An oscillating overhead-crankshaft engine for a paddlewheeler.

[kno3]

Hi!
I have recently acquired an oscillating steam engine and boiler. It is made after plans by Basil Harley, for the Miranda steam launch. That's what it looked like when I got it, ready to be put to good use in a propeller driven launch:



But I had other plans with it 
It just happens that this engine can easily be turned into a overhead crankshaft oscillator, which would be perfect for a paddle-wheeler. So I started disassembling and rearranging parts:


Here's the result of just changing the position of the parts, no modification whatsoever involved:




In my opinion it now looks realistic and quite  close to the real-life oscillating engines that power paddle-wheel ships from the 1870'ies and 1880'ies, found even today on European rivers (Elbe, Danube etc.).

[steamboatmodel]

That is fantastic. Thank you for figuring it out.
You now have us all hitting our heads saying "now why didn't I think of that!"
Basil Harley would have been very impressed. Now where did I put those magazines with the Miranda build in them.
Regards,
Gerald.

[Hankwilliams]

Very well in construction an even optical! Looks exactly like the engines of the older Elbe paddlers.

Congratulations!

Thomas

[kno3]

Thanks!
I think I'm going to paint the cylinders black and keep the rest shiny brass and the upper and lower frames dark green, to be closer to the originals.

[Misterbee]

Well done kno3. You have stumbled on the Aussie version, which is upside down for the southern hemisphere of course.

Cheers.
Misterbee.

[kno3]

You mean you've been doing this all along? 

[kno3]

Hi all,

here the next step in converting this oscillator in a paddle-wheeler engine. I've disassembled it completely for refurbishment, doing the following (sorry, forgot to take pictures of all stages):
1. Cleaning old paint from cylinders, then blackening them chemically.







2. Changing old worn piston rings with Teflon.
(no pictures)

3. Painting the crankshaft bearings and base.





4. Cutting 7 BA hex head screws to size, to replace all slotted head screws previously used for the cylinders and crankshaft. I had to keep the fine slotted screws for the piston rod connection to the crankshaft, as the were countersunk, so no way of putting hex head there. Adding some feet (4 BA screws) to clear the bottom of the cylinders.

[kno3]

Here's a short video of the engine run on air:
http://www.youtube.com/watch?v=TqUhyPwO-9Y

[derekwarner_decoy]

well PD's........may only be 5 seconds......but well done kno3  ....Derek

[gyula]

Nice work...
Hope we shall see it soon in something like this:
http://www.youtube.com/watch?v=cvu-FmEXy2I

[kno3]

That was my inspiration!

[abcdale]

nice job ... I have this engine in my miranda ,(but not upside down) you mention teflon rings??? mine appeatr to have  cotton in my rings    would that be  correct? ... you can probably guess , I can,t get mine to work at the moment .... and I have million questions

[derekwarner_decoy]

Hi PD's....welcome abcdale........is the suspect piston ring hemp/cotton twine  grey in colour?...if so it could be a braided graphite impregnated material.......just like the old James Walker steam gland packing material......

This type of packing is fine for steam use, however in static applications [gland] but not designed for dynamic [piston] applications  ....having said this....it will work on low pressure & low temperature steam engines as the steam oil lubrication stops the hemp/cotton material from drying out ....Derek

[kno3]

abcdale: Originally there was some sort of cotton/hemp or so in the piston groove, which I have discarded and replaced with Teflon tape.
It's really easy to do, just twist the Teflon tape until you get a string and wind a suitable length tightly in the piston groove, then roll it on a wooden surface to press it in a bit, so it fits the cylinder. Worked really well for me in several engines.
You could also use nitrile or viton o-rings, if you find a suitable size.