The 45xx has been gradually progressing over the last week or so. The chassis now runs ok - simply tightening up the coupling rods sorted most of the issues!
The 'wheel arches' (what else do you call the spaces for the axles in a solid chassis block?!) required a bit of work with a round file to get all the wheels level and in full contact with the rails. Not sure if it was wonky out of the box or if it's something to do with the work I've done on the chassis.
(As an aside - while Bachmann clearly don't go as far as putting any form of proper compensation on their models, there is plenty of vertical 'slop' in the way the wheelsets locate into the chassis, meaning that you have a sort of poor man's compensation as I pointed out before - which I think is fine at least for relatively slow running speeds and well-laid track.)
The 're-purposed' Bachmann pickups seem to be fine. One silly thing that's puzzling me at the moment is how to reconnect the wires from the pickups to the motor so they are still easily detachable if I need to take everything apart again. Ideally I need very small terminal blocks but not sure if you can get them small enough or where from... anyone got any suggestions?
I've made a start adding the brakes (the original mouldings were removed from the Bachmann baseplate before it was cut up for use in the new baseplate - if I'd just left them on they would have stuck out too far). I cut small strips of plasticard (1mm X 1mm x 5mm) and glued these (using Loctite 'All Plastics' superglue) almost vertically onto the baseplate sides where the brakes were to be located, overhanging the bottom edge by about 2mm. These are to attach the brake mouldings to so they're positioned the correct distance from the chassis and line up with the wheels.
Glueing the brake mouldings onto these strips is quite fiddly as you need to do it with the wheels in place to get them properly lined up. I marked in pencil on the chassis sides where the tops of the brake mouldings should come up to just as a visual reference to try to get them all the same height (some sort of jig might help here). The glue goes off almost immediately the two pieces touch so you have to try and line them up a millimetre or so away and then press down - quite tricky when you're working with tweezers and trying to avoid getting the glue everywhere - especially on the wheels! Again, maybe some sort of jig would come in handy but I'm not sure exactly what.
Once these are all on I can start thinking about painting the chassis and then putting it all back together!
Friday, 15 May 2009
Wednesday, 6 May 2009
Getting it ALL right??
I came across this in the FAQ on Jim McGeown's Connoisseur Models website last night:
It struck me that this is true for all aspects of modelling, not just soldering. Yes, maybe there are modellers out there who manage to achieve a perfect finish first time on every aspect of their work, even the bits no-one ever gets to see, but I'll content myself with bodging my way through and just making sure that the visible bits are tidied up to a decent standard!
Q: How do I achieve the crisp, square and beautiful solder joints with just a mere hint of solder showing that I see on the models built by the experts on the demonstration stands at shows?
Quick Answer: The experts don't achieve much better joints than you, they have just got good at cleaning up afterwards.
It struck me that this is true for all aspects of modelling, not just soldering. Yes, maybe there are modellers out there who manage to achieve a perfect finish first time on every aspect of their work, even the bits no-one ever gets to see, but I'll content myself with bodging my way through and just making sure that the visible bits are tidied up to a decent standard!
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!!
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!!
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