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Re: Does anyone make new thread guides for the db /sl?

 

Back in about the year 2000 my dad gave me a complete Unimat DB200 he was given by a man who had purchased it new. The man had a terminal illness and knew my dad was a machinist and wanted it to go to someone who would appreciate it.
Some years later after my dad passed away I was cleaning out his shop and came upon several small boxes, each with individual threaded items in them. I had no idea what they were and tossed them into the trash. They were unused in original boxes.
I could still kick myself to this day.
Re: Does anyone make new thread guides for the db /sl?

 

Tim

Metric threads are 60 degrees, the 55degree masters are Whitworth.

Michael

On Thu, Mar 2, 2023 at 12:55 PM, OldToolmaker wrote:
Tim,
The Unimat thread masters I have had were not buttress thread form but ¡°V¡± form. I would assume the metric thread masters are 55 degree thread form but I am not sure and the US version is most likely UNF 60 degree (unified national fine).
Perhaps someone here on this group can clarify this
.
Re: Does anyone make new thread guides for the db /sl?

 

On Wed, Mar 1, 2023 at 10:17 PM, vt_biketim wrote:
Were they hardened? More to the point, since the followers are brass, can you get away with not hard? And are they cut with a buttress thread form? I've never actually seen a threading attachment.
If the master is made of a decent steel, and the follower brass, they will be OK without hardening. The amount of force on them and the hours of use will be so little that they will be fine. The main thing is to get a decent smooth finish on the master.

All the pictures I've seen - including the one just posted clearly show a "normal" thread, probably 60¡ã. Again the forces don't need anything heftier.
Re: Does anyone make new thread guides for the db /sl?

 

They look simple enough to be 3D printed. I dont think there is much force on them. I could be wrong.
I dont have the dimensions so i'M at a lose to make them. There must be an Sl owner who 3d prints try it.
Dig out your old clock wheels.

 

?

A nice little gem from the past:


DW
Re: Does anyone make new thread guides for the db /sl?

 

¿ªÔÆÌåÓý

The glove box latch on my ¡®65 Lotus Elan is 3/4 x 27

Best Regards
John



On Mar 1, 2023, at 9:29 PM, Jkle379184 via groups.io <jkle379184@...> wrote:

?
?I just checked my Unimat SL masters and followers set and these are the ones that I have for inch and Whitworth.
13, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 36, 40, 48, 50, 56 TPI
Some of these are not listed in the unimat catalogs.
?Jeff


-----Original Message-----
From: Jkle379184 via groups.io <jkle379184@...>
To: [email protected] <[email protected]>
Sent: Wed, Mar 1, 2023 5:28 pm
Subject: Re: [Unimat] Does anyone make new thread guides for the db /sl?

1/4" x 27 TPI was used on old electric lamps for brass parts. There are a lot of "odd" ones out there.
?Jeff


-----Original Message-----
From: vt_biketim <tchock59@...>
To: John Entwistle <jentwistle3@...>; [email protected]
Sent: Wed, Mar 1, 2023 4:52 pm
Subject: Re: [Unimat] Does anyone make new thread guides for the db /sl?

This has piqued my curiosity¡ªwhat equipment used 27tpi? It must have been common enough somewhere b/c I just googled it and found it's stupid easy to get 3/4-27tpi taps and dies. Not even that dear, really, the tap is under $25.

Tim in VT

Re: Does anyone make new thread guides for the db /sl?

 

Hello Bill,
I just found my information on the Atlas 6¡± lathe and it also shows 27 TPI as standard.

I am know my 7x16 MicroMark minilathe can also be configured to cut 27 TPI. I have the mathematical formula to calculate the gear tooth requirements for any thread. Very handy to have.
Re: Does anyone make new thread guides for the db /sl?

 

?I just checked my Unimat SL masters and followers set and these are the ones that I have for inch and Whitworth.
13, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 36, 40, 48, 50, 56 TPI
Some of these are not listed in the unimat catalogs.
?Jeff


-----Original Message-----
From: Jkle379184 via groups.io <jkle379184@...>
To: [email protected] <[email protected]>
Sent: Wed, Mar 1, 2023 5:28 pm
Subject: Re: [Unimat] Does anyone make new thread guides for the db /sl?

1/4" x 27 TPI was used on old electric lamps for brass parts. There are a lot of "odd" ones out there.
?Jeff


-----Original Message-----
From: vt_biketim <tchock59@...>
To: John Entwistle <jentwistle3@...>; [email protected]
Sent: Wed, Mar 1, 2023 4:52 pm
Subject: Re: [Unimat] Does anyone make new thread guides for the db /sl?

This has piqued my curiosity¡ªwhat equipment used 27tpi? It must have been common enough somewhere b/c I just googled it and found it's stupid easy to get 3/4-27tpi taps and dies. Not even that dear, really, the tap is under $25.

Tim in VT

Re: Does anyone make new thread guides for the db /sl?

 

Tim,
The Unimat thread masters I have had were not buttress thread form but ¡°V¡± form. I would assume the metric thread masters are 55 degree thread form but I am not sure and the US version is most likely UNF 60 degree (unified national fine).
Perhaps someone here on this group can clarify this
.
Re: Does anyone make new thread guides for the db /sl?

 

I think uncommon TPI configuration(s) were done on purpose to keep the rookies (like me) from trying my own repairs.

This is an interesting thread though.... couldn't resist.

Speaking of rookies, this one generates for g-code, I don't have a CNC lathe.... (still.)
https://sct-usa.com/thread-mill-code-generator/

Tamra
Re: Does anyone make new thread guides for the db /sl?

 

1/4" x 27 TPI was used on old electric lamps for brass parts. There are a lot of "odd" ones out there.
?Jeff


-----Original Message-----
From: vt_biketim <tchock59@...>
To: John Entwistle <jentwistle3@...>; [email protected]
Sent: Wed, Mar 1, 2023 4:52 pm
Subject: Re: [Unimat] Does anyone make new thread guides for the db /sl?

This has piqued my curiosity¡ªwhat equipment used 27tpi? It must have been common enough somewhere b/c I just googled it and found it's stupid easy to get 3/4-27tpi taps and dies. Not even that dear, really, the tap is under $25.

Tim in VT

Re: Does anyone make new thread guides for the db /sl?

 

Were they hardened? More to the point, since the followers are brass, can you get away with not hard? And are they cut with a buttress thread form? I've never actually seen a threading attachment.

Tim in VT
Re: Does anyone make new thread guides for the db /sl?

 

I just ran out back to look at my Clausing 4902. It has 27 tpi right on the QCGB. Also 22,23,24,26,28, then jumps to 32. No 25, no 30.?

OTOH, I looked up the Atlas threading supplement and a 10F will do 25,27,and 30. Atlas for the win! But you shouldn't need a 32T gear to do this.?
Re: Does anyone make new thread guides for the db /sl?

 

This has piqued my curiosity¡ªwhat equipment used 27tpi? It must have been common enough somewhere b/c I just googled it and found it's stupid easy to get 3/4-27tpi taps and dies. Not even that dear, really, the tap is under $25.

Tim in VT
Re: Does anyone make new thread guides for the db /sl?

 

I am not going to call an Atlas lathe modern, but the threading chart I just looked at lists 27tpi as a regular thread. I have a need to cut 30tpi threads, and I'm going to need a 2nd 32-tooth gear for it. 3D printed one, can't wait to test and find out! At one time, I also wanted to do a 25tpi thread. Don't recall exactly why, now. That one is not on the chart. Going to have to dig through my threading supplement to see if it has a setup for that one, in case I remember why I wanted it. ;)

Anyone want to send me drawings for the parts needed to do 27tpi threading??

Bill in OKC

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

Aphorisms to live by:
Good judgement comes from experience. Experience comes from bad judgement.?
SEMPER GUMBY!
Improvise, Adapt, and Overcome.
Physics doesn't care about your schedule.
The only reason I know anything is because I've done it wrong enough times to START to know better



On Tuesday, February 28, 2023 at 09:48:44 PM CST, Keith S. Angus <keithsangus@...> wrote:


On Tue, Feb 28, 2023 at 11:06 PM, OldToolmaker wrote:
Given the high price of vintage Unimat thread masters, some thought might have to be given
into machining some thread masters to order.

I'm not sure it would be easy to set up many modern lathes to cut 27 tpi. Not sure about some of the older ones either. I'll have a look at our old (1950s vintage) Cardiff to see if that can do it, and how much hassle it would be.

Re: Does anyone make new thread guides for the db /sl?

 

On Tue, Feb 28, 2023 at 11:06 PM, OldToolmaker wrote:
Given the high price of vintage Unimat thread masters, some thought might have to be given
into machining some thread masters to order.

I'm not sure it would be easy to set up many modern lathes to cut 27 tpi. Not sure about some of the older ones either. I'll have a look at our old (1950s vintage) Cardiff to see if that can do it, and how much hassle it would be.
Re: Does anyone make new thread guides for the db /sl?

 

Given the high price of vintage Unimat thread masters, some thought might have to be given
into machining some thread masters to order.
Re: Three jaws chuck tightening

 

¿ªÔÆÌåÓý

Hi Gang:

In Trade School they recommended facing from the outside to the center. The rationale is if you start in the center and one corner is high, it will be too heavy to finish the cut. Light cuts are the way to go on a Unimat, the parts are small and the cuts are usually short.

Do get the proper Tommy Bars, and keep the cuts light.

Carl.

On 2/28/2023 9:41 AM, quinngolden@... wrote:

Regarding your question about the stock moving in the chuck. ?You should get a proper set of Tommy bars to tighten the chuck as well as cleaning it as others have mentioned. ?Also check your facing tool center height and that the tool is sharp.?

Re: Three jaws chuck tightening

 

Regarding your question about the stock moving in the chuck. ?You should get a proper set of Tommy bars to tighten the chuck as well as cleaning it as others have mentioned. ?Also check your facing tool center height and that the tool is sharp.?
Re: Does anyone make new thread guides for the db /sl?

 

¿ªÔÆÌåÓý

Interesting¡­ thanks!

Best Regards
John



On Feb 27, 2023, at 9:48 PM, OldToolmaker via groups.io <old_toolmaker@...> wrote:

?Hello John,

If 27 TPI thread guide are not available for the Unimat SL I can think of at least two ways to make a thread master to fit the SL.
(1) If you have access to a thread cutting lathe you can make an exact copy that will mount right on your SL. This would be my preference.
(2) You can buy a 1/8-27 straight pipe nipple from a hardware store and use it as a master. These can be purchased in fairly long lengths and they are often used in lamps. Of course, you will still need to make a follower to mesh with the master. A 1/8¡±-27 pipe fitting could be pressed into service for this.

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