This week is proving to be fairly productive with three locos on the workbench at various times. The excellent weather over the Easter holidays has enabled me to spray two locos built over the last eight months and get the 76XXX into top coat to enable completion of the build to start. All were given time to bake in the conservatory between coats.
The Crosti 9F is now waiting delivery to its owner.
Exhaustive testing on Heyside identified a major short on the fireman's side between the intermediate and fourth axles. This occurred regularly at just one location on the layout and foxed me and others especially as there did not seem to be any obvious metal to metal contact. Eventually the problem was identified as being the drawbar, it was too broad under the cab, was restricting side to side movement and the entire loco went rigid when passing through a point. Some quick work with a scalpel and it ran perfectly albeit requiring more running in. This build was started in September 2014 and has taken about 5 months overall to complete.
The Chowbent Stanier 2-6-2t had to take a back seat while replacement split axles were sourced. The original ones fitted to the loco collapsed causing quite some consternation for Clive who produced them for me! The problem was tracked down to old/stale epoxy resin.
With the new axles fitted the valve gear was installed and tested on a rolling road. Minor adjustment was required to give a little more clearance for the return cranks but otherwise it ran smoothly or so I thought. Further testing on Heyside has shown a lack of side play on the middle and leading axles. This has necessitated stripping down all of the valve gear, connecting and coupling rods to release the wheels. On the leading axle the very thin spacers have been reduced even more to give additional clearance. On the middle axle the axleboxes have required filing down to give more side to side play, 0.5mm on each. This axle was held almost rigidly in place by the gearbox which just fitted between the insulated axleboxes supplied by Slaters. I thought there was sufficient movement but was proved wrong. Another test run is now in the offing and providing this work has given sufficient additional flexibility then the finer paint details can be tackled. Hopefully it will be off for lining and weathering in the next 14 days.
The MOK 76XXX is progressing steadily and all the major components are in top coat black.
Work is now concentrated on the engine frames with all springs installed. It was my intention to fit plunger pick-ups in line with the instructions but found it impossible to install the etches for the rear drivers. The fitting details are at the very end of the chassis build instructions and frankly these parts need to be put in place during the build up of the frames. The components in question were to be fitted under a crossbeam next to the steam brake cylinder, just under and either side of the bolt on the right shown above. There is next to no room to manoeuvre the parts let alone hold them in position. Four wheel pick-up is out of the question so I have fitted wiper collectors to two of the tender axles. This has slightly compromised the compensation but on test everything seems to be fine. The two wires when painted black will double up as the vacuum and steam heat pipes.
Once the pick-ups have been installed I can refit the wheels, motor and connecting rods and start to build up the valve gear. Unfortunately the paint on one cylinder is not acceptable so this has been be stripped and resprayed. Slow but steady progress might see the loco finished by the end of the month. Then it's back to the Standard 2-6-2t; yes Iain Young has found the missing etches for me!
With the screen behind the drivers position and the narrower one behind the fireman's in place I tackled the roof and was able to create the required radius quite easily.
This is the usual DJB bodge being 4mm too wide at the front and overall 2mm short adjoining the cab front! To overcome the width problem I cut out a long V, pulled the etch into line and soldered the new join, strengthened with a nickel silver strip inside. The holes for safety valves and manifold were also re-drilled but before I found the 2mm discrepancy! So now they will have to be moved back, one step forward, two backwards comes to mind!
