Edison dynamo

[goldstar31]

Incidentally and back to dynamos, what happened to Joseph Swan in all this, please?

Again, no mention of the first electric light in the home by Armstrong. It was water powered and the water came into Cragside from- Nelly's Moss Lakes

The name Swan also appears in shipbuilding especially on the Tyne. Grand son or great grandson or whatever was involved in shipbuilding until the firm went bust. David and his kids were neighbours of mine.

 

[Pedro Walter Lamberti]

Yes quite so he reduced Maxwell's correct but rather long winded ideas to something more manageable among his other many accomplishments including research into Characteristic Impedance leading to the development (and patenting) of the coaxial cable.

I think Europeans and the British in particular have a tendancy towards science as an end in itself whereas Americans are more open to the commercial and practical applications of ideas, which may explain why many European scientists tend to be less well known.

Best Regards Mark

It is not completely true. William Thomson (Lord Kelvin) was an extraordinary physicist, with great contributions to basic science (electromagnetism and thermodynamics). However, it was related to many technical and commercial ventures. He was in charge of designing the laying of the transoceanic telegraph cable. In addition, in some European museums there are still navigation devices with the Kelvin brand.

Best Regards, Pedro

 

[awake]

The typical 7x12 mini-lathes (and variants) typically use 16 tpi leadscrews - at least for the ones sold in the USA. I would guess units sold in other countries might have metric leadscrews?

 

[goldstar31]

The typical 7x12 mini-lathes (and variants) typically use 16 tpi leadscrews - at least for the ones sold in the USA. I would guess units sold in other countries might have metric leadscrews?

I have no idea about the UK 7 x 12 varieties but the larger C4 from Sieg is metric to go with the metrication here.
To go in an out between both only requires a transposing gear. 127 is the exact translation but will not fit the Myford in 20DP form. Hence 63 is normal but with a decent banjo( don't be daft) it is possible to get reasonable results with 20's

But £350 I got metric outfit and for a few quid more, I could convert the bulk of my Myford accessories to work on the Metric Sieg and vice versa.

I'm NOT an engineer but I did Economics and Accountancy way back in the days of blackboards and chalk.

 

[Richard Hed]

I guess I should have been more specific.
If you are threading inch threads on a metric lathe you can't usually disengage the halfnuts and pick up the threads with a thread dial or vise versa. You can do it but not easily, there is a good explanation of why in the Martin Cleeve book Screwcutting in the Lathe, pp 73, 79. One of the examples he uses suggests that if you wanted to cut a 1.75 mm pitch screw on a lathe with an 8 tpi leadscrew with a 50/127 translation ratio, if you disengage the halfnuts, you'd have to wait until the leadscrew turned 874 times before you could re-engage the halfnuts. He also says that geared thread dials for metric threads on inch machines is possible as well but not particularly useful and I've never seen a setup like that in 45+ years.
Is it possible, yes, practical, no in most cases.

What you are saying makes me thimk of exactly what method I used: I markt an even thread marker on the dial and waited for that to come around to that mark only to engage the half nut. -- Still no goo. So I built a hand turning device that one of the Brits had on utube and simply left the nut in place, cutting threads on the in and backing out all by hand. I thot I was going to destroy my carbide blade, but only chipt it once. Since my son helpt me do this, I had to make sure HE knew not to stop once a thread was started. Of course it was much easier with two peeps anyway, as I didn't have to look while turning. So far I have done two of these for an ER set of collets. Want to do ER-11, 25, and 40. and possibly design something that would work for even larger pieces.

Anybody got any ideas on that? I was thimking maybe using ER-40 body with some kind of enlarged chuck that sticks out of the body made to grip something maybe up to twice as large as "40". Somebody probably already makes something like this.