jamiepage
Western Thunderer
I've long been interested in 7mm live steam, and in fine scattergun tradition recently pushed aside a couple of other projects and made a start.
One of the real experts in the field, Clarry Edwards, described in MRN, Feb 1961, a live steam M&GNR 4-4-0. Full of good tips, the article showed his idea of a separate cylinder/ crank axle unit which could then be fitted within a one piece cosmetic frames/ footplate/ superstructure unit.
A sort of steampunk RG7 idea really.
The M&GN 4-4-0 used a single cylinder with 2:1 gearing and I have followed suit.
First job was a cylinder block, machined up from a nice piece of bronze.
Rather than a conventional slide valve I took the idea used in the G1MRA ARM1G design with a circular section steamchest and valve. I do not think I've ever had an original design idea, but am very grateful to the true engineers that do come up with these ideas).
Some careful drilling with 1.2mm steam ports and 2.2mm exhaust way joined the relevant bits up.
(The slide valve is sitting upside down in this photo)
Screwed glands for both piston and valve rods were fitted to a one piece back plate. A plain front plate and top plate with angled steam inlet and blastpipe completed the block.
Two 'mainframes' were cut and drilled, then fitted with bearings for both crankaxle and driving (wheels) axle after which the crankaxle, crank etc could be made up and tried for size.
One of the real experts in the field, Clarry Edwards, described in MRN, Feb 1961, a live steam M&GNR 4-4-0. Full of good tips, the article showed his idea of a separate cylinder/ crank axle unit which could then be fitted within a one piece cosmetic frames/ footplate/ superstructure unit.
A sort of steampunk RG7 idea really.
The M&GN 4-4-0 used a single cylinder with 2:1 gearing and I have followed suit.
First job was a cylinder block, machined up from a nice piece of bronze.
Rather than a conventional slide valve I took the idea used in the G1MRA ARM1G design with a circular section steamchest and valve. I do not think I've ever had an original design idea, but am very grateful to the true engineers that do come up with these ideas).
Some careful drilling with 1.2mm steam ports and 2.2mm exhaust way joined the relevant bits up.
(The slide valve is sitting upside down in this photo)
Screwed glands for both piston and valve rods were fitted to a one piece back plate. A plain front plate and top plate with angled steam inlet and blastpipe completed the block.
Two 'mainframes' were cut and drilled, then fitted with bearings for both crankaxle and driving (wheels) axle after which the crankaxle, crank etc could be made up and tried for size.