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Motion problem

No motion in forward gear

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David Bothwell 111/01/2017 12:21:57
78 forum posts

Working on a three and a half inch gauge 0-6-0 "Molly" I bought part built. When I acquired it it was running in both directions but there were no connnecting rods fitted. I have now fitted these. The engine ran OK as I was very careful measuring for the holes (they were laser cut rods) however after a few runs the eccentrics were found to have moved and were loose. So I drilled and pinnned these. Since then the engine will only run in reverse!? I also noticed when I first (acquired) ran the engine the reverse lever seems to be the "wrong way round" i.e. when pushed into forward the engine runs in reverse. Any suggestions gratefully received. I should add the right hand eccentric (viewed from the back of the engine) is 90 degrees in advance of the left.

JasonB11/01/2017 12:34:22
12342 forum posts
1096 photos

Sounds like one or more got pinned in the wrong place, How are the eccentrics positioned in relation to the crankpins, they should lead by 90degrees and a bit more so say 100deg to start with

David Bothwell 111/01/2017 13:36:36
78 forum posts

I never altered any settings of the eccentrics, so I assume they are in the same position as when the engine arrived, but having said that something is definately amiss!

Chris Gunn11/01/2017 17:26:18
241 forum posts
12 photos

David, could you have reversed the eccentric rods to connect to the wrong ends of the expansion links?

Chris Gunn

David Bothwell 111/01/2017 19:53:39
78 forum posts

Hello Chris. many thanks fir your input, I thkink you may be right, unfotunately I would have to drill out the pins I have inserted to put it right. Am I right in thinking you mean to turn the eccentrics180 degrees? On the drawings I am sure it said right hand eccntric leading the left by 90 degrees(whis is now where they are), but will check thisin the morning

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