DB has had a busy lately, but has recently been down to the trainroom for the first time since the Christchurch Show...
You may recall that I purchased a sound equipped Broadway Limited Light Pacific 4-6-2 earlier in the year, thinking that it 'looked about right' for an Ab.
So a week ago I decided to look more seriously for the first time at the Ab shell that 3-6 models delivered several months back.
The Ab itself is a decent print. Things look in proportion. The boiler bands are a bit prominent and the diameters of the smokebox and boiler cladding look quite different, but that might be authentic, and anyway, it will all fade away when everything is painted black and a few bits of piping are put on top.
As can be seen, when I pulled apart the Broadway Limited tender, and there was a far bit of stuff in it. All wheels pickup power (as do the drivers on the loco). This is good. There is a multi-wire connector between the loco and tender. The sound decoder and a speaker also live in the tender. All nicely plugged-and-socketed for disassembly.
On seeing this. I decided that an A class might be a better choice, as I might be able to to fit all this back into a scratchbuilt 'box' A tender, but it won't go into a 3D printed Vanderbilt Ab one. The Ab tender print can be turned into a dummy, and hang around inside the Elmer Lane roundhouse.
A few visits to the Dremel in the garage had the underside of the boiler widened out to fit over the motor. It didn't take much effort actually.
The problem was that even with that done, the whole body sits very high (of course!). A few more visits outside had me thinning out the inside roof of the boiler.
Now that is minimalism. The main problem was that the chassis has a tiny white square socket above the middle driver (a socket for the headlight wiring) and a cast 'tray' that carries wires above the brass flywheel. I didn't want to risk disaster by removing these. So I thinned the shell further.
All was going swimmingly until I decided to cut out out a small section of the top of the boiler roof completely, fore and aft of the steam dome, to let the white box and tray sit up into these holes. I'd cover the small holes with paper.
Of course something snapped when I was reshaping the headstock and then the whole thing ended up on the concrete floor! The dome came off, as did the headstock, and the boiler cracked a bit. Bah. At least the little white socket and cast tray can sit up into all those holes in the boiler now, lowering the body onto the chassis to an acceptable height!
The holes have since been patched up. But not that well, mind you.
The A doesn't have the Ab's prominent curvy steam pipes to the cylinders, so these were removed, plus the other details (makers plate etc) on the smokebox beside these.
I think I'll leave the loco here for me to calm my nerves!
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Instead, lets take a serious look at the tender. Maybe that will be easier. And its really important because of all its guts. Being an American prototype, it's a lot longer than ours. With our much lighter axle loads, we couldn't carry nearly as much water and coal around.
The cast floor has bogie mounts and a coupler, plus the attachment clip for the loco drawbar, so I thought I'd preserve these features by simply shortening the floor. After unpluging the speaker and decoder, a few semi-careful slashes with a Dremel cut-off wheel had the black chassis ready to be snapped into three, with the centre bit then discarded.
There are three 'levels' of stuff inside the tender. On the bottom are wires from the bogie pickups and the attachment for the loco drawbar. I've had to add some supporting steel rods as well, to hold my two chassis halves together.
In the middle is the DCC/Sound chip.
The speaker is on top. All these pieces are nicely plugged-and-socketed for easy detachment. The speaker is nicely shaped to fit inside the tender, creating a snug soundbox.
I wanted to preserve this clever design work, as well as the idea of a removable tender-top so that everything can be easily disassembled if there are any issues in future.
After more pondering, I figured that the supplied tender top isn't a million miles off the shape of an A tender anyway, so I'm adapting it by lopping a bit off the back to shorten it, and building the coal box on top. Yes, the 'curved top wings' are a little high and should extend further back, but nothing a galloping horse would notice.
So the challenge is now, how to fit the guts back into the shortened tender (I subsequently decided to extend the tender chassis by about 2mm from what I had cut it down to). It's going to be a very tight squeeze.
Top fits on the shortened chassis. Speaker to be shortened:
The speaker was relatively easy. I prised off the PCB with the socket, cut the PCB down, and relocated it on a shortened base. In doing this, it wouldn't fit easily, and I eventually broke the solder join between one wire and the PCB, so attempted to solder the tiny wires to the back of the tiny socket, then glue the remainder of the PCB onto the shortened speaker tray.
I then thought I'd better see if all this work has damaged anything by plugging things back together and giving them a run:
Good heavens. Its still runs and makes noises.
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