Charlie Dockstader' Simulator Program

Would somebody who is familiar with the use of Dockstader's simulator advise me how to eliminate the effect of the rocker arm in the Stephenson's Outside Admission progam.I have tried setting the rocker parameters to zero but this only brings up an error message. I have also tried setting one arm to a positive number and the other to a negative thinking that this might cancel the effect of the arm , but this also gives an error.

I am trying to study the set up of the valve gear of my 5" gauge IoW O2 loco that Ihave under construction.

Malcolm Hearne

hi malcolm,

ive sent you a belated pm!

cheers,

julian

Hi Malcolm,

This one is even more belated!!!

I'm fairly sure you will have moved on from this now. I still don't know the actual answer to your question, but I do remember you asking it. I also remember thinking that the trouble with the Dockstader software is that it isn't very interactive. IF it has a layout for the gear you are interested in, then it can give SOME help.

I've been attempting analysis of valve gear on an engine and searching for new (free) software to simulate 2D kinematics. I've come across this software for "Windoze" called "Linkage"......

**LINK**

This version has not been out long, and I've never seen it before. It has been designed to do any system of links, slides, pivots, gears and pulleys. I've found some situations where it can't calculate a geometry which ought to be physically possible. Generally though it's much more usable than the Dockstader software.

It has a bunch of examples built into it, and one of them is Stephenson's gear. Most of the examples are simplistic, or weird things like marble launchers.

The only thing I think that the Docstader software has over it, is steam diagrams and plots of the valve events. I'm still experimenting, but you might find inventive ways to achieve the same ends. In any case if you want to experiment with the overall geometry of a valve gear this is certainly worth a look.

Hope the O2 is going well...... (I guess you probably finished it by now!)

Andy.

You could try Bill Hall's program at **LINK**

I don't know whether it works in modern Windows, if not run it in a DosBox

I supplied all the corrections to Malcolm 3 years ago for the Don Young 5"g O2 Fishbourne design, but I would echo Duncan's comments on the Hall simulator. It is always my first starting point these days.

Very easy to use.

You just need to be aware of certain limitations and the automatic equalising of leads which is something neither Don Ashton of myself agree with with Stephensons gear.

Cheers,

Julian