Thursday 25th June

Worklist:
Engine
Generator room

 After a weeks break and Laurence sunning himself in Dorset, it was just Geoff and Stephen.

Geoff continued with the Tangye engine for the generator room. One wheel was bored to take a bearing and boss. With the bearing still in the lathe, the wheel was heated and pushed onto it and the bearing drilled and reamed. A boss was then turned to reinforce the unit on the 'inside', where the electric drive will be attached.

A connecting rod was then turned in brass. One end was shaped and then filed into a ball-end, to fit into the cylinder. This will take the place of the cylinder and gudgeon joint. The other end was filed flat to fit into the crank space. A hole was drilled for the crank and another for a single 12BA bolt. After splitting the rod, the fixing hole was tapped that the components assembled. Finally, the engine was run in the lathe, to bed the bearings in.

Stephen prepared and assembled some 2.5mm thick plastic sheeting for the walls of the generator room. These will sit on the removable floor panel to make fitting-out the room easier. 

A floor of plastic was glued to the plywood base, and when sufficiently set, the walls were cemented in place. Finally, the voids around the tee nuts was filled. 

Geoff will draw and print all of the walls and floor in due course and these will be glued to the wall panels. The doors and surrounds will be added once the wall coverings are complete.

Thursday 11th June

Worklist:
Point actuators - base plates
Generator engine - crank shaft
Gasifier building - lighting

Laurence completed the holes in the initial baseplate by cutting out the servo 'keyhole'. The servo was fitted and it could be seen that without a full-sized packer, the shoulder of the servo fouls the blades of the micro switches. Packers next time Laurence.

Geoff completed turning the crankshaft assembly on the lathe - a very delicate operation following last weeks failures. The excess material on the crank 'disks' was then successfully removed with a grinding disc in order to minimise vibration.

The crankshaft laid in the engine. Whilst the original would have been forged, for a model of this scale (and a moving one at that), a fabricated crankshaft is a sensible alternative. 

Following on from last week, Stephen decided to opt for the generator room walls and features being built off the newly inserted floor, which Geoff agreed would make modelling the interior much easier (and he'll be doing it). This meant the lighting could be mounted on a single baseplate within the roof.
Some retaining brackets were glued to the top of the wall on one side to locate the 'ceiling' panel. The Christmas tree lights were then located on a board cut to size. The lamps were first taped and then wired in place; initially to test the fitting process, but then more permanent tape was used. This proved useful, as some lights had to be moved to avoid tall obstructions. There are 4 lights in each room, with a 9th poked through into the recess behind the double access doors.

The effect with and without the background lights on was very effective.

Thursday 4th June

Worklist:
Point actuator base plates
Gasifier building
Generator engine

It was a quieter session than usual as all three of us were totally engrossed in our individual projects.

Laurence continued with the aluminium base plates for the new point actuators. Nine are required, so three remained to be made following last week. Stephen had supplied a CAD file of the hole layouts, which Geoff had printed onto a sheet of inkjet self-adhesive labels. When the base plates were finished, the first template was fixed to a plate and holes spotted through. Just before 'closing time', the basic fixing and wiring holes were complete. Full production next week!

Geoff continued with the generator engine, and spent ages carefully planned how to make the crank shaft. He decided on the 'traditional' method, silver soldering two axles into two steel blocks, then removing the unwanted axle sections before turning the excess solder .... Bang! the unit shattered. Plan B - turn the whole unit on the lathe, using a 4-jaw chuck to create the offset and ..... Bang! A second attempt was going well.......

Plan C?

Stephen continued with the Gasifier building. This week, he remembered to fix the external scrubber unit to the baseboard before starting work. This was necessary to check the alignment of the flue/ducts from the internal gasifier to the external units. Once aligned,  the timber frame could be glued in place and the fixing hole for the gasifier base drilled. Drilled it was, extra deep, but it was nowhere to be seen until a hole was spotted in the main electrical connector block! Unfortunately, the wooden support blocks were glued and screwed to the baseboard, so, for expediency, a very long bolt was used to hold the base in place. Everything fitted nicely.

The white timber frame just didn't seem right, so along with the internal floor areas, the whole structure was painted light grey, and weathered.

The raised, floor panel in the generator room was fixed down using 4mm tee nuts, to allow it to be easily removed to fit the engine and electric motor. A hole for the light bulbs (filament Christmas tree lights) was drilled and the connector wires tested for ease of assembly. Some more thought was given to how the lights would be fitted and accessed later, if required. This led to whether the generator walls should be fitted to the removable floor, or to the removable walls. To access the lights, the former is more suitable, but to avoid joins and loss of floor space, the latter is better. TBA.

PS An artiste at work!