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Antique Steam Engine from Doorknob

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roy entwistle22/05/2019 09:15:52
1188 forum posts

If it's brass, and it looks like it, do NOT use WD40, WD40 is not a penetrating oil. Use something like Plus Gas


SillyOldDuffer22/05/2019 09:16:55
5913 forum posts
1280 photos
Posted by Hopper on 22/05/2019 08:22:46:
Posted by SillyOldDuffer on 20/05/2019 11:54:39:

Now there's no evidence of a coaxial crank I've gone off the idea in favour of this suggestion:


I'm not convinced on this exact set-up, but rather something similar but different, for several reasons. One being that the stroke of the cross-head is significantly longer than allowed by the small crank in red. In fact it would be the same dimension as the main crank, which obviously would clang into the main crankshaft. The other being that there is no facility for the "needle" to pivot at the top, as would be required in a crank and rod type situation. The notch in the brass flange where the needle would run tends also to indicate it does not move from side to side.

I'm thinking there must have been something that allowed the "needle" to move straight up and down. So something more like a pushrod pushing a lever, in effect a rocker arm, without the two being firmly joined. Or perhaps a short crank arm as shown in red but the pushrod passing though a loose hole in the end of it, with two collars on the pushrod that allow it to move the crank arm a short distance at the end of each stroke, but slide through without moving the crank until the other end of the stroke. You thus have a lost-motion linkage in effect. So it provides a sort of "switching" motion at TDC and BDC rather than a continous cranking motion. This would be consistent with switching the valves from open to closed and vice versa at the end of each stroke, as required for a single-acting cylinder.

Just a thought.

I like it!

It's true the crank suggestion isn't convincing. A reason I suggested ornamental was because I can't imagine how a crank would communicate sensibly with whatever valve is inside. (Might be because I don't know enough about valve gear and there is a simple solution!) And ornamental doesn't fit well with the maker going to the trouble of drilling that large hole - surely it has purpose.

Hopper's suggestion of a mostly up down movement using collars to flip the valve is much better than any of my over-complicated musings. Something like the valve trip arrangement on James Watt's early engines perhaps. I'd love to know what's inside!


Michael Gilligan22/05/2019 09:35:33
15864 forum posts
693 photos
Posted by roy entwistle on 22/05/2019 09:15:52:

... Use something like Plus Gas


+1 for that

Plus Gas Formula A, in a good old-fashioned can, is effective and economical.


Hopper22/05/2019 11:18:07
4645 forum posts
101 photos

Posted by SillyOldDuffer on 22/05/2019 09:16:55:...

...Something like the valve trip arrangement on James Watt's early engines perhaps. I'd love to know what's inside!


I'm thinking some kind of simple (yet cunning) rotary valve. Something like a piece of round bar inside a hole drilled in a solid block. The block has two small ports drilled right through it, each port connects to the cylinder above. Below, one port to the steam inlet pipe, the other to the exhaust. Two small holes drilled crossways through the round bar, at 90 degrees to each other, would allow through-flow through one port at a time. The round bar is rotated through 90 degrees by the "needle" and crank arm at the end of each stroke.

Or offset the ports slightly and file flats on the round bar to give finely tuneable valve timing and perhaps less than 90 degrees of rotation needed to make it work. My mental CAD abilities end about there. I need the back of a fag packet and a burnt match to take the concept any further.

Hopper22/05/2019 12:08:10
4645 forum posts
101 photos

Rotary valve shown here could be something like what's inside there *LINK*

Michael Hudson 622/05/2019 13:08:03
24 forum posts

A small update from me - have ordered some plus gas, have kept away from the wd40.. Very intrigued regarding the possible valve arrangement. I think I will try and talk to our vet and see if they will oblige with an X-Ray or two

Michael Hudson 615/01/2020 15:23:54
24 forum posts

And another update - it has been ages so apologies. we took it to Antiques Roadshow and as nice as the experience and expert were, didn't really learn anything. Not sure if it is going to make the TV but we'll see.

I asked our vet if we could try using the x-ray and he said bby all means but it won't help as their machines aren't powerful enough to get through brass. He suggested the repair shop televison program which I was a bit sceptical about at first but I've watched a few episodes now and they do seem to be very aware of the fragility of items and quite happy to leave well enough alone where required.

So I've got in touch with them and we'll see if they're interested in having a go. My application of plus gas didn't seem to help anything that wasn't turning turn. I'll keep you all posted!

Nicholas Farr03/05/2020 19:54:53
2312 forum posts
1136 photos

Hi, just seen this on Antiques Roadshow.

Regards Nick.

Nigel Graham 207/05/2020 00:09:16
667 forum posts
15 photos

Only just come across this.

What a lovely little machine!

If X-rays don't work for seeing what's inside, and you are understandably reluctant to open it up, if you know someone with access to one, an ultrasonic test-set might, just, help although such devices are really designed to find boundaries within solids, not solids inside cavities. Their transducers also need snug contact with the test area, which might be impossible on this engine with lots of small, curved surfaces.

In that engine's era, engine-builders had to be highly experimental with what was still quite new "technology"; trying all manner of variations on a theme, including different valves and valve-gears. Sometimes it was to circumvent patents, sometimes to be "new improved" - they were as keen on increasing efficiency then, as their professional descendants today. So when considering the "works" within the intriguing styling, it's possible this splendid little engine models some particular very latest idea of the time; or even embodies its own, original, very latest idea.

AdrianR07/05/2020 08:36:24
486 forum posts
25 photos

The Repair Shop on BBC could be a good place to take it.

pgk pgk07/05/2020 09:14:54
1842 forum posts
288 photos

X-ray technology at vet level depends on the system available. CR and DR digital systems will be limited to a single exposure so one becomes dependant on the absolute power of the x-ray generator and it's timers and punching through even thin brass is likely to be unsuccessful. A large animal vet with in-house facilities might have a way more powerful set than a companion vet guy. I did manage to play around with taking images through aluminium cans with the DR set-up I had but the generator was pretty darned powerful for a SA vet (to get down to short exposure times for cardiac pics). Good old fashioned film/developer systems might succeed by taking multiple exposures before developing but you can't just buy three/four sheets and a small amount of dev/fix assuming someone still kept their screened x-ray cassettes. It is possible to buy 'self-developing' x-ray film (it comes in a 2-part pouch) we used for the ocassional intra-oral dental pic but doesnt have intensifying screens so needs longer exposure times again. That type of film is available in a slightly bigger format than just the dental size most will be familiar with - about large enough for a spaniel's foot but I;d guess you'd be through half the pack playing with more and more repeat exposures trying to get lucky. As a newly qualified vet I once managed to x-ray a horses mandible in the field using a low powered newton-victor table top machine (the machine on the right in this image.. link )

But that took about 60 secs of exposure(s) and was just through dense bone. I took 3 pics at different exposure numbers and was lucky that when developed one came out ok.

If using ullrasound it fails to travel well through any air gaps (hence ultarsound gels). To get meaningful results here I'd guess you'd have to fill the item with an appropriate liquid and place in a liquid bath to have a sporting chance....


pgk pgk07/05/2020 09:15:58
1842 forum posts
288 photos

Link above too long

Had to send as second message.


Andrew Fiderkiewicz07/05/2020 09:30:25
3 forum posts

Didn't your little wonder star on the Antiques Road Show the other day? Surely there aren't two of them!

Nick Clarke 307/05/2020 09:31:38
809 forum posts
28 photos
Posted by pgk pgk on 07/05/2020 09:15:58:

Link above too long

Had to send as second message.


Your link doesn't work for me I'm afraid.(using Win10 & Edge)

It looks like your link is to the data of your image and not to a place on the internet where the image has been hosted and is available.

Edited By Nick Clarke 3 on 0

pgk pgk07/05/2020 10:14:47
1842 forum posts
288 photos

I'd guess that's a limitation of this site's link reference length. Try the link attempt below whch isa goodle search for newton victor and then displays a small pic to the right (on my system) of two macines.. again the table top model is the one on the right within that image. Or just search for newton-victor tabletop x-ray.


Martin 10007/05/2020 10:22:01
262 forum posts
6 photos

Antiques Roadshow Series 42

Around 30mins and 50 seconds in

Nicholas Farr07/05/2020 10:42:10
2312 forum posts
1136 photos
Posted by Nicholas Farr on 03/05/2020 19:54:53:

Hi, just seen this on Antiques Roadshow.

Regards Nick.

wink 2

Regards Nick.

Michael Hudson 607/05/2020 10:58:28
24 forum posts

Hi again everyone yep the antiques roadshow episode aired on Sunday, Marc was really nice and very enthusiastic but it was all over in a flash and we couldn’t go into any real technical exploration. I have applied for the repair shop (the vet I took it to suggested it actually!) and in the meantime have watched nearly every episode and they look like just the ticket, specifically Steve looks like the chap for it.
goodness knows what is going to happen with the filming but I’ll wait patiently for a while before trying anything else. I think Steve does take jobs on externally to the show which could be a half decent plan B.

Nick Clarke 307/05/2020 11:05:11
809 forum posts
28 photos

Steve Fletcher's business - **LINK**

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