Runner
Well-Known Member
- Joined
- Feb 10, 2011
- Messages
- 124
- Reaction score
- 17
Hi all,
I am making a 3.5" gauge 2-6-0 locomotive based on LBSC's "LMS Black 5". It deviates from his design due to the fact that when I started it I didn't have the drawings or build information, I was using photographs of the model locomotive available on the internet. Hence the measurement between the front driving wheels and the bogie is a 1/4" greater than LBSC specified and the mainframe height is 75mm (2.95275") instead of 3.1875". This 1/4" difference had a ripple effect on the length of the guides, piston rod and piston valve rod. Also, his design is predicated on the use of castings and as far I am aware only available in the UK, so postage to Oz would be prohibitive. Hence I have used only castings for the wheels and hornblocks, which are available from a supplier in NSW. In addition I do not have any milling capability so everything that cannot be machined in the lathe is either fabricated using hacksaw, files and silver solder. I am particulary pleased with my fabrication of the cylinders which utilise piston valves. These consist of two gunmetal cylinders with flats machined on, silver soldered together and then silvered soldered to a brass fabricated assembly used for bolting the cylinders to the mainframes. A third gunmetal cylinder for the piston valve liner is soldered in the upper cylinder. Note my use of a separate guide fixing point on the rear facing cylinder covers. Also the gland retainers use a bolted-on type instead on a threaded gland nut. I just can't get gland nuts to be concentric with the mating thread in the cylinder cover.
I am some time away from getting it to run on air, it's still tight. The wheels with their coupling rods turn freely and the connecting rods with their crossheads in the guide bars run OK. The pistons in their cylinders are pretty well free although the gland packing on one is a bit tight but not excessively so. The tightness occurs when the piston rods are connected to the crossheads, there must be some slight misalignment within this connection as to cause the crossheads to bind in the guides. A bit of fettling is required, but I shall delay doing this because I am going to strip it down for painting. After stripping and rebuilding there is a slight difference to the previous assembly so as to cause binding again. If I wait until after painting I am only going to do it once.
Brian
I am making a 3.5" gauge 2-6-0 locomotive based on LBSC's "LMS Black 5". It deviates from his design due to the fact that when I started it I didn't have the drawings or build information, I was using photographs of the model locomotive available on the internet. Hence the measurement between the front driving wheels and the bogie is a 1/4" greater than LBSC specified and the mainframe height is 75mm (2.95275") instead of 3.1875". This 1/4" difference had a ripple effect on the length of the guides, piston rod and piston valve rod. Also, his design is predicated on the use of castings and as far I am aware only available in the UK, so postage to Oz would be prohibitive. Hence I have used only castings for the wheels and hornblocks, which are available from a supplier in NSW. In addition I do not have any milling capability so everything that cannot be machined in the lathe is either fabricated using hacksaw, files and silver solder. I am particulary pleased with my fabrication of the cylinders which utilise piston valves. These consist of two gunmetal cylinders with flats machined on, silver soldered together and then silvered soldered to a brass fabricated assembly used for bolting the cylinders to the mainframes. A third gunmetal cylinder for the piston valve liner is soldered in the upper cylinder. Note my use of a separate guide fixing point on the rear facing cylinder covers. Also the gland retainers use a bolted-on type instead on a threaded gland nut. I just can't get gland nuts to be concentric with the mating thread in the cylinder cover.
I am some time away from getting it to run on air, it's still tight. The wheels with their coupling rods turn freely and the connecting rods with their crossheads in the guide bars run OK. The pistons in their cylinders are pretty well free although the gland packing on one is a bit tight but not excessively so. The tightness occurs when the piston rods are connected to the crossheads, there must be some slight misalignment within this connection as to cause the crossheads to bind in the guides. A bit of fettling is required, but I shall delay doing this because I am going to strip it down for painting. After stripping and rebuilding there is a slight difference to the previous assembly so as to cause binding again. If I wait until after painting I am only going to do it once.
Brian
