"Dashpots" on a Corliss engine.

[Philipintexas]

I'm nearing completion on a multi-year Corliss project and have a couple questions about the function of the dashpots. I assume they pull a vacuum when the valves open and the vacuum pulls the valve closed when the grab-claw releases. Why was this method used as opposed to a spring or even a hanging weight? I'm ready to make mine but don't know if the original method would work in miniature. Has someone built them with lapped bore/piston? and does this work over time? Thanks.

 

[arnoldb]

Hi Philip

First off, Welcome to HMEM

You're correct about the function of the dashpots as far as I'm aware. On full-size Corliss engines they used dashpots, as these could be tuned to easily control how much pull they would exert and how far they would pull. That's more difficult to do with springs. Weights would add unwanted mass to the valve gear assembly - and always be in effect, while the dashpots only affect things more closer to the point where their pull is needed.

Springs would work just fine on a model Corliss - in fact, it appears that most model builders use springs hidden in make-believe dashpots. It all depends on how true-to-life you want your model to be. If you go all the way like Jerry Kiefer did, then make the dashpots

It would be really nice if you posted an introduction in the welcome section - and pictures of your Corliss build

Kind regards, Arnold

 

[tel]

Welcome Philip. I second the request for an intro - and some pics please!