net@groups.io> wrote:
>>> That was the problem I was having too. Glad it is helpful Dan. If
>>> you see any updates needed, please let me know.
>>>
>>> -------- Original message --------
>>> From: Dan Beeker <debeeker@...>
>>> Date: 7/25/20 10:21 AM (GMT-05:00)
>>> To: SouthBendLathe@groups.io
>>> Subject: Re: [SouthBendLathe] South Bend Model "N" Owners - Resources
>>>
>>> What a great resource. I use my 16�� Type N South Bend just often
>>> enough to forget how to switch between turning and threading. Your
>>> documents will fill a sacred spot on the wall beside my lathe. Thank
>>> you for posting the instructions.
>>>
>>>
>>>
>>> Dan Beeker
>>>
>>>
>>>
>>> PureUnobtanium.com
>>>
>>> Indiana University - retired
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>




Re: South Bend Model "N" Owners - Resources

david_g4000
 

Thanks Allan. Seems I need to do some research.

Dave

On 7/26/2020 6:26 PM, m. allan noah wrote:
AFAIK, the bed and headstock on a series N is the same as a series O. The difference is entirely in the apron.

On Sun, Jul 26, 2020, 10:55 AM david_g4000 via groups.io <dmbanwarth=verizon.net@groups.io> wrote:
Animal,

There is some interesting history being posted in this thread. To
summarize some of it - It was a short production period for this higher
priced model, due to the economic times of the 1930's. The N was a high
precision "tool room" class lathe with a heavy headstock construction
and wide ways, among other features, that increased the cost to produce.
Also, the double tumbler feature came along in subsequent models. Some
of the controls are rather unique as well. Also, the apron design. I am
enjoying the contributions from many on this topic.

Dave

On 7/25/2020 7:49 PM, mike allen wrote:
> yea , I'm interested in learnin what the difference is between a type
> N & the other lathes
>
> ��� ��� animal
>
> On 7/25/2020 7:57 AM, m. allan noah wrote:
>> I've never used a Series N power feeds- how is it that the leadscrew
>> reverse tumbler direction controls facing vs turning?
>>
>> allan
>>
>> On Sat, Jul 25, 2020 at 10:52 AM david_g4000 via groups.io
>> <dmbanwarth=verizon.net@groups.io> wrote:
>>> That was the problem I was having too. Glad it is helpful Dan. If
>>> you see any updates needed, please let me know.
>>>
>>> -------- Original message --------
>>> From: Dan Beeker <debeeker@...>
>>> Date: 7/25/20 10:21 AM (GMT-05:00)
>>> To: SouthBendLathe@groups.io
>>> Subject: Re: [SouthBendLathe] South Bend Model "N" Owners - Resources
>>>
>>> What a great resource. I use my 16�� Type N South Bend just often
>>> enough to forget how to switch between turning and threading. Your
>>> documents will fill a sacred spot on the wall beside my lathe. Thank
>>> you for posting the instructions.
>>>
>>>
>>>
>>> Dan Beeker
>>>
>>>
>>>
>>> PureUnobtanium.com
>>>
>>> Indiana University - retired
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>




Re: South Bend Model "N" Owners - Resources

m. allan noah
 

AFAIK, the bed and headstock on a series N is the same as a series O. The difference is entirely in the apron.


On Sun, Jul 26, 2020, 10:55 AM david_g4000 via groups.io <dmbanwarth=verizon.net@groups.io> wrote:
Animal,

There is some interesting history being posted in this thread. To
summarize some of it - It was a short production period for this higher
priced model, due to the economic times of the 1930's. The N was a high
precision "tool room" class lathe with a heavy headstock construction
and wide ways, among other features, that increased the cost to produce.
Also, the double tumbler feature came along in subsequent models. Some
of the controls are rather unique as well. Also, the apron design. I am
enjoying the contributions from many on this topic.

Dave

On 7/25/2020 7:49 PM, mike allen wrote:
> yea , I'm interested in learnin what the difference is between a type
> N & the other lathes
>
> ��� ��� animal
>
> On 7/25/2020 7:57 AM, m. allan noah wrote:
>> I've never used a Series N power feeds- how is it that the leadscrew
>> reverse tumbler direction controls facing vs turning?
>>
>> allan
>>
>> On Sat, Jul 25, 2020 at 10:52 AM david_g4000 via groups.io
>> <dmbanwarth=verizon.net@groups.io> wrote:
>>> That was the problem I was having too. Glad it is helpful Dan. If
>>> you see any updates needed, please let me know.
>>>
>>> -------- Original message --------
>>> From: Dan Beeker <debeeker@...>
>>> Date: 7/25/20 10:21 AM (GMT-05:00)
>>> To: SouthBendLathe@groups.io
>>> Subject: Re: [SouthBendLathe] South Bend Model "N" Owners - Resources
>>>
>>> What a great resource. I use my 16�� Type N South Bend just often
>>> enough to forget how to switch between turning and threading. Your
>>> documents will fill a sacred spot on the wall beside my lathe. Thank
>>> you for posting the instructions.
>>>
>>>
>>>
>>> Dan Beeker
>>>
>>>
>>>
>>> PureUnobtanium.com
>>>
>>> Indiana University - retired
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>




Re: TPI discrepancy

m. allan noah
 

The leadscrew is 8 too, not 9. The gearbox input gear is 56 tooth, not 40.


On Sun, Jul 26, 2020, 5:42 PM John Dammeyer <johnd@...> wrote:

Threading isn't rocket science.  To me the 9 TPI leadscrew doesn't sound right but I don't know.  Maybe South Bends did come with that.

 

I'd put a dial indicator on the ways and then turn the lead screw by hand one turn with the half nut engaged and the backlash removed by first turning the leadscrew a few turns in the same direction.  If it's 8 TPI it would 0.125". If it's 9 TPI it's 0.11111111111111111111111…" which is not really logical.  Where if 10 TPI it's 0.1  Generally leadscrews are set up to not have infinite repeating decimals.

 

Next forget about the pitch you want and if the leadscrew is really 9 TPI then set up to cut 9 TPI.  Now the lead screw will turn exactly one turn for each turn of the spindle.  If that doesn't work again take a look at the gears.

 

John Dammeyer

 

"ELS! Nothing else works as well for your Lathe"

Automation Artisans Inc.

www dot autoartisans dot com

 

 

 

 

 

From: SouthBendLathe@groups.io [mailto:SouthBendLathe@groups.io] On Behalf Of Michael R via groups.io
Sent: July-26-20 2:31 PM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] TPI discrepancy

 

Yep, using the half nuts for threading.

The gear configuration is as follows:
Top stud gear - 40t (according to my parts manual it should be 20t)
Idler gear - 80t
Stud gear to lead screw - 40t (this is correct as it's indicated on the gearbox thread chart)
Lead screw - 9p

Another issue with this machine is that the longitudinal power feed spins way too fast, not delivering a good finish.

Wondering if the top stud gear could be the culprit for both problems?


Re: TPI discrepancy

John Dammeyer
 

Threading isn't rocket science.  To me the 9 TPI leadscrew doesn't sound right but I don't know.  Maybe South Bends did come with that.

 

I'd put a dial indicator on the ways and then turn the lead screw by hand one turn with the half nut engaged and the backlash removed by first turning the leadscrew a few turns in the same direction.  If it's 8 TPI it would 0.125". If it's 9 TPI it's 0.11111111111111111111111…" which is not really logical.  Where if 10 TPI it's 0.1  Generally leadscrews are set up to not have infinite repeating decimals.

 

Next forget about the pitch you want and if the leadscrew is really 9 TPI then set up to cut 9 TPI.  Now the lead screw will turn exactly one turn for each turn of the spindle.  If that doesn't work again take a look at the gears.

 

John Dammeyer

 

"ELS! Nothing else works as well for your Lathe"

Automation Artisans Inc.

www dot autoartisans dot com

 

 

 

 

 

From: SouthBendLathe@groups.io [mailto:SouthBendLathe@groups.io] On Behalf Of Michael R via groups.io
Sent: July-26-20 2:31 PM
To: SouthBendLathe@groups.io
Subject: Re: [SouthBendLathe] TPI discrepancy

 

Yep, using the half nuts for threading.

The gear configuration is as follows:
Top stud gear - 40t (according to my parts manual it should be 20t)
Idler gear - 80t
Stud gear to lead screw - 40t (this is correct as it's indicated on the gearbox thread chart)
Lead screw - 9p

Another issue with this machine is that the longitudinal power feed spins way too fast, not delivering a good finish.

Wondering if the top stud gear could be the culprit for both problems?


Re: TPI discrepancy

Michael R
 

Yep, using the half nuts for threading.

The gear configuration is as follows:
Top stud gear - 40t (according to my parts manual it should be 20t)
Idler gear - 80t
Stud gear to lead screw - 40t (this is correct as it's indicated on the gearbox thread chart)
Lead screw - 9p

Another issue with this machine is that the longitudinal power feed spins way too fast, not delivering a good finish.

Wondering if the top stud gear could be the culprit for both problems?


Re: TPI discrepancy

glenn brooks <brooks.glenn@...>
 

Hmmm,  you can always cut a test thread and measure the actual pitch with a known gauge.


On Jul 26, 2020, at 12:07 PM, eddie.draper@... via groups.io <eddie.draper@...> wrote:


Oh dear!

Has whoever sold you the lathe kindly supplied a metric transposing gear (127 teeth) in the train under the cover on the left hand side?  Check the tooth counts for all the gears from spindle to gearbox input and see if they match what is in the catalogue.  There might be a listing somewhere in the files section.

I take it your leadscrew has an Imperial rather than metric pitch?  Worth a check.

Eddie

On Sunday, 26 July 2020, 19:46:42 BST, Michael R via groups.io <reflexermr@...> wrote:


I'm threading a backplate for the Jacobs collet chuck. The spindle is 8 tpi. I've checked that the gearbox levers are in the correct position and
did the obligatory scratch pass. The gage shows it closer to a 7 tpi than 8. Any thought as to what would cause this discrepancy?

This is the first time single pointing with this lathe.
Thanks,
Michael


Re: TPI discrepancy

eddie.draper@btinternet.com
 

Oh dear!

Has whoever sold you the lathe kindly supplied a metric transposing gear (127 teeth) in the train under the cover on the left hand side?  Check the tooth counts for all the gears from spindle to gearbox input and see if they match what is in the catalogue.  There might be a listing somewhere in the files section.

I take it your leadscrew has an Imperial rather than metric pitch?  Worth a check.

Eddie

On Sunday, 26 July 2020, 19:46:42 BST, Michael R via groups.io <reflexermr@...> wrote:


I'm threading a backplate for the Jacobs collet chuck. The spindle is 8 tpi. I've checked that the gearbox levers are in the correct position and
did the obligatory scratch pass. The gage shows it closer to a 7 tpi than 8. Any thought as to what would cause this discrepancy?

This is the first time single pointing with this lathe.
Thanks,
Michael


Re: TPI discrepancy

comstock_friend
 
Edited

Correct end gears in the gear train? Using half nuts and not the feed knob/lever?

John


Re: South Bend Model "N" Owners - Resources

comstock_friend
 

Dennis Turk has been playing over on Facebook

John

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