Member postings for Francois Meunier

the original patent by Eugène Bourdon for its" tube" and application can be found on the INPI site, base brevets du 19ème siècle.

this a manuscript, hardly readable : 33p of finely hand written text with a few figures, looking really odd.

you can read only, no downloading, but you can order a copy. pretty deceptive!

hope lhe link works ,

http://bases-brevets19e.inpi.fr/Thot/FrmLotDocFrame.asp

oscillators are usually proposed to the beginner, but I guess it is a poor way to learn engineering, oscillator even poorly fitted will run, simply increase pressure, fun to to watch but useless as regards learning machining skill. As suggested above, refurbishing an engine, making new piston to close tolerance and getting good compression is IMO far more instructive and not that difficult for a teenager already RC flight fan.
Zephyrin

Hi

for a large engine too, I was tempted to build a boiler similar to this one, riveted and soft soldered only, it looks nice and strong, or should I stop to chicken out and go for a brased job ?

**LINK**

Cheers

Zephyrin

You will find the responses in the late Charlie Dockstader Valve gears simulator programs (still available on the net), you enter your data, yes, the complete valve gear set up of your own loco from the main driver to the valve and piston, and run the program and you will see your loco running before being finished ! there are no approximations or "equivalent eccentric" in it, only exact geometric valve positions during run.

you would be able to change dynamically the data (ie link length, pivot postions or angular setting etc) see their effects on valve events and the diagrams, then tune your dimensions to get the steam distribution you wish as regards advance, cut-off, symetry...

**LINK**

upon heating to red and quenching in oil, your worn piston do hardly enter in the cylinder, amazing, it gives some meat to lap again, the increase in dia was about 0.02 mm for a 25 mm piston, but not not regular, more pronunced on the lower, thinner part, somewhat oval too..., may be not quenched properly.

Zephyrin

Edited By gedeon spilett on 16/04/2013 21:28:25

For a steam boiler, copper and brass will undergo a rapid hardening upon pressure test and later use. Old bits of brased brass parts reharden spontanously in my scrap bin (much less "drill bit snatching" after "a while" , I can't be more precise. Old brass music instruments also, up to the point of crevices on the thinnest parts.

Zephyrin

nice gauge you have, with vacuum too, more akin to a scientific instrument than a boiler gauge. I have one, a boiler gauge, and I use it regularly, a faithful Instrument...not only a mantlepiece curiosity.

Cheers

**LINK**

I can cope with imperfect drawings.
numerous model engineer build great engines that work very well, without any drawings, at most a few sketches on the back of an envelope, and some do blue prints afterwards, which is not the proper way to proceed in industry, but they allow others mates to copy their model, I should therefore like to thank them.
Moreover, these drawings are not set in stone, and are generally adapted to take account of tools and materials available in our workshops (ie Imperials or metric taps and dies ..).

Cheers

Zephyrin

ETW, redesigned and republished 20 years later (24 NOVEMBER 1960 issue, p. 635) his Kiwi engine, with weaker valve springs !
quote
"I am often severely rapped by readers for neglecting to give details of valve springs, but it is difficult to specify essential dimensions, because ultimate strength and durability depend on several factors, including not only the quality and temper of the spring steel, but also the pre-stressing of the material in manufacture. For the best results, some experiment is called for; the springs which have been found satrsfactory are 3/4 in. free length, 5/16 in. outside diameter, by 20 s.w.g., with six complete turns, not including the flattened end turns." ME, 123, p. 635, (issue 3098, 24 Nov. 1960).

I recently did a 10 cc engine (video in my album) and was surprised by the raise in performance with the progressive increase in stiffness of the springs, about 2,2 kg to open the valve now.
Cheers

https://picasaweb.google.com/113249908069844921550

Edited By gedeon spilett on 17/01/2013 08:22:48

Hi

It reminds me of a roll top desk that I recycled into a workshop: once opened, a unimat SL and many hand tools, and after removing the vertical column and the vise and closed (and locked!) the cover, impossible to guess what I was making inside.

I have spent so many pleasant hours with it; I have made many oscillating engines and even a Stuart D10. Not louder than the vacuum cleaner necessary after a turning session to clean the rain of brass swarfs. The motor does not turn the whole day anyway, many machining and fitting sessions are silent and do not prevent listening to music or the radio. Must also avoid spraying and flooding with oil and coolant, a small brush is sufficient.

Clearly, I am a lot more comfortable in my garage now, and I make much larger models, but I have spent with my desktop workshop some of the happiest moment of my life, I was also much much younger...

I still have the Unimat, I will try to find a place for it inside, like in my youth, my garage is getting pretty chilly these days…

cheers

I am very happy to show my engines and my models to other model engineers and other experts even if it is to be criticized, but I do not like to show what I do to people who know me and who know nothing in model engineering and generally laugh at it (poor morons).

so there is nom de plume

In his book "projects for the Unimat", Rex Tingey published drawings an building notes for a 1/16 scale traction engine "Sweet Sixteen", at large a reduced version of Minnie but the engine of his own valveless design. I did it many years ago, replacing the ugly cylinder by a plain reduced version of the minnie cylinder and valve gears, a awkward and minute job I remember..but very happy with the result. you can see a picture in my picasa album

Cheers

**LINK**

Hi

nice engine, surely fascinating to watch running

You can find here an interesting discussion by J Ericsson himself on its Ironclad Monitor and also on the efficiency of its engine and some reasoning on its design. beautiful and dramatic engraving of the vessel and a few plate of the engine too. pages 479 & seq. & plates 48- 52).
it is a huge document but really worth a look.
Contributions to the Centennial Exhibition (1876) by John Ericsson
http://archive.org/details/contributionstoc00eric

Zephyrin

Hi Saxalby

Smart & elegant tool you made.

How do you change the protruding length of the screw/bolt ? is the pad on which the head of the screw rests movable ? applying side thrust for forming the end of a long and slender screw is not possible. I did a similar tool of the John Wilding design (in "Using the small lathe" and I have to make a brass sleeve for each length for not getting bent screw, impossible to remove from the tool.

Zephyrin

however, I have no address for castings, it’s a pity
we don’t have here a dedidated trade for model engineers.
I also order At CES without problems, but for heavy items.
(I ordered last week small loco wheels at Walsall Model Industries in UK,
no faster deliveries and no better quality, amazing)
Cheers

Zephyrin