Antique Steam Engine Diagnostic Kit

A bit of self promotion?

Yeah, but why not? Pretty on topic for this group, and the quality of his photos sure made it worth a look.

Anyone else notice the slotted attachment holes on the two scales of that steam thermometer? Must have been how they tweaked the calibration, at least at one temperature point.

I assume the glass stem on that style of thermometer has to make a right angle turn at the bottom. Never thought about that one before...

I wonder if the threaded cap on that thermometer adaptor kept oil or another liquid (used for thermal conductivity I guess?) from spilling out when it wasn't attached to the thermometer.

Jeff

That is a nice indicator set, typically you only see 1, not 3. I wonder why

3? I could understand 2 for making both front and back cards at once, but 3 hmmm.. Typicaly they would just have 2 sets of valves on the front and back sides of the piston and make the front and back card on the same drum (usually even on the same card) by closing one valve and opening the other. The trouble with that is the diagrams are mirror images.. With 2 drums you could run one 'backwards' and get the diagrams going 'the same way'... easyer to compare...

Dave

The item in the case with the purple velvet lining is an integrator, which sums the area under a curve by tracing the outline of it while the little wheel slides on the paper.

I believe that it *does* belong with the set, as the set's function is to draw a "card" relating pressure in the cylinders to piston travel, and by integrating that card, you can calculate the power developed by the piston. (Taking into account the active area of the piston (e.g. minus the con rod area), and the piston stroke, as well as the full scale value determined by which spring set you screwed in.

I don't have a need for the set -- but it still is somewhat tempting. However -- I'll leave it to someone who will *use* it, and not muddy the waters in the auction.

Good Luck, DoN.

P.S. As for spelling gauge/gage -- both are common, and anyone who might think to look for this on eBay should check under both spellings.

"DoN. Nichols" wrote: (clip) The item in the case with the purple velvet lining is an integrator, which sums the area under a curve by tracing the outline of it while the little wheel slides on the paper. (clip) ^^^^^^^^^^^^^^^ I was not able to find the picture you are referring to, but you are essentially correct. The area inside the loop on the card, multiplied by the right scale factors, represents the energy in a power stroke. If you divide this area by the length of the stroke, you get the "mean effective pressure." The only correction I will offer is that the thing you call an "integrator" is usually called a "planimeter."

Its for a triple expansion engine, one card writer per cylinder. The pen is pushed up the cylinder by pressure in the cylinder and the card is rotated by a string that connects to the cross head. The result is a plot of pressure vs. displacement . Integration by the planimeter gives horsepower after a few calculations.

His comment concerned the incorrect spelling of "gauge" as "guage". The spelling variation "gage" wasn't mentioned ... which is curious as I would have thought that the latter was the more common American spelling (as opposed to the British/Canadian/Australian "gauge" ).

It raises a point though. Whenever I'm searching ebay for something I'm seriously interested in, I try to imaging all the common mis-spellings that might fit and include them in the search. I've quite frequently turned up additional listings that way.

Tom, Never thought about doing a tripple expansion engine, interesting idea. I'm quite aware how they work. I've actually done this 'modern day' with a 'scope and presure transducer'... One of my ongoing projects is building a rig out of a single chip micro and 4 transducers to send the info in a serial stream to a laptop on a riding car. Dave

I was trying to remember the name. I've even got one, but it was too late for me to dig mine up. But integrator is still the function.

Thanks, DoN.