Making a Stephenson’s Link for a triple expansion steam engine
Progress on the triple has slowed lately, partly because I am spending spare time on the Colchester lathe commissioning, but mainly because the plans for the Bolton 9 triple expansion steam engine are fairly vague and hard to interpret with respect to the Stephenson’s link reversing mechanism. I think that I have finally got my brain around the workings of the mechanism, partly thanks to the many Youtube demonstrations, but mainly thanks to a series of articles in “Model Engineer” in 1985 -6, to which a colleague directed me. (thanks David).
The author of those articles has taken the trouble to document improvements to the original OB Bolton plans, and the improvements are much more comprehensible. (unlike this blog.)
My uncertainty was compounded by finding castings missing from the kit of parts which I had purchased. I had taken the precaution of taking photographs of all of the castings when they were originally unwrapped, so I know that they were never there. The supplier was not interested in rectifying the problem, so I am making the parts out of brass bar stock.
The following photos are the situation to date.
I will machine the yokes next week some time. Space ships found in the Kazakhstan desert much more interesting, no?