Jenny Wren - a tiny steam steam engine

[zx9]

...
and once again with a £1 coin for scale

View attachment 157321

got to say I'm pretty impressed with how well it works, and how it looks, the black firebox and wooden cladding just look so much better than plain brass.
...

And so you should be, I am amazed by what you have done. The problem solving drilling out the tiny pipes is way beyond my comprehension ( well it is not that is the wrong word, I just can not think of the right word to describe it).

 

[Kayos]

Wow

I would now have a pile of wonky and broken bits of brass

That’s seriously impressive

 

[Richard.]

Very impressed with all this optima. Very skilled intricate work. I’m especially impressed with just how long you’ve managed to hang on to that pound coin.
Mine don’t stay in my pocket any longer than 24 hours before they get ‘borrowed’ for the Morrison’s trolley.

 

[Parm]

Super impressive

 

[eLuSiVeMiTe]

Very impressed with all this optima. Very skilled intricate work. I’m especially impressed with just how long you’ve managed to hang on to that pound coin.
Mine don’t stay in my pocket any longer than 24 hours before they get ‘borrowed’ for the Morrison’s trolley.

buy her one of these.

https://www.poppyshop.org.uk/new-po...ZSLxkDv2B1Jyr7nGw2ih0cxcbS1bT8qoaAoxyEALw_wcB


This thread is worthy of a reread. Top Job @optima21 can we see a video of it running sometime.

 

[optima21]

And so you should be, I am amazed by what you have done. The problem solving drilling out the tiny pipes is way beyond my comprehension ( well it is not that is the wrong word, I just can not think of the right word to describe it).

its not that bad really, you get used to the size you're dealing with, the biggest part is thinking about how you want to do something.

Wow

I would now have a pile of wonky and broken bits of brass

That’s seriously impressive

ohh I did, like using 2ft of copper tube to get a 2" length drilled correctly. the advantage of something so small is that even if you get it wrong and have to scrap it, it only costs peanuts for materials. I have a habit of doing things wrongly so with something like this I get 2 or 3 times the amount of material I think I'll need.

Very impressed with all this optima. Very skilled intricate work. I’m especially impressed with just how long you’ve managed to hang on to that pound coin.
Mine don’t stay in my pocket any longer than 24 hours before they get ‘borrowed’ for the Morrison’s trolley.

shopping trolleys are the work of the devil, the last time I used one was to get an air compressor from lidl, I must have given that away 3 year ago now. ohh thats not a pound coin, its a flywheel blank I guess it has done alot of photo-bombing on this thread. ohh yeah and being from Yorkshire we tend to hold on to them.

This thread is worthy of a reread. Top Job @optima21 can we see a video of it running sometime.

when I get the other engine finished I'll try and do that, but think I'll have to get someone with a modern phone to do it for me. but until then, here is a philcraft version of the engine that you used to be able to buy. (I think mine looks better though)

 

[optima21]

time for another update, but no video yet

a couple or 3 weeks ago I visited my sister with my vertical steam engine to compare it to the one I bought for her about 25 years ago, which I think cost somewhere between £20 and £30, and they were mass produced in the far east. (I only made mine as you couldn't buy them anymore).

and it was looking a bit sorry for itself, but it did run first time after 25 years. the steam port was partially blocked and the port face on the cylinder and standard were refaced with a small slipstone. its still slightly leaky but works much better now. after a polish it looks like this

the vertical engine I made has had 3 or 4 hours running, but the brass tube that the crankshaft was running in (by the flywheel) had worn so I decided that it needed to be drilled out and a phoshor bronze bush fitted. after thinking about how to hold the engine accuartely to drill the hole for the bush, I decided the easiest was to mill a 3mm x 3mm notch out of a steel bar and then clamp the engine to that and then hold that in a milling machine vice

and then to turn a bush to be pushed into the hole. the bush was 1.7mm ID, 2.4mm OD and 4.5mm long.

and its back and running well again now.

Ive also finished the horizontal engine, so now there are 3 of them, and I still havn't made proper burners yet.

these engines have a habit of getting steamed when I make a cuppa for the following reasons

1) the kettle has been boiled so there is a source of boiling water
2) it takes between 1 an 3.5 minutes for them to create enough steam pressure to run (enough time to make a cuppa)
3) the run for about 15 minutes (enough time to drink a cuppa).

today I decided that I needed to do some "testing" on them, so connected them up with a 0 to 15psi pressure gauge and a digital rev counter to see what speed they are going at.

so here are the "performance" figures today for the engines all the engines were filled with 5cc of hot water and the burner had 3cc of methylated spirits in it.

the horizontal engine with wooden cladding.

Time to raise steam - 2 minutes
steam pressure to run engine 1psi
normal running pressure 1.6psi
normal running speed 2000 rpm
total run time (including time to raise steam) 17.5 minutes

the vertical engine with wooden cladding

Time to raise steam - 3 minutes
steam pressure to run engine 3psi
normal running pressure 6psi
normal running speed 2700 rpm
total run time (including time to raise steam) 18 minutes

the vertical engine without cladding

Time to raise steam - 3 minutes
steam pressure to run engine 2psi
normal running pressure 2.5psi
normal running speed 2250 rpm
total run time (including time to raise steam) 18 minutes

the above details are just to be taken as a bit of fun, but they do run at a lower pressure on steam than they do on compressed air. the steam loss on the port face makes a big difference as the amount of steam generated is so small, the vertical engines both have 4mm throw cranks (the horizontal engine is 5mm), so I would have expected the vertical engines to give similar performance. the vertical engine without wooden cladding has a lower working pressure than the wooden clad vertical engine, this may well be due to the steam leaking at the port face, it can be clearly seen, but there isnt really any on the other engine.

just need to get the burners done and a video taken of all three running together.

 

[RichardM]

Great job you've done. Would it be possible to fit brass hoops to hold the veneer in place?

 

[optima21]

Great job you've done. Would it be possible to fit brass hoops to hold the veneer in place?

yeah it would be possible, its just that the screw to hold the boiler banding in place wouldn't have looked as neat, as you get something like this (for mamod toys)

if the boiler was 2" diameter it would have been the way I went, as it would be have been a tiny detail, but as these boilers are so small they would have looked huge. you can buy 1/8" boiler banding off the roll so it would have been an easy option.

guess I'd better do another update, but no video yet.

I decided to make the meths burners look like the cladded section of the boilers, so they were turned from 1" diameter brass bar

with the tube just soft soldered in place and then clad like the boiler so look like this, the wick is 3mm and used for e-cigarettes, and being made from silica it doesn't burn, which means it lasts indefinately.

the base of the vertical engine needed to be modified by having a couple of flat bottomed holes machined into it so that when it is on a display base it doesnt move due to vibration when running. As it was glued in place with JB Weld it was easy enough to remove.

I decided that they needed a couple of proper bases to put them on, so after a while decided to go for a tiled look with a wooden border. so I got some 1/4" x 1/2" laminate tiles made for dolls houses off ebay

https://www.ebay.co.uk/itm/350914146881

but to get them to look right I needed to file the corners off them all so that they looked like they have been grouted. how much better do the ones on the left look?

these were then glued to some plywood to make a base from. I need to veneer a border onto the base, but didnt think I would be able to sand the sides accurately enough, so the bases were mounted on an angle plate and clocked up against the edge of the tiles.

and then sanded nice and flat

and Ive just started to use danish oil on some samples of veneer to show how they will look against the engines and tiles.

I think they'll look pretty good when they are finished, the bases will just set them off nicely

with a bit of luck I'll have them finished by Christmas.

 

[optima21]

and the final update of the build

after watching several videos on youtube about veneering, I decided to ignore them and do things my own way. much of this was due to the small size of the parts being veneered and adhesives recommended. I think it was ash veneer that I ended up using and used clear epoxy resin from the pound shop. its seems that pva wood glue is preferred, but that can cause the grain to raise due to the moisture content in it, and this may also have caused shrinkage, and my thinking was that with the epoxy it doesn't get absorbed by the veneer to the sam extent so will stay flat.
The sides of the base were done first had a thin coat of epoxy resin spread over it. and then a slightly oversize peice of veneer stuck onto it. this then had a steel bar placed on top of it to distribute the weight of a section of girder to hold it down. when this had set, it was then trimmed to size and the next side done.
The top edges had the mitres cut on them to finished size, with the outside edge being slightly oversize. the veneer then had the epoxy resin spread over it and was clamped in place with small clamps, using a small ruler to spread the claming load. one the epoxy resin had set the edges were trimmed.

both metods of clamping can be seen below

The finish applied was Danish Oil and 4 coats were used. this was applied with a cloth and then rubbed off the tiles after 20 minutes. A couple of stainless steel pins were then glued to the wooden bases with centres that matched the bases of the engines.

So there you go, theses are the finished engines, I'm really pleased with how they turned and look better than I could have hoped for. I've had some very pleasing comments from people who know about engineering and model making, especially when you see their work and hope that you'll be able to produce things to such a high standard.

If I knew it would have taken this long I wouldnt have started them, but I didnt and now I can say that I've finally finished a project. Ive been playing about with wickes, water and meths ratios and can now get both engines to run for 20 minutes. I'd say they are run in now, and from the amount of meths used, have each done about 25 to 30 hours running.

ohh and at last the a video of all 3 running, the first and last 9 seconds are at normal speed and the rest is in slow motion, nothing much happens during the video, it just shows them running.

and the horizontal engine has a party trick when it runs out of steam. In this case the burner has been removed to stop the engine. if you leave it for about 20 seconds, the boiler then has a vaccum in it (rather than being pressurised), so if you start to rotate the engine the wrong way, it will run for a few seconds in reverse as the air gets sucked into the boiler to reduce the vacuum.

 

[Parm]

Absolutely Stunning work with great attention to detail.

Wish I had that much patience

 

[MattH]

Great work, really impressed.

More impressive though was where on Earth you managed to find a milk bottle top.

 

[optima21]

More impressive though was where on Earth you managed to find a milk bottle top.

you mean in this pic

thats easy, Ive still got a milkman......

the milk bottles have special tops on at Christmas

 

[eLuSiVeMiTe]

Impressive as ever.
We still have a milkman in the village.

 

[arther dailey]

@optima21 ,thankyou for sending me the link to this thread , I had watched part way through then lost track for some reason, anyways brilliant work , can I say though for others some years down the road I think you should have a little plaque with your name etc on them include a few details as in years to come some one will be looking at these as antiques and will wonder in amazement who and how they were made. just a thought . and really you still have a milkman ! we did till a few years back when the half crate we got delivered was half inched of by the gates ..so cancelled it. cheers and look forward to your next thread

 

[Misterg]

Thanks for bumping this - Fantastic work!