Norton Atlas tach drive
- Thread starter drp
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- May 28, 2003
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- 2,591
+1
1/2" measured .493" & 26tpi with pitch gauge
http://www.tracytools.com/taps-and-dies/cycle- taps-dies?product_id=975
whitworth ?
then try here:
http://www.tracytools.com/taps-and-dies/whitform-taps-dies?product_id=1098
Tried my 1/2-26 die (sold as CEI) and it barely scratched a hair off the tach gbox.
1/2" measured .493" & 26tpi with pitch gauge
http://www.tracytools.com/taps-and-dies/cycle- taps-dies?product_id=975
whitworth ?
then try here:
http://www.tracytools.com/taps-and-dies/whitform-taps-dies?product_id=1098
Tried my 1/2-26 die (sold as CEI) and it barely scratched a hair off the tach gbox.
+1 also.
With the important note that there is nothing 'Whitworth' about it,
it is 26 tpi Cycle Thread.
Americans generally just don't seem to understand British thread systems,
and how there are a number of such systems that share ONLY the hex/nut sizes....
With the important note that there is nothing 'Whitworth' about it,
it is 26 tpi Cycle Thread.
Americans generally just don't seem to understand British thread systems,
and how there are a number of such systems that share ONLY the hex/nut sizes....
This is a voyage of discovery !
Where findeth ye that diagram. !?
And, who drew it - and is it likely to be accurately labelled ?
Now, everyone knows that that 1/2" Whitworth is 12 tpi, so what is one with 26 tpi called ?
Now2, my tacho drive is brass, so is it 26 tpi brass thread ??
Which could only be, very loosely. referred to as a 'whitworth' thread.
(whitworth must be one of the most loosely used technical terms in the english language.)
L.A.B. said:
Where findeth ye that diagram. !?
And, who drew it - and is it likely to be accurately labelled ?
Now, everyone knows that that 1/2" Whitworth is 12 tpi, so what is one with 26 tpi called ?
Now2, my tacho drive is brass, so is it 26 tpi brass thread ??
Which could only be, very loosely. referred to as a 'whitworth' thread.
(whitworth must be one of the most loosely used technical terms in the english language.)
- Joined
- Nov 20, 2004
- Messages
- 20,371
Rohan said:
In a Smiths catalogue.
Rohan said:
I don't know. Probably not Mr Smith.
Rohan said:
As it's in a Smiths publication then I'd think there's a reasonably high chance it's accurate.
Rohan said:
'Brass' thread has a 'Whitworth' threadform. Note the term "WHIT. FORM" on the drawing. If it has a Whitworth threadform then it can't be 'Cycle' thread.
https://en.wikipedia.org/wiki/British_Standard_Brass
http://www.britishfasteners.com/threads/bsb.html
If it has 26 tpi, then its not part of the recognised Whitworth thread system !!
Now, I have a part set of Brass Thread taps and dies, 26 tpi.
55 degrees, not the 60 degrees of Cycle Thread.
Model steam engines, etc.
Although 1/2" is a bit bigger than usual.
Although maybe not for tacho drives.
I notice the speedo drive uses a different size thread.
What would that be. ?
BTW, I notice too than an Atlas tacho cable uses about exactly the same cable as a
prewar Norton speedo drive (off the front wheel). Same fittings, same length ?
PPS. Perhaps we should ask if UNF and UNC have the same 'thread form' ?
Now, I have a part set of Brass Thread taps and dies, 26 tpi.
55 degrees, not the 60 degrees of Cycle Thread.
Model steam engines, etc.
Although 1/2" is a bit bigger than usual.
Although maybe not for tacho drives.
I notice the speedo drive uses a different size thread.
What would that be. ?
BTW, I notice too than an Atlas tacho cable uses about exactly the same cable as a
prewar Norton speedo drive (off the front wheel). Same fittings, same length ?
PPS. Perhaps we should ask if UNF and UNC have the same 'thread form' ?
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- Nov 20, 2004
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- 20,371
Rohan said:
As already stated, it's Whitworth thread form.
Rohan said:
Depends which "different size" you mean?
Rohan said:
And why would "we" need to ask that?
http://www.britishfasteners.com/threads/unf.html
UNF
http://www.britishfasteners.com/threads/unc.html
UNC
- Joined
- Mar 23, 2012
- Messages
- 206
I've found this.
There seems to be a difference between 1/2" BRASS and 1/2" CEI
Fritz
There seems to be a difference between 1/2" BRASS and 1/2" CEI
Fritz
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- Jun 30, 2012
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- 13,901
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