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tea lady
17th May 2009, 05:26 PM
what the thread is on your head stock? I have acquired an old home made lathe from the Knox Woodies. (Ages ago, but here I am finally getting around to getting it set up. :rolleyes: ) Cost me a whole $30. :cool: But how do I work out what the thread is on the Head stock thingy? :blond: so I can get face plates and chucks and stuff onto it? :D

Thanks in advance.:U

Tankstand
17th May 2009, 05:46 PM
Hi,
First you need to measure the width across the threads, (this is made easier with verniers) could be imperial or metric or being home made it could be anything!

Then you need to count how many threads there are, if your diameter was imperial then you count how many threads there are in 1" of length. If the diameter was metric, you count the distance between the threads (counting 10 is easier) Could be any where from 1.5mm up to 3.5mm. Put zero on the first thread, then start counting 10 more, don't count the first one! If you get to 20mm then you have a pitch of 2.0mm.

My old woodfast is 1" X 10 TPI for example.

Hope this makes sense and hasn't confused you.

Skew ChiDAMN!!
17th May 2009, 05:48 PM
Here's a "how-to" and a table of many common threads:

How to ID your lathe thread (http://www.teknatool.com/support/how%20to%20id%20your%20lathe%20thread.htm)

tea lady
17th May 2009, 05:56 PM
Hi,
First you need to measure the width across the threads, (this is made easier with verniers) could be imperial or metric or being home made it could be anything!

Then you need to count how many threads there are, if your diameter was imperial then you count how many threads there are in 1" of length. If the diameter was metric, you count the distance between the threads (counting 10 is easier) Could be any where from 1.5mm up to 3.5mm. Put zero on the first thread, then start counting 10 more, don't count the first one! If you get to 20mm then you have a pitch of 2.0mm.

My old woodfast is 1" X 10 TPI for example.

Hope this makes sense and hasn't confused you.

How do you know just from measuring if it is imperial or metric? :dunce:

tea lady
17th May 2009, 06:13 PM
It appears to be 1" 8TPI.:cool: Well! That was easy. Its even on the list.:2tsup: (Although I have 1" 10 threads on chucks and stuff at the moment.:doh: )

Tankstand
17th May 2009, 06:15 PM
It comes down to the measurement you get and seeing how close it is to being an Imperial or Metric whole number.

Threads are usually made to whole increments I.E. A one inch thread measures 25.4mm, no common metric equivalent normally the closest thread is 24mm then 27mm.

when it comes to 3/4" 19.05mm then it can be confused with 19mm. The Imperial thrad has a much coarser thread than the metric in this instance. I would then reach for my screw pitch gauge (not something the layman usually owns) Metric thread forms are 60 Degrees and usually Imperial is 55 Degrees.(yes there are many forms of imperial)

I'll be interested to know the measurement.

Tankstand
17th May 2009, 06:19 PM
It appears to be 1" 8TPI.:cool: Well! That was easy.

Well done!

Too easy.

Manuka Jock
17th May 2009, 06:21 PM
It appears to be 1" 8TPI.:cool: Well! That was easy. Its even on the list.:2tsup: (Although I have 1" 10 threads on chucks and stuff at the moment.:doh: )

TL , what make of chucks are they ?

tea lady
17th May 2009, 06:25 PM
TL , what make of chucks are they ? Its alright. They have inserts in then that I can change. (I think the chuck was an old Nova or something. :think: ) Don't ask me the make of the face plate. :shrug: Got it from Jim.:cool:

tea lady
17th May 2009, 06:26 PM
Here's a "how-to" and a table of many common threads:

How to ID your lathe thread (http://www.teknatool.com/support/how%20to%20id%20your%20lathe%20thread.htm)
Ta muchly! :2tsup:

Manuka Jock
17th May 2009, 06:29 PM
Its alright. They have inserts in then that I can change. (I think the chuck was an old Nova or something. :think: ) Don't ask me the make of the face plate. :shrug: Got it from Jim.:cool:

Ok , all good then huh .

tea lady
17th May 2009, 11:49 PM
So, Jim Carrol, expect a call tommorow arvo.:D

joe greiner
18th May 2009, 12:11 AM
It comes down to the measurement you get and seeing how close it is to being an Imperial or Metric whole number.

Threads are usually made to whole increments I.E. A one inch thread measures 25.4mm, no common metric equivalent normally the closest thread is 24mm then 27mm.

when it comes to 3/4" 19.05mm then it can be confused with 19mm. The Imperial thrad has a much coarser thread than the metric in this instance. I would then reach for my screw pitch gauge (not something the layman usually owns) Metric thread forms are 60 Degrees and usually Imperial is 55 Degrees.(yes there are many forms of imperial)

I'll be interested to know the measurement.
Almost right.

There is no shortage of nonsense regarding screw thread systems, and entire books have been written about them. Skew's link provides most of the accurate information. Note in particular, that 60 degrees is standard for both Imperial and metric. 55 degrees is standard for Whitworth (the old British system). Acme and buttress threads are other variations.

A complexifying factor (for want of a better term) is that all thread systems contain "classes of fit," embodying admissible gaps for purpose of assembly, or deliberate interference for resistance to auto-disengagement, e.g. due to vibration. Because of this, it may nonetheless be possible to assemble components which should not be compatible; but the strength of such assembly is unreliable.

Use Skew's link. It's on the Internet, so you know it must be true.:wink::D

Cheers,
Joe

tea lady
18th May 2009, 09:57 AM
Uuuuuuuuuuuuuuuuuum! Thanks joe. The more info the better. I'll go to a nut and bolt shop today an dget a 1" 8 nut to make sure it goes on.:cool:

Woodwould
18th May 2009, 12:02 PM
Depending on how well the threads have been formed on your lathe, you might be advised to purchase a 1- 8 BSW and a 1- 8 UNC nut. Although they're both 1" - 8TPI, the thread forms are different.

tea lady
18th May 2009, 02:35 PM
Well. I get my 1"8 nut. it fits, but I don't know if its BSW or UNC.:doh: Didn't ask me about that. :shrug: (So whats the difference between them again.:C )

Skew ChiDAMN!!
18th May 2009, 06:34 PM
You buying the adapter from Jim Carroll?

What's the betting that, if you tell him the make/model of lathe, he'll know which adaptor to send? :U

Grumpy John
18th May 2009, 06:46 PM
Remember, you asked for this Anne-Maria :D.


105548

P = Pitch = Dimension in millimeters
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105549

P = Pitch = 1/Number of threads per inch (tpi)
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105550

P = Pitch = 1/Number of threads per inch (tpi)
h = Angular Depth = 0.960491 x P
D = Depth of Rounding = 0.073917 x P
h/6 = Shortening = 0.160083 x P
d = Actual Depth = 0.640327 x P
r = Radius at the Crest & Root = 0.137329 x P
C = Core diameter = Major Diameter - 1.280654 x P
Effective or Pitch Diameter = Major Diameter - .640327 x P

You could always get yourself one of these (http://www.axminster.co.uk/showimage.asp?pf_id=20633&image=images/products/images/products/662422_xl.jpg&title=Zeus+Reference+Book) and make your own adaptors on 's metal cutting lathe :rolleyes:.

Ashore
18th May 2009, 06:49 PM
I have acquired an old home made lathe from the Knox Woodies./quote]

[quote=Skew ChiDAMN!!;957719]You buying the adapter from Jim Carroll?

What's the betting that, if you tell him the make/model of lathe, he'll know which adaptor to send? :U
One small prob skew old home made lathe :D god knows could be anything
TL the diffrence is the angle of the thread one ( Whitworth ) is 55 deg, and UNC is 60 deg:2tsup:

Skew ChiDAMN!!
18th May 2009, 06:51 PM
:doh: Missed that. I need more caffeine...

Another option... spray the thread with WD-40 or light machine oil, get a blob of clay (no shortage of that around there, I suspect :p) and take a cast of half the thread.

Take the cast into the nut'n'bolts supplier and make IDing it their problem. :U

Woodwould
18th May 2009, 07:03 PM
Remember, you asked for this Anne-Maria :D.


105548

P = Pitch = Dimension in millimeters
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105549

P = Pitch = 1/Number of threads per inch (tpi)
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105550

P = Pitch = 1/Number of threads per inch (tpi)
h = Angular Depth = 0.960491 x P
D = Depth of Rounding = 0.073917 x P
h/6 = Shortening = 0.160083 x P
d = Actual Depth = 0.640327 x P
r = Radius at the Crest & Root = 0.137329 x P
C = Core diameter = Major Diameter - 1.280654 x P
Effective or Pitch Diameter = Major Diameter - .640327 x P

You could always get yourself one of these (http://www.axminster.co.uk/showimage.asp?pf_id=20633&image=images/products/images/products/662422_xl.jpg&title=Zeus+Reference+Book) and make your own adaptors on 's metal cutting lathe :rolleyes:.

:U GJ beat me to it. I've got Metric/ISO/Whitworth thread gauges if you want to borrow them for precisely IDing the thread, or do as Skew suggests with the clay.

tea lady
18th May 2009, 08:40 PM
Remember, you asked for this Anne-Maria :D.


105548

P = Pitch = Dimension in millimeters
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105549

P = Pitch = 1/Number of threads per inch (tpi)
H = Angular Depth = 0.866025 x P
H/8 = Shortening of major dia = 0.108253 x P
H/4 = Shortening of minor dia = 0.216506 x P
d = Actual Depth = 0.541266 x P
r = Radius at the Root = 0.1443 x P
Hn = Basic height of Internal Thread = 0.54127 x P
Hs = Basic height of External Thread = 0.61344 x P



105550

P = Pitch = 1/Number of threads per inch (tpi)
h = Angular Depth = 0.960491 x P
D = Depth of Rounding = 0.073917 x P
h/6 = Shortening = 0.160083 x P
d = Actual Depth = 0.640327 x P
r = Radius at the Crest & Root = 0.137329 x P
C = Core diameter = Major Diameter - 1.280654 x P
Effective or Pitch Diameter = Major Diameter - .640327 x P

You could always get yourself one of these (http://www.axminster.co.uk/showimage.asp?pf_id=20633&image=images/products/images/products/662422_xl.jpg&title=Zeus+Reference+Book) and make your own adaptors on 's metal cutting lathe :rolleyes:.

Gee thanks Grumpy..... I think. Think I might leave the adapter making to experts. Ya gotta do a thread on the outside a thread on the inside and have 'em pointing in exactly the same direction. :doh: Which I think might be quite tricky with big thread and diameters. :C Maybe you could show me how Grumps.:D

NeilS
19th May 2009, 04:17 PM
Think I might leave the adapter making to experts.



Smart move TL. I had a one made up by an expert for a thread for which an off-the-shelf adaptor wasn't available and it wasn't true, well not when reversing larger (500mm+) bowls...:( Definitely not worth mucking about with if you don't have to.

Just get a 1"x8tpi adaptor from Jim and see how it goes. As long as you don't use a wrench to get it on your thread I'm sure he would swap/take it back if it doesn't fit.

Neil

tea lady
19th May 2009, 07:34 PM
:cool: Well! My nut fits. :2tsup: Thread adapters are $30. Maybe in next weeks budget. :C

tea lady
28th May 2009, 03:19 PM
Well, I got an insert from a very nice bloke that lives down near the coast. Seems he has everything in that shed. :dunce: The lathe is now bolted to the bench. Chuck is on. It all goes round with no wobbling or anything.:cool: Now I just have to bolt down that grinder. (What is the law that says that no matter how many bolts you have you will not have the ones you need. :doh: ) So, let me at the wood.:D I can now turn small to middling sized things at home. :wave:

NeilS
28th May 2009, 09:54 PM
I can now turn small to middling sized things at home.



:party5:.... there will be no stopping you now TL...:)


Neil

Ed Reiss
29th May 2009, 12:35 AM
GJ, after scanning your charts and numbers on threads, my head is ready to explode :club:...am now going for the duct tape and a cold one :2tsup::D