mikeg Posted March 17, 2019 Share Posted March 17, 2019 I have a Hornby MN loco that has badly damaged valve gear, neither Hornby or Peters Spares have replacement units, does any one make an etch that I can use to replace the existing. I tried to repair the existing but the crosshead casting casting broke and the pins in the drop links bent when I had repaired one side. The original problem was that the connecting rod joint with the crosshead had sheared off on both sides. As the crosshead and valve gear is unique to this loco in the Hornby range and I doubt if I could make it from scratch, I think I remember that someone made an etched kit that maybe I could use the valve gear to repair my loco. thanks in anticipation of an answer mike Link to post Share on other sites More sharing options...
Yardman Posted March 18, 2019 Share Posted March 18, 2019 Most model valve gear's are a poor Most model valve gear's are a poor representation of the real thing. Comet do kits for various locomotives that could possibly adapted to your use. These are what I adapted for a Hornby B1. 2 1 Link to post Share on other sites More sharing options...
mikeg Posted March 18, 2019 Author Share Posted March 18, 2019 Thanks Yardman, I will have a look at the Comet site. Regards mike Link to post Share on other sites More sharing options...
RMweb Gold Right Away Posted March 18, 2019 RMweb Gold Share Posted March 18, 2019 1 hour ago, jf2682 said: Nicely made! Can the gear be modelled in different cut-offs? Maybe one day we'll have decoder operated radius rods in sync with direction of travel - just a silly thought. 1 Link to post Share on other sites More sharing options...
DCB Posted March 18, 2019 Share Posted March 18, 2019 3 hours ago, Right Away said: Maybe one day we'll have decoder operated radius rods in sync with direction of travel - just a silly thought. Should be possible to create something mechanical to make the gear run forward in forward gear and back in back gear but actually making the die block etc work might be a step too far. Link to post Share on other sites More sharing options...
RMweb Premium Barry O Posted March 19, 2019 RMweb Premium Share Posted March 19, 2019 Already done in O Gauge. Although it's not fully automatic, you can use a servo remove the gear from forward to reverse using a playable function button. Baz Link to post Share on other sites More sharing options...
Yardman Posted March 19, 2019 Share Posted March 19, 2019 14 hours ago, Right Away said: Maybe one day we'll have decoder operated radius rods in sync with direction of travel - just a silly thought. Yes you can make it up with different cutoffs and should be possible to have servo operation of the reversing gear, but it would be fiddly in 4mm and is it really worth the extra complexity. Most people would never notice it. This is the completed B1. 1 Link to post Share on other sites More sharing options...
Il Grifone Posted March 21, 2019 Share Posted March 21, 2019 (edited) On 18/03/2019 at 18:48, Right Away said: Maybe one day we'll have decoder operated radius rods in sync with direction of travel - just a silly thought. It was done in S scale many years ago. IIRC a small motor drove a screw to reverse the gear on changing direction. Most 4mm models are set in mid-gear though Hornby Dublo set theirs in forward gear (apart from the 4MT 2-6-4T which is in reverse). Many models have the return crank wrongly set which makes the whole exercise pointless. Proper locomotives have the gear between the frames, so it's not a problem. (Ducks for cover....) Edited March 21, 2019 by Il Grifone Link to post Share on other sites More sharing options...
RMweb Premium Nile Posted March 21, 2019 RMweb Premium Share Posted March 21, 2019 It's been done in 2mm scale, in a 9F. I think it was in MRJ not that long ago. Link to post Share on other sites More sharing options...
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