CF MRC

Mike Randall, a major contributor to the construction of Luton Hoo and Copenhagen Fields, has died from complications arising from his cancer treatment. Mike was well known in 2mm scale modelling circles and was responsible for all the plywood engineering that makes up Copenhagen Fields, with perhaps the most impressive feature being the 22’ span proscenium arch that takes the layout lighting and frames the scene.

Mike was a major contributor to numerous MRC projects and pursued multiple interests outside of railway modelling with never diminishing vigour. He will be greatly missed by us all in the Model Railway Club, having given a great deal over the last 40+ years, based of his encyclopaedic knowledge and skills in timber and building construction.

Tim Watson

I couldn’t really resist continuing with the Westinghouse pump, so it now has the compressed air pipe fitted and the basic fittings for the steam feed and exhaust. 

The feed pipe fitting was made from some 0.5mm OD brass pipe, soldered into the groove cut in to the back of the steam cylinder. This did not have a large enough bore and so it was reamed out using an 06 endodontic file. These are the smallest used in root canal treatments and are made from nickel titanium alloy. The size represents 0.06mm diameter  measured 1mm from the tip. 

The video clip shows it in action. 

The regulator on the LHS is next to be added and the pipe work can be seen here as a piece of 33swg phosphor bronze wire. 

Having this running plate unit as a separate sub-assembly has made it much easier to work on. Apologies if this post relives dental memories for some!

Tim
 

After a few hours of fiddling, the basics of the Westinghouse pump on 2400 are now complete. The steam supply & exhaust plumbing will probably be made later, the air delivery pipe rather sooner.

A 2.3mm diameter blank for the cylinders was turned and centre drilled 0.4mm over 5mm depth. Drilling such a deep hole is taken very carefully, with many clearance removals, aided by RTD cutting fluid, and sharp TC drills.

The blank was then finish turned with a graver, giving the raised ends to the cylinders. A piercing saw was used to separate the two cylinders, also making the stuffing box at each end.

A conventional 0.4mm diameter steel drill shank was used to align the cylinders and a U shaped piece of brass (box section 1.6mm square with a side removed) inserted between the two cylinders - this represents the casting that holds them together on the real thing. The assembly was anointed with silver solder paste and pinned into a stable relationship with old drill shanks thrust into the charcoal block. The whole assembly was gently brought up to red heat for the solder to flash. On a very fine and small component such as this I turn off the workbench lighting so that I can gauge the temperature more easily.

After pickling in citric acid, a few holes were drilled in the cylinders for the shuttle valve and oiler on the top, compressed air outlet pipe and a slot cut on the back for the steam inlet and exhaust pipes. The drill shank is a very useful handle to hold this rather titchy component.

The mounting bracket on the running plate had been fitted previously (with two holes drilled in it) and this was augmented by a couple of pieces of brass wire which were threaded as one U shaped staple from behind and soldered in place. The excess wire was cut off and dressed in front and behind to neaten them up. 

These two pegs represent some substantial brass bolts in this area and made it easy to locate the pump for soldering to the bracket: the drill shank had previously been sliced off with a diamond disc. Having the main pump silver soldered ensured that it didn’t fall apart when attaching it to the locomotive. 
(photo courtesy Owen Chapman)

The final result needs to fit very close to the boiler as the hand rail takes a detour round the top of it! The extra bits for the pump will be made when the associated plumbing is fitted.

The piston is scarcely visible - like the real thing - but at least I know it’s there. The Association makes a 3DP version of this which is very fine, but I prefer turned metal in this situation. The 3D metal print looks a bit ‘hairy’.  Quite crazy really, as the whole thing is only 6mm tall. 
 

Tim

Some more progress on the Skittle Alley today. 

The representation of the prototype frames between the splashers have now been fitted. These were made by soldering a strip along the back of the splashers and then cutting out the unwanted bits with a piercing saw; finally tidying up with a bur, so saving fiddling with small pieces. 

The next item was the bracket for the Westinghouse pump. This  was a very substantial casting in real life.

The next photo is of a prototype made with a (too) small brass T section. The end piece is folded over and the junction with the upright pillar flooded with silver solder paste and gently heated to flash into the crack, so making a strong assembly. 

The definitive bracket was made from 3mm brass T section, filed down to size (approx. 2mm wide) with the foot silver soldered in place. A long handle was retained for holding during construction and positioning the bracket on the running plate whilst soldering: I use this technique a great deal for stabilising small pieces during assembly.

The top had been partially cut through so that it simply needed twisting to remove the handle.

I have a cunning plan for making the pump…

Tim

I have been working on the splashers for the Raven NER 4-6-2 class over the last few days.  She’s beginning to look a bit more racey, with the wheels covered in a bit.  

The brass disc blanks were turned from a lump of brass in the Myford 254. The front face of the splashers, including the brass rim was finshed on this lathe as can be seen:

Five discs were made and parted off. One as a prototype and two were used. 

The discs were mounted in a step collet on the watch maker’s lathe and hand finish-turned using a graver. Important to note that the graver is held with a pen like grip so that should it ‘catch’ then it flies from your grip, not through your hand. 

The thickness of the splashers was checked using a thickness gauge, which Jim will recognise.

Once happy with the proportions the splashers were cut off as chord segments with a piercing saw. The tops of the running plates were made from 5thou steel, with suitable clearance notched for the wheels. The splashers were rebated at each end so as to locate on the steel when soldering into place.

The engine has a Westinghouse pump on the RHS: that should be fun…

Tim

I had a really fun time at Ally Pally with the YR diorama last weekend. It was great to have visitors being able to get really close to the model to actually see it! The interest in underground modelling is clearly developing and I spent some considerable time showing individuals historical images and also construction images using the iPad. These have now been ordered into logical albums, which will also simplify giving talks. 

Back to the Skittle Alley.

Tim

One of the Grove’s locos had obviously sustained a fall and had a badly mangled chimney.

This has been screwed on to the smokebox and had a made-up saddle, with a filet of solder around the base. The brass chimney did, however contact the smokebox. Fortunately, it was easily removed from the loco and a brass dowel plug turned to fit from the base up to half the height of the chimney: it was then Loctited in place.

The chimney top was then parted off from the base, but retaining the plug. I often use a piercing saw blade for parting off, these days. It is very precise, and makes very little kerf.

A replacement top section was then turned up with a central hole to fit the plug. A graver was used for fine turning.

This was then parted off and offered up to the base.  

Once Loctited in place, the chimney was finish-turned to the same dimensions as the original.

The chimney was chemically blacked, Araldited in position and painted satin black to match the rest of the engine,

Quite a long winded description of a fairly challenging little job. Should be ready for Ally Pally on Saturday.

Tim