So - first off, the chassis was stripped down to allow easy fitting of the current collector PC board, and to have the outer surfaces of the frames painted black.
The collector wires were soldered to the copper tracks of the PC board, then the motor wires inserted from behind. The pictures do a better job of explaining it:
Above: Here's the bottom view. The brass plate immediately in front of the collector PC board is to hold the bogie radius bar in place
Above: The top view. The motor will hide all this when it's re-installed.
While the chassis was bare, I decided to figure out how to build & mount the cylinders & slidebars. This took a bit of headscratching, as all of the ideas I had up till now involved making up nickel-silver slidebars & soldering or gluing them into minute holes in the rear of the cylinders. I have a copy of "Making Model Locomotives in 4mm scale" by Guy Williams, and that's the method he recommends.
In the end, I did what I should have done in the first place, and that was to pillage my stock of TradeMe bits for ideas.
Some of the ways in which commercial manufacturers made slidebars are crude - to say the least, but on an N-gauge chassis I found what I was looking for. The slidebars are cast from nylon rather than plastic, and are in the form of a simple "L" shape with a pin to plug into a hole beside the cylinders. And they were exact scale size for the loco, too. Brilliant!
Rather than tax my patience by trying to make 2 identical cylinders, I decided to cast them. You can see the results below:
On the left is a tentative Westinghouse pump I've made to try & improve on the rather primitive ones I've done previously. The first cylinder casting is in the middle, and the master is on the right. The slidebars are at the back. Sorry about the slightly fuzzy picture, but lighting wasn't good on this one.
Here's a better shot of the resin cast cylinder with the slidebars in position. The castings still have to be properly cleaned up, and look a bit rough as yet.
I soldered a bit of threaded rod through the frame holes where the cylinders are to be mounted, and left it at that for the day.
Posts
6 comments:
More amazing stuff Greg ! Nice to see you found the bits needed on your Tradme bits, ( you've outbid me on a couple of auctions for N loco & chassis :( Glad they went to a good home ).
Sorry for snaffling the bits, but I've found that "N" gauge mechanisms are a good source of small motors with sufficient poke to also work in the small NZR locos. In fact, the motor I'm using on this project also came from a donor "N" chassis.
Compared with US & UK "HO" engines, ours are much smaller and most of the readily available motors from Mashima & Sagami won't fit.
The old TT chassis from the likes of Rokal used huge motors which wouldn't be out of place in "O" gauge.
really good info from you greg. i like the loco you are building. i have just bought some TT stuff and i'm thinking off a layout to go with it.
Graham
Hi Graham.
I've got some good U.K.-based suppliers for TT kits if you need some. Mostly British prototype of course, but some of their fittings have been useful to me. You modelling NZR?
yes that would be good if you could pass on the UK suppliers 2 me. in 2002 i thought off going NZR TT, bought a Da in Ho i've put a zero one chip in it but will have to remake the bogies to 12mm.
at the moment i'm looking at going british as i now have 20 coaches but only one loco at the moment.
Try these for starters. They're the major suppliers of British TT products that I've found so far. There are others, but they don't have anything like the range of English stuff.
Worsley Works:
http://www.worsleyworks.co.uk/3mm/3mm_List_of_Companies.htm.
3MSR:
http://www.3smr.co.uk/.
I have an etch of one of their chassis I intend to use for a future project. Nice work.
Finney & Smith:
http://finneyandsmith.co.uk/finneyandsmith/
Post a Comment