lathe to cut 26tpi

[JasonBModerator @jasonb]

Just come up from the workshop so will check tomorrow. I do have two 80T gears which are used for fine feed.

[ChrisBParticipant @chrisb35596]

With my imperial 280 I got both a 65T gear and two 80T gears

[Robert Graham 2Participant @robertgraham2]

as my new wm 280 imperial lathe arrived today I can confirm a 65t gear and 2 80t gears

[Ian HewsonParticipant @ianhewson99641]

My myford 254s has 26 tpi as standard in the gearbox.

[John Duncker 1Participant @johnduncker1]

I am only piling in on this thread because I have been gobsmacked to find that my 7 x 12 mini lathe as supplied to the US market comes with an imperial leadscrew and will cut both 20 and 26 tpi.

But I am sure everyone here new that so I will shut up about my new toy.

Why was I gobsmacked well it turns out that the leadscrew is imperial but the cross slide and compound are metric.

[Jeff DaymanParticipant @jeffdayman43397]

South Bend 9" lathes (like my 1949 model) can cut 26 TPI just FYI.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by John Duncker 1 on 20/02/2019 21:40:48:

Why was I gobsmacked well it turns out that the leadscrew is imperial but the cross slide and compound are metric

You are in good company – all metric series 7 Myford lathes had 8 tpi leadscrews.

Rod

[not done it yetParticipant @notdoneityet]

3.2mm is close enough to 3mm for a myford? Not that even a 3mm pitch would be so useful!

[Nick Clarke 3Participant @nickclarke3]

The Leica Screw Mount used on Leica cameras for 40 odd years or so was 39mm x 26tpi – an interesting mix of standards.

Soviet copies were supposed to be all metric, 39mm x 1mm, but I am not certain about Japanese Canon screw mount cameras, however all three readily interchange (at least as far as the screw thread is concerned) and mount accurately and securely.

[Nick Clarke 3Participant @nickclarke3]

Posted by Neil Wyatt on 16/01/2019 12:58:08:

'Country of manufacture' has a legal definition as the country where the last substantive manufacturing process was carried out (attaching a sticker probably would not count, assembling individual parts probably would).

In that case my Chinese mini lathe which came with the crossslide and tailstock handles separate so I had to screw them into the knobs qualifies as British then?

[Chris TriceParticipant @christrice43267]

Posted by not done it yet on 20/02/2019 23:03:33:

3.2mm is close enough to 3mm for a myford? Not that even a 3mm pitch would be so useful!

3.175mm please.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Nick Clarke 3 on 22/02/2019 08:54:40:

Posted by Neil Wyatt on 16/01/2019 12:58:08:

'Country of manufacture' has a legal definition as the country where the last substantive manufacturing process was carried out (attaching a sticker probably would not count, assembling individual parts probably would).

In that case my Chinese mini lathe which came with the crossslide and tailstock handles separate so I had to screw them into the knobs qualifies as British then?

Maybe. Though more likely in your example to have been done to reduce the risk of damage in transit, unfinished goods are often supplied that way to avoid tax and tariffs.

Kits (requiring assembly to produce a working item) are often taxed at a reduced rate compared with finished goods. I've bought kits recently from the USA and Bulgaria, where all I needed to do was put them into the case provided, which is stretching the definition of a kit. Saved me a lot of money though. Similar arrangements are often agreed for much larger items like aircraft and car making. Sometimes the country of manufacture makes nothing of a car itself – all the parts are imported, like as not from many other countries.

Modern supply-chains are usually multi-national and finely tuned to avoid costs, not only tax, during manufacture, finance, warehousing, transport, export, import, administration and retail. International supply-chains often depend on hard to negotiate Trade Deals – make your own mind up about the risks to supply, prices and jobs if a trading nation goes global without agreements in place…

Dave

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