Machining Stuart Turner No.5A Engine Reversing Gear.

[robert winstanleyParticipant @robertwinstanley43030]

Would be grateful for any advice on the best way to tackle machining the double eccentric casting for this steam engine. Also any tips or things to be aware of for the remaining castings. I'm trying to avoid too many disasters.

I have just received the full set of castings from Stuart.

l have a Myford.

Thank you.

[robert winstanleyParticipant @robertwinstanley43030]

Machining eccentrics

[Sub MandrelParticipant @submandrel]

Hi Robert,

If you are mainly worried about getting the angle between eccentrics wrong, then I'd machine them as as one long 'eccentric' then part it into two pieces and pin them together when you have the angle right.

Neil

Edited By Stub Mandrel on 03/07/2013 19:05:35

[JAParticipant @ja]

Many, many years ago I started making a Stuart Turner 7A engine with reversing gear (about half the size of a 5A) which was put aside when life got more complicated. Before being put aside I managed to break two eccentric castings while machining them (cast iron).

Recently I have been bullied into finishing the engine which I am now doing so between other projects. I turned the double eccentric out of mild steel using a four jaw chuck to produce the offset. The job was not difficult but you have to think about what you are doing.

I remember having problems machining the eccentic rods which, being made of gun metal, were rather flexible. At present I am producing the linkages of the reversing gear using files and filing buttons since I had little success milling them out of strip. You may not have such problems on a larger engine.

JA

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