Monday, 4 May 2009

45xx progress

I suppose one of the few benefits of a wet bank holiday is the extra modelling time it affords!

I made a new baseplate along the same lines as the previous one (as it had been hacked about a bit). I used the Bachmann pickups (I ordered a couple of the baseplates direct from Bachmann specifically for butchering). I cut the middle section out of each pickup strip (to prevent any interference with the centre axle) making two short strips for each side - one with a single wheel contact and one with two contacts. These were araldited into place with the wheel contacts protruding through the existing locating holes in the sideframe mouldings. I needed to electrically re-connect the two pickup strips on each side so, to avoid fouling the centre axle again, I drilled small holes adjacent to each section of pickup strip and then bent a length of thin copper wire so that the ends were flat on top of each piece of strip, passed down through the baseplate and ran along the underside, one wire on each side obviously. I should have said that before aralditing in place the top surface of each pickup strip was tinned with Carrs 188 degree solder paint; the ends of the copper wires were also tinned. Then the wires were soldered to the pickups using Carrs Speedy solder (with just a drop of flux). At the same time, thin sheathed wires were soldered on, to connect to the motor.

Once all this was done I temporarily fitted the gearbox and motor, connected the wires, and checked it all worked. Bingo! However, a couple of issues presented themselves. The middle wheelsets had too much vertical movement so that it was possible for the gearwheel on the axle to disengage with the gearbox. A couple of slivers of 0.5mm plasticard added to the top surface of the baseplate immediately under the centre axle quickly fixed this, still allowing sufficient movement (to act as a poor man's compensation) but ensuring the gears stayed interlocked. Also, and more mysterious, it wasn't actually moving! The chassis was remaining stationary while the centre wheels simply slipped, unless I applied some downward pressure in which case it did move, which suggests it was to do with the lack of weight from the body - although the unaltered Bachmann chassis ran perfectly well without the body...... hmmmmm, one to investigate further!

Anyway, putting that aside for another day, I did a bit of tidying up of my cosmetic sideframes using some Humbrol filler to get rid of a few gaps along the top edge and added some 'packing' along the bottom edges using strips of plasticard (which will be filed and sanded once fully hardended) to ensure there is as little gap as possible when the baseplate fitting is attached.

I'll get there eventually!!

1 comment:

  1. Hi Matt,
    could appreciate images of your solutions re pickups. I built a P4 Gibson Black 5 a couple of years ago, and made rather a pigs ear of that part of things. At near bottom of page, there's some pretty neat looking solutions, fyi, though sounds like you've worked out your own.
    Thanks for your blog, much enjoyed especially the Betjeman film.