Design of a Simple Model Steam engine.

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Anatol

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Hi Tony
thank you for being so generous with your accumulated wisdom.

I use PTFE plumbers tape which I make into string and it is used much the same as graphite yard is used.

I've been around, but graphite yard is so obscure it doesn't even come up in a google search!
So what is graphite yard and how do you used the PTFE tape as 'string'? Do you simply wrap it in a groove?

I usually use PTFE tape as any wear can be taken up by tightening the gland nut

if I understand correctly, this 'gland nut' is much like a maritime prop shaft stuffing box (I mess with boats).
Somewhere I saw someone using fuel or gas line compression fittings for this, replacing brass 'ring' with an o ring, which seemed clever

"I doubt I have the stamina for a book"

a book like yours could be collected chapters, articles and notes. Wrap an introduction and and an index around it and you've got a book. We're not writing War and Peace here :)
 

reubenT

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really good looking engine, steam power is fun no matter the size. Steam can be done crude and with little for tools, as an example of a young man from russia did. Doesn't look like a very safe boiler, but I heard he did do adequate job of pressure testing it to well over operating pressure. If I build an engine from scratch it will have to be for a full size truck with 4-5" cylinder bore and maybe 6-10" stroke in a two cy double acting version, with some sort of governor controlled variable cutoff valves.
 

Tony Bird

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Hi Anatol,

Thank you for being so generous with your accumulated wisdom.

I use PTFE plumbers tape which I make into string and it is used much the same as graphite yard is used.

I've been around, but graphite yard is so obscure it doesn't even come up in a google search!
So what is graphite yard and how do you used the PTFE tape as 'string'? Do you simply wrap it in a groove?

I usually use PTFE tape as any wear can be taken up by tightening the gland nut.

If I understand correctly, this 'gland nut' is much like a maritime prop shaft stuffing box (I mess with boats).
Somewhere I saw someone using fuel or gas line compression fittings for this, replacing brass 'ring' with an o ring, which seemed clever.

Sorry I should have written Graphited Yarn, its a cotton string with fine copper wire running through it and is impregnated with graphite. Here in the UK for modelling it comes in 3/5/6 mm sizes. The plumbers PTFE tape I get a length of and put one end in a vice the other in an electric drill and twist it I then fold it in half and do the same again producing a sort of string which is wound into a slot in a piston or around a piston/valve rod where it is compressed with a gland nut. Yes a stuffing box.

"I doubt I have the stamina for a book"

A book like yours could be collected chapters, articles and notes. Wrap an introduction and and an index around it and you've got a book. We're not writing War and Peace here. :)

Well if I get the time, maybe. At the moment I am trying to finish a garden railway which I started many years ago, so long ago in fact that some of the original work is starting to rot!

Regards Tony.
 
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