Steam Engine Number One

[Iain DownsParticipant @iaindowns78295]

Thanks, Jason.

I have honed the cylinder, but have I honed it enough? I will take out the rings for now – this seems the most expedient.

Iain

[Paul KempParticipant @paulkemp46892]

Ian,

First off, congratulations on having got this far, this is a great thread, really enjoyed reading.

Did you gap your rings? By that I mean set into the bore (off the piston) and measure the gap between the ends of the ring? At a very rough estimate you should be looking for 0.006” to 0.010” gap.

it is not unusual for new rings in a new bore to be a bit stiff, as an example on the full size Avelling tractor I put together it was all I could do to pull the piston through the bore but after a few minutes running when we finally steamed it, it freed up in the first run. Similarly my half size traction engine cylinder is tight but it moves easily on 10 psi air pressure. It has not been erected onto the engine yet only blown back and forth by manually moving the slide valve spindle but even in the few movements it has done on the bench it has got a lot freer than when first assembled.

So in short, if you know you have a gap in the rings and can get plenty of oil in, I wouldn’t worry too much. Just a point on the oil, I wouldn’t use 3in1 if you can’t lay your hands on some 460 bearing oil or 680 steam oil at the very least use motor oil. I can’t remember if you have made provision for a lubricator? A displacement lubricator on the steam inlet to the valve chest would be a good accessory

Paul.

[Iain DownsParticipant @iaindowns78295]

Thanks Paul!

There is a gap of somewhere around .010", so I think I'm more or less on track. Ah – just re-read your post. No there will be no gap in the cylinder (or not much. They were sized to be a close fit. There is a gap around what you said when out of the bore. I did think of taking a little off the gap as a first step, so that's encouraging.

Is 460 bearing oil way Oil? I have that and some gear oil. I will be running this on air for the moment (discussions of boilers will come later!) and have an air oiler.

I've followed Jason's suggestion and removed the rings for now (breaking one and twisting the other – may need a re-do).

Somewhere in the next two or three hours I will be popping out to the shed and applying some compressed air. I have NO IDEA what will happen. If anything moves at all, I will call it a success and retire with a glass of something.

I will leave this post with the machine assembled and ready to play.

You will see that there are still a few bits which are not perfect (most obviously the eccentric rod bearing), but I'm pretty pleased with how it has turned out.

So if you find this is my last post in this thread because the damnable thing won't run, I will pretend it was intended as a work of art all along and not a working machine. Surely the Tate modern will pay a fortune for a complex piece of machinery which doesn't quite work – a metaphor for modern society, perhaps?

Iain.

[JasonBModerator @jasonb]

Fingers Crossed for you.

Yes you need a small gap when the split ring is placed into the cylinder, a few strokes with a needle file is usually enough and just tidies up the split ends where the ring was snapped. Use the piston to push the ring slightly into the bore so it is not tilted which will give false gap.

For air running I use quite alight oil. Clock oil works well on the very small engines or 32wt oil that I use on the lathe for larger engines, A couple of drops into the inlet before the air is turned on will carry it through into the valve and cylinder. With luck some black oil will be forthcoming from the exhaust as the engine beds in. Steam oil can be a bit sticky at room temperature but OK once warmed up by steam.

[Iain DownsParticipant @iaindowns78295]

Sorry about the long delay – no doubt you were all gagging to find out if it worked or not – though equally you might have guessed that things weren't perfect due to the lack of crowing…

In fact I've spent most of the time since Christmas re-organising my shed with various levels of success. Today, though, I had no more excuses and cracked on with trying to get it set up. NO more waiting ..

 

As you might guess my first go just didn't work and it was too late to mess about. With this one, I played with the timing and filled the glands with carbon wire stuff. I've only tried it in one direction and not tried to tune it past 'it works' (quit whilst you're ahead!). Still not put the piston rings in.

 

I am, of course delighted.

 

 

Iain

Edited By Iain Downs on 06/02/2022 17:25:07

[JasonBModerator @jasonb]

Well done Iain, looks to be running well

[Paul KempParticipant @paulkemp46892]

Well done, that doesn’t look too bad at all, considering you designed it yourself and it was a first attempt I think you should be very pleased.

Paul

[Andy_GParticipant @andy_g]

Posted by Iain Downs on 06/02/2022 17:24:36:

Sorry about the long delay – no doubt you were all gagging to find out if it worked or not…

Absolutely!

Congratulations and very well done!

[Author]

Posts