slip eccentric

[JMORG]

Hi guys!
As some are aware, I am building a model of Moel Tryfan. It's temporarily on hiatus due to my old man making 2 Garratt locomotives (similar to the Rachel tiny Garratt), but will restart afterwards.
After looking at the Roundhouse valve chests, I have concluded that new valve chests will be made (based on wild rose).
The slip eccentrics are causing sleepless nights due to the relative complexity. I have an excellent book buy Mark Horovitz describing loco building and he mentioned castings for the eccentric straps.
Does anyone know of a company that might do these castings?
Apart from that, small details have been made (chimney, Salter safety valve, air reciever ect) along with the wheels and the rear bogie. Work on the frames is the current job!

[DVT Dweller]

Could you not get the straps laser cut from steel instead of casting?

[kandnwlr]

Could you not get the straps laser cut from steel instead of casting?

You might talk to Stewart Browne of Archangel, who is an expert on slip eccentric mechanisms, and has been doing this stuff for ever.

[Big Jim]

Have a look at Dave Watkins live steam site.

http://www.davewatkins.pwp.blueyonder.c ... /steam.htm

There are some plans for Wild Rose and a links to a blog about how he is building it. Including some bits about slip eccentrics.

[GTB]

Does anyone know of a company that might do these castings?

Castings for slip eccentric straps were commonly used in the past for Gauge 1 locos., such as those designed by LBSC. Peter Jones has photos of them in his steam loco book.

Model engineering suppliers like GLR Kennions, Reeves(2000), etc. would have supplied them in the past and possibly still have suitable G1 castings.

They aren't particularly difficult to fabricate though. The Wild Rose 111 design previously mentioned is a simple design. Castings are usually pretty crude and by the time you finish setting them up and machining them, it's almost as much work as machining a set out of a piece of suitable size flat bar.

See Dave's page at http://wildrose16mm.blogspot.com.au/201 ... traps.html

The reprint of Brian Wilson's book is due out soon and he has a design in there for a slip eccentric valve gear that is easily fabricated.

I think the G1MRA Project design also uses fabricated eccentric straps and might be worth a look. Someone may do castings, as a lot have been built.

Regards,
Graeme

[LnBmad]

cannot recommend 'model steam locomotives - by henry greenly' enough if your trying to understand how to make valvegear of any description.

the machining of slip eccentrics isnt hugely complicated, the designing just takes a bit of thought is all.

[JMORG]

Thanks everyone!
It's all good suggestions and food for thought.
I promise to post pictures once work restarts