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Is it a peak pressure indicator recorder, to capture the peak for individual cylinders of main engine. What looks like hose fitting at the bottom attaches to indicator cock and string to fuel rack for cylinder being tested? Produces a graphic record, is this for state of cylinder/fuel calorific value, both or none of the above.

 

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The string no doubt suspends a weight, that drives the drum that holds the graph paper that the lever arm writes on that records the pressure.

And the two-lugged screw-fitting attaches to a T on a pressure line.

But are we missing something that is more unique?   So far I feel like I'm being asked to ID a car from a picture of it's tyre!

But just the thing for lockdown time!

John

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1 hour ago, John I said:

Is it a peak pressure indicator recorder, to capture the peak for individual cylinders of main engine. What looks like hose fitting at the bottom attaches to indicator cock and string to fuel rack for cylinder being tested? Produces a graphic record, is this for state of cylinder/fuel calorific value, both or none of the above.

 

99% right.

It screws onto the indicator cock on each cylinder and measures the pressure throughout the stroke (not just the peak). The arm attached the right section with the spring moves up and down with the pressure, and has a pencil or similar attached.

The cord attaches to an indicator drive which turns the barrel back and forth.

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You should (being very much the operative word) end up with a diagram similar to the above banana shaped diagram. If you then manage to calculate the area inside the banana you can apply a formula to determine the power output of that cylinder. By taking all cylinders you can determine the power balance, and adjust to make each cylinder equal.

Set the machine at 90° (don't ask me how, this is a dark art) and you get the mountain peak diagram. This shows the characteristics of Compression pressure, injection pressure and timing, and maximum (combustion) pressure. These allow us to ensure the engine is running as per original specification, and also diagnose any issues that can (and do) occur.

As said above, this is really a dark art. The old guys had plenty of practice taking these measurements, but even then some parts were still a matter of "interpretation". Fortunately in these modern days this is all measured by sensors and a computer, and the results are slightly more reliable.

Phil

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Well done John I !  New one on me, but what a useful gadget.

51 minutes ago, thebrookster said:

Fortunately in these modern days this is all measured by sensors and a computer, and the results are slightly more reliable.

I have no trouble believing this though!

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  • 1 month later...

Hello, Here is another mystery. Belonged to an old mate who has passed on. He was very mechanical/engineering, his last job before he retired was supervising building the mechanism that the '"Dish"of the Telescope at Parkes revovles on. Regards,Michael. I don't know either. 

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Two ?threaded holes on one side, two unthreaded on the other.   A slot all the way around.

Is this a security lock for some container?    The slot would have a circlip in it, running in a corresponding slot in the ?door.

The threaded holes would bear a lever that would lock the door closed, while the unthreaded would engage in a key.

But then, why is it hexagonal?    A spanner would tunr it, no need for a key.  Back to the imagining board!

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  • 2 months later...

Even people whose life's work is to document science and technology come across objects that make them say, What on Earth is this?

The Science Museum in London is such a place, and they have more such objects that anywhere else.      They have been moving their  collection, that isn't on exhibition from London to a new storage warehouse, in Wiltshire.   300,000 of them!   Many of which have not been looked at since someone gave them to, or they were bought for, the Museum.  The Museum would like members of the public to tell them what these objects are and what they did.   

An article in the Guardian shows a few objects: https://www.theguardian.com/science/gallery/2020/jul/19/mystery-objects-from-the-science-museum-in-pictures

And one from the Museum itself, shows some more: https://blog.scienceandindustrymuseum.org.uk/museum-mystery-objects/

Perhaps the assembled academics in the Sideways U. Common Room can tell them?

My guess is about the copper alloy tool, Tool with wedge-shaped head

I'm going to suggest that it's a welding 'spoon', used to backup thin metal, so that it doesn't 'blow-through'.

John

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Fantastic, Sam, nice find!   Nice archeology, too, plus the good Professor's caution on interpretation without confirmation!

Total thread diversion, but I waiting for the TV series that deals with all those ancient re-enactors.     You know, the ones who dress up as Roman soldiers (or Civil War (US or UK) or even WW2) and march about the country in sandals.        We see them sometimes in historical drama, at events battling it out, or as a side issue in archeology progs, but no one has done a series on them.     I mean, do they knit their chain mail?   And are sandals good to march on?

Right back to What is it?

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17 minutes ago, JohnD said:

 I mean, do they knit their chain mail?

I've made chain mail a number of different ways, the authentic middle ages way is so labour intensive it's unreal.

The myth about not being able to move in armour is total nonsense, I have a full set of full-contact rated plate armour and when I was in my 20s I could RUN in it!

 

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  • 7 months later...

Nick, are you thinking of a cheese trier?

 

rare vintage cheese core sampler with sheath | #1881259882

But there the scoop goes all the way up.

 

A "Spoon bit", SBGT?    Never heard of that, but always glad to learn, so thank you!

And sure enough, here's a video on forging and using one!     It's traditionally a chairmakers tool the author says, will bore a hole in a round leg, for the strechers, for instance, that is almost all the way through, but doesn't break the surface.

Michael, did yours originally have a tommy bar to drive it by hand, throught that loop on the end?

Edited by JohnD
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  • 6 months later...

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