I've been thinking ahead to bogies for the coaches. The Caledonian used Fox bogies for their 48ft stock and there's an excellent GA drawing in the Caledonian Association book on coaching stock so I had no excuse. I still haven't decided whether I will be making a master for casting, or making each part required. I'm intending that the bogie sides are cosmetic and that the bogie will have inner frames to locate bearings and suspension. I'll probably do an etch for the inner parts of the bogie.
The main feature of the Fox bogie was the pressed steel sides with heavy flanging on the top and bottom edges. The radius of this flange was about one inch radius, so is quite noticeable. the depth of the flanges was three inches.
I opted to cut the side from 3mm styrene on the CNC mill. The styrene was cut down to 2.4mm to get to the scale three inch depth and the outline was cut, and pilot holes for all the river holes drilled. the curved flange edge was then machined using a ball ended bit and a bit of hand coded GCode.
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The various plates to fit on the side were cut from .75mm styrene surfaced down to 0.6mm to get the 3/4" prototype thickness.
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A slightly tighter shot showing the machining of the curved edge. All the pilot holes drilled on the CNC mill have been opened out with a 0.8mm drill to suit the brass rivets I have.
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This is the first plate being placed using the brass rivets through some of the holes to locate it before stickign it down with Mekpak.
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The side with all the platework in place and most the rivets inserted. the holes for the footboard supports - like the two at the left - have been left till the footboards are fitted much later.
I'm not sure about the 1/32" brass rivets. Their size is about correct but I think that they might be just a bit too prominent. They might look better after getting a scoosh of primer or I might have to look for an alternative. I might try getting some scale 7/8" G scale Archer rivets or I might try George Slater's rivet method, applying heat to the end of plastic rod to get a mushroom head effect. This only works on the old Slaters red/brown rod and I might have enough of it left to do the job. It would need to be the 30 thou size. My only reservation with this method is getting the heads to be the same size since the size can vary depending on the time the heat is applied and the distance from the heat source. I no longer smoke so I can't use George's heat source of choice, but I now make do with a candle flame.
Jim.
Hi Jim. Just in case you've forgotten there's a list of fastener sizes on WT. Search for 'Fastener sizes and scale equivalents'. The sizes, diameters, heights etc. are given in Gauge 1. Hope this helps. G.