Edward Thomas - valve gear

In message , Allenb writes

If ET has either Stephenson's or Walschaert's valve gear then perhaps your first stop might be get hold of a copy of the appropriate Don Ashton monograph and run the valve gear dimensions as designed through the calculations in the book.

Also, I believe that there are some 'free-ware' computer simulation programs available. Perhaps someone else on UKRME might be able to give a pointer to one of them.

Mike, ET has Hackworth valve gear. However the Don Ashton monographs do sound interesting. Any idea of where I can get hold of them? Thanks

In message , Allenb writes

Camden or TEE would be my first port of call.

I believe that the Achilles Heel of Hackworth gear is that it is extremely sensitive to the vertical movement of the driving axle - Valve setting must be done with the wheels in 'normally loaded' position and springing must perforce be very 'hard'. Any 'Sweet Pea' owners care to comment?

Don Ashton's books have recently been reprinted by Camden - now in one A4 size book.

I hope to have solved the problems associated with vertical axle movement and Hackworth valve gear on my Sweet Pea by making the rear driving axle rigid in the frames (no suspension movement) and also by replacing the Hackworth slides with a system of links as described by Jack Buckler some time ago in EIM.

Mike H>

Have a look at Gilbert alternative as mentioned by LBSC in Model Engineer Volume 99 Issue 2484 page 699. Unorthodox approach to finding a way around the axle movements. No idea how good it it, but if 'The Man' thought it worthwile to mention. then who am I to argue. GeoffH Norfolk