Gareth's Workbench: P4 and 2mmFS mostly

Discussion in 'Workbenches, including workshop techniques.' started by garethashenden, 11 May 2018.

  1. I'm Gareth and this is my workbench. Primarily I model the North London c.1903 in P4, but I also have some 2mmFS models: BR Southern Region, American N scale: Boston & Maine, and a few P4 BR wagons. I tend to bounce around between projects and things spend quite a while half built. My previous efforts are best covered in my RMweb workbench thread here: Gareth's Workbench: P4 and 2mmFS projects - Kitbuilding & Scratchbuilding

    For the most part I'll be posting the same things there as here, but I find that different forums give very different feedback, which can be very helpful.
     
  2. My first update is much more Western than will be typical, but it seems like a good place to start.
    Well, I bought a Hymek. I'm a bit surprised by this, but it seemed like a good idea at the time. It's blue and pre-TOPS, so that fits the few BR wagons I've accumulated. It came pre-weathered from eBay and the person who did the weathering did a very good job. I bought a PenBits sprung bogie kit for it and over the past week I've been putting it together. It went together very well and now that it's almost done it was definitely worth it. It runs much more smoothly than the Class 25 I have. I still need to add the brake shoes, and weather the wheels and buffer beam details, but it's almost done. I think the Class 25 will get sprung bogies too at some point.

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  3. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Join the club :thumbs:. I'm quite adept at starting things and end up with about half a dozen projects in various stages of building.
     
  4. adrian

    adrian Flying Squad

    That's a nice eclectic mix, I'd be interested in any/all of the above. re. the half built projects as they say the enjoyment is in the journey and not the destination.
     
  5. I've dug out both my lathe and my 2mm M7 and I'm having a go at boiler fittings. I've made three chimneys, number two is the best but it still looks weird. I'll need to make at least one more. The first dome, however, came out really well. It needs to be soldered in place and then have the bottom edge formed, but one step at a time.

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  6. I've been working on a few American N Scale projects the past few weeks.
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  7. And now for something Great Western. I’ve been tasked with building a broad gauge GWR Buffalo 0-6-0 saddle tank for a friend’s EM gauge Cameo layout. Above the footplate the two are pretty similar, but the footplate itself is a rather curvy affair with minimal clearances over the wheels. Prototype Buffalos had double frames, on the NG engines the wheels were in between the two frames, but on the BG engines the wheels are outside of both sets of frames. I started with the inner frames, fitting them with High Level hornblocks and CSB suspension. I used the P4 spacers to give the maximum space between the frames. I’m going to fit a Finney/Brassmasters Dean Goods inside motion kit once it arrives.

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    The curvy valences are an important feature of the engine and seemed like a good starting point for the body work. In the end I ended up making two sets as the first set didn’t come out too well. I haven’t been able to find a drawing of a BG Buffalo, so I used a good side on photograph as a guide. I sweated two pieces of 0.010” nickel silver together and glued a scaled copy of the photo on top. I’m not sure if it was my cutting or distortion in the photo, but this set of frames came out with a distinct bow. For the second set I did it properly, marking everything out on another pair of nickel silver sheets. I cut out the rough shape with a piercing saw, and then spent several days finishing the shape with a collection of files. Eventually I was happy with the look and shape of the valances, now on to the footplate.
    I started with a sheet of 0.008” nickel silver. I cut this to a width of 34mm but left it the full length because I didn’t know how much material the curves would use up. I used the valances as a guide while forming the wheel splashers. The first one went fine, but something went wrong with the second one. I cut them off from the strip I was working with and tried again. The second attempt was better, but still not good enough. It was about this time that I remembered that brass is far easier to form than nickel silver, so attempt number three was made from 10 thou brass. This went much better. In fact it went so well that there was no need for a fourth attempt. The next tricky part was going to be attaching the valances to the footplate. The curves in the footplate gave it a springy quality that made final positioning a bit “adjustable”, this was both good and bad. To solve this, I found a rather sturdy bit of brass bar and soldered it to the underside on the footplate. I started at the front, checked the position of the first arch, soldered that to the bar, moved on to the second arch and so on. This worked well and I was able to attached both valances without much trouble. I was also able to remove the bar without losing the valances, so all good.
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    The next step will be to file the footplate to length, it’s currently overhanging at both the front and the rear. After that I think it will be time to cut a hole in the middle. I’ll need to work out soon whether I want to attach the outside frames to the footplate or to the inside frames. The footplate would be easier, but the brakes attach to them, so it should probably be the the frames.
     
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  8. Well that didn't go to plan. It didn't occur to me that behind the splashes needs to be a section of flat metal. Amount other things, the springs need to attach to this. Doing this from the footplate I had, would mean that I'd have to let in short sections behind the splashers. Another problematic area was the cab floor. My two options were either to flatten out the curve between the arches, or to cut it out and let in a new flat piece. These problems, coupled with a couple of dents/ripples in the footplate lead me to deciding that the best option would be to start over.

    A fresh sheet of 0.010" brass was obtained and marked out. I marked out both the splashers and the space between the frames and went to town with the piercing saw. About two thirds of the way through cleaning up with a file I realised I'd messed up let again. I had cut out too much of the cab floor. But after thinking about it a bit I realised that it didn't actually matter, because the cab floor is slightly raised relative to the footplate, so I can fix the problem by adding a new layer on top.

    The valances were salvaged from footplate number three and put onto footplate number four. Because of the differences between the way I made the two footplates, the valances needed to be modified very slightly. A few corners were squared up, and everything fit quite well. These were attached to the footplate followed by the splasher sides from the original kit. That's the progress to date, next up is to make and fit the splasher tops. The ones in the kit are too narrow, and one pair has a cutout for something, possibly the smokebox.

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    AJC, Rob Pulham, Ian Smith and 3 others like this.
  9. An Update!
    The inside motion has mostly been assembled. It has been and interesting process. I've been following the instructions, but things have been slightly complicated by trying to fit this into an engine for which it wasn't designed to go in. The first problem I encountered was in fitting the cylinder block/motion bracket. The hornblocks were in the way of the slidebars. These were High Level Standard hornblocks, I replaced them with a pair of Spacesavers. This seemed to work, although I have just discovered it didn't, more on that later. The next problem was the CSB wire. This just couldn't get through without major cutting to the motion brackets. So that was set aside for a while. I decided that the best option would be to compensate the front axle, rather than spring it. Martin Finney's kits are all designed for compensation and the cylinder block end includes a mounting point for a compensation rod.

    On to the crank axle. The casting for the cranks were cleaned up and the axle holes enlarged slightly to fix the axle. The other bits, eccentrics and eccentric sheaths, were fitted and tired in place. It fitted, so I disassembled it, carefully added silver solder, and put it back together. I took it outside and used a torch to melt the solder. I suspect the 3C weather didn't help, but it worked well none the less. I cleaned it up, thought it could use a bit more solder, added some, and resoldered it. The axle then was cut and cleaned up.

    I fitted the axle to the chassis, and I tried it with the connecting rods and crossheads. I immediately ran into problems, quite literally. The sides of the connecting rods, where they attach to the crossheads, hit the hornblock sides. The next problem was that ends of the eccentrics hit the motion bracket, the bracket was too close to the axle. So the motion bracket assembly has to move. This brings the story up to date. I find myself needing. To make some fairly substantial modifications to the chassis, moving the bracket and doing something about the hornblocks. I've managed to find some Comet? hornblocks that fit 6mm openings in the frames, rather than in separate etched hornguides. This gives them an advantage in this situation, they are far narrower than the alternatives. While I'm changing the front pair, it makes sense to change the rest as well and fit compensation to the back two axles at the same time. Having a compensation and springing hybrid system seemed like a bad idea, so the springing will go. In the morning.

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    Peter Cross likes this.