Having dealt with the work on the locomotive body for a while, it was back to the chassis. The next step was going to be a significant one - wiring in the pickups and the motor. I'm not too proud to say that this step always fills me with dread. Everything else to date in a model locomotive is pretty much "cosmetic" until you can get this bit to work.
I'd already had a couple of pointers on how best to lay out the pick-ups from a chap on the EM Gauge Facebook page - there seemed to be a point last year when there were three 48xx builds going on simultaneously. He had done a very neat installation, fixing to a plastic false floor for the cab. I had spotted one slight flaw with this arrangement though, as there were pick-ups to the tops of the rear driving wheel and the carrying wheel but nothing to the leading pair of driving wheels. I felt that there should be some way to ensure pick-up from all three axles.
I started off by gluing some short strips of copper-clad on top of the sandboxes, between the rear driving wheels and the carrying wheels on each side:
48xx pickups and motor (2).JPG
48xx pickups and motor (4).JPG
48xx pickups and motor (7).JPG
I made sure that I had enough clearance underneath the footplate for these to not foul anything. Despite sitting above the sandboxes, they are up inside the side-tanks and below the level of the cab floor.
Then, to pick up from both driving wheels, I put a small piece of copper-clad behind the frame strengthening plate on the side of the frames between the driving wheels. To do this, I had to cut a small section out of the strengthening plate to make room, and a spot of black paint helped insulate it again afterwards.
48xx pickups and motor (3).JPG
When the locomotive body is fitted, the copper-clad is pretty much hidden behind the footplate steps. It is almost invisible, even without the final painting that I will be giving it with the rest of the locomotive.
The pick-ups themselves were lengths of trusty phosphor bronze wire, bent to shape and soldered to the copper-clad. I used the rear driving wheel to transmit the current from the front driving wheel to the motor. There are separate contacts at the front and rear. Whilst this is not as robust in engineering terms as running a separate wire to feed to the motor from the front wheel, it seems to work, and front wheel collection is a bonus anyway. If it subsequently proves too unreliable, I can always re-arrange matters later.
48xx pickups and motor (5).JPG
48xx pickups and motor (6).JPG
With the pickups in place, there was no excuse not to connect them up to the motor terminals with some jury-rigged lengths of electrical wire...
48xx pickups and motor (8).JPG
48xx pickups and motor (9).JPG
From there, it was just a short step to hook it up to my Pentroller. I use this for DC testing of locomotives before I worry about fitting a DCC chip:
https://www.youtube.com/watch?v=dcFHXub3VN4That didn't seem to run too badly, so the final step was to wire in a DCC chip.
48xx pickups and motor (1).JPG
As I'm not running lamps, firebox glow, or any of the "extras" on this locomotive, I snipped off the extra and unnecessary wires, and soldered it in place to the pick-ups and the motor terminals. The chip itself is mounted, if that isn't over-elaborating the arrangement, on the rear frame spacer and held in place with a couple of small pieces of blu-tack.
Cheers
Paul
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