Bassett Lowke 3/4″ Scale Traction Engine – Cylinder and Motion Assembly

The photos show the traction engine with the Crankshaft, Connecting Rod and Cylinder Assembly mounted on the Boiler.

The Cylinder Assembly comprises, Cylinder Saddle, Cylinder, Valve Chest and Cover, Piston and Rod, Crosshead and Trunk Guide.

Here is a gallery of photos:-

Intricate Parts & Delicate Machining

Makin the components for this cylinder assembly has been very interesting with intricate machining and very accurate setups needed. Particularly so because the tolerances are so small on such a scale scale model.

On a large model, bearings, for example, to take shafts or other moving parts are often made with say a 6 ‘thou’ clearance (typical on my 1/2 size Little Samson Traction Engine), but at this 3/4″ scale I make these parts with no clearance or as tight as I can get e.g. using reamers, and then they are lapped to fit (if needed).

The same situation applies to setting out. I always blue the parts and mark out as normal but these would just be guidelines. All setting out distances have been measured using the DRO on the milling machine.

I hope to post some photos of the machining operations in another post. Here are just a couple of photos to whet you appetite for the other photos.

 

Next Items to Make

Of course, that Cylinder Assembly is just the main components, there being many more items to make and add next, primarily the valve gear:-

• Eccentrics
• Eccentric Rods
• Reversing link and lifting gear
• Slide valve and Valve Rod

Plus the ‘plumbing’ meaning the steam supply and exhaust piping, passageways and fittings. (Lubricator, Regulator etc)