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Drive rods and Walschaert's valve gear

April 17, 2006

One of the reasons I bought this kit was the fact that it contained a complete Walschaert's gear that needed to be assembled completely. I have built kits before, but the only one with a Walschaert's gear had its gear completely factory preassembled. Before starting on really expensive models I wanted to get some practice on riveting the parts together.

Cutting out with a flush cutter
The crosshead should move freely and without binds over its guidance. Out of the box this is hardly the case. I worked on it carefully filing off a little at a time
This is how far it originally got. After filing it down bit by bit it fit at last. Then I sanded the surface of the guidance and polished it to reach an optimal smoothness
The complete gear after cutting and filing and before riveting
The holes of the parts all needed reaming a little.
The proof of the pudding: the rivet should fit in as tight as possible but without binding.
Riveting two parts together. A used my drill stand to exert the power needed. The instruction leaflet shows a hammer. But hammering needs an awful lot of experience to hammer it straight and with just the right force. It also gives the parts ample opportunity to slip away from your fingers and fly sprawling through your room. Using the drill stand I could use the sensitive lever to determine the power and to feel the movement in the rivet. The idea worked extremely well. Apart from the first rivet which I pushed little too hard, all other rivets fit nicely.
The assembled right gear. 3 cm long and almost two hours of hard work!!
The action of the valve gear (left side)