Making the Beam for Lady Stephanie

[geoff]

I`m in the process of building Lady stephanie Beam engine by Tubal Cain and have decided to make as many parts as i can from scratch as i`m not impressed with the quality of the castings supplied by Reeves. I`m working on the beam which has a curved shape with a radius of approx 550mm and i will try to make a pivoting sub table for my mill, but is there a better way? You think there`s not much to it untill try it out for yourself. I have added a picture of a completed engine by Rob Dunster on flikr.
Have any better ideas.
Geoff

 

[Jasonb]

I think I would just saw the internal web to approx shape and then sand down to the line on the linisher. Then wrap a strip of steel or brass around the outside and silver solder the two together adding the bushes for the various pivots at the same time. It can then just be treated as a "casting" no need for a perfect curve to the outside and its probably eliptical anyway not a perfect arc.

The bead along teh centre line can be soft soldered on using bras half round beading.

J



J

 

[peatoluser]

when Tubal Cain designed the engine, he didn't use castings either, but fabricated everything. I think it was serialised in the early editions of 'Engineering in Minature' . May be worth tracking down some copies? If you can't, in the book he wrote 'Soldering and Brazing' he uses the beam, eccentric rod and top entablature from this engine as examples of step brazing.
The beam was made pretty much as Jason suggests.
The beam is drilled for the bosses. The bosses turned up, one with a spigot to go through the beam, the other with a hole to locate it.
These were silver brazed, the outer web was soft soldered (using a 185C-225C solder) and the thin central web, made from half round brass strip, was tinned (as was the beam) with an electronic grade solder (183/185C), an electric soldering iron being used for both soft soldering joints.
Good luck with the engine. I seen one running at Harrogate this year. It really is an elegant design.
By the way, even if you can solder and braze, I would still heartily reccomend the book 'Soldering and Brazing', as it deals solely with 'our' type of jobs, and contains all the information you'll probably ever need.

yours

peter

 

[geoff]

Thanks Peter & Jason
I never thought of building up the beam this way i will have to give it a try as my method is a bit risky.
sounds like a usefull book, i have a couple of others from the series and they are good value.
i find you can`t rush a project like this as theres lots of learning to be done. I will post some progress pics.
Geoff