Pugsley

Thanks Phil, I've got that one, there's also a couple of photos in the Cheona air braked wagons Vol 3. I've got just about every photo of them I can find, but sadly no dimensions, of which the barrel length and diameter are the most crucial. For a small fleet of wagons, they've been photographed quite a lot!

Would anyone have access to a copy of the diagram for these wagons, please? I'm trying to find out a little more information about them for a scratchbuilding project. The underframes look like standard TTA chassis, so the dimensions for these isn't a problem, but I'm struggling to find the barrel diameter. Unfortunately, the scanned diagrams available on the 'net do not cover these particular wagons. Having done a bit of digging this afternoon, I think that these wagons used the barrels from TRL51410-51414, diag TT022B, can anybody confirm this please? And now for the really long shot, if anyone has a photo of the top of these wagons, I'd really like to see it! Also, if anyone has a dimensioned drawing of Oleo 1'8" hydraulic buffers that I could look at, that would again be much appreciated. TIA Edit - Just checked one of my references, and the Nitric Acid tankers only went to 51953. The diagram number is TT022H.

Very nice sir B) That looks good enough to me, even if it's not mounted strictly prototypically. In fact, I'll be stealing your methods for when I set the points up for Bisley Jct.

Have you only just worked out that I don't really know what I'm doing.. I'm not sure, is the honest answer! The primary springs will be easily replaceable, as they'll be a force fit onto the mounting studs. I haven't completely decided on the method of mounting the secondary springs, but I expect the system of mounting to be basically similar, the only thing I might do is solder the springs to the lower mount, but with 145deg solder, so they can be removed relatively easily if required. The rest of the bogie will be assembled with regular electrical solder, with a much higher melting point. The trial primary spring compresses by 1.5mm total, which is about the total movement required from these springs. The idea is that in normal conditions, they'll be compressed by 1mm, giving only 0.5mm of upward travel. The trial secondary spring compresses by 2.5mm, so the plan for this is to have the spring half compressed under normal conditions, giving 1.25mm travel in either direction. I guess that there is a risk that the springs may settle if the model is left on its wheels for an extended period of time, but that's only something I'm going to find out by trying, I think

Similar - I wound them round a suitably sized drill bit mounted in the lathe chuck, then set the thing going at 15 rpm, whilst holding the wire in tension with pliers. I've certainly not done any of the stress relieving part.

I hadn't ever thought about making springs from brass or copper either, until I read the article that inspired this whole little adventure (Chris Pendleton's Deltic article in MRJ). I don't know if it's because they're wound under tension that they work, perhaps? I know that if they didn't work, this whole project wouldn't be feasible, conventional steel springs would look too spindly to be convincing. The LH Loveless Deltic suffers from this to a certain extent.

Great stuff Will, that second attempt at the Rosebay Willowherb looks spot on B) I can see what you mean about the cow parsley, but I can't think of a better way of doing it ATM. Keep up the good work B)

Thanks James B) The springs are made by winding the wire around a drill bit of the right diameter (3.3mm in this case) under tension, before flattening the ends and filing so they sit level. I'm looking forward to seeing the built bogies as well, it's getting ever closer and will hopefully only be a couple of weeks now. I just hope that it's going to work after all this!

More impressive stuff B) B) I'm glad that you're modelling mojo is returning, although it can take some time. I went through a phase earlier in the year when I just wasn't into it at all and achieved nothing for months. It's a pain though, as you feel that you should be achieving something on one hand, but can't be bothered with it on the other!

It feels a bit like the old maths question at the minute - there are three steps forward, and two steps back again. The bogie artwork is currently undergoing another tweaking, but I'm hopeful that the mark 3 version will be the final version, as I've just about discovered everything that could be improved upon, I think.. It's mostly little things, like adding a couple of extra positioning holes on the parts that are soldered on to the mounting plate, but the frames have required a complete redesign. In this version, the axlebox guides will be soldered on to the main frame, with a spacer between to pack them to the right distance inside of the frame. As a part of the final redesign, I've been assembling the various parts, to check that everything works as it should. The following photos show the secondary suspension mount, with the original trial spring in place. Since taking these pictures, I've realised that the prototype spring is too powerful - it needed a force of 500g to compress about halfway, which I think means that the 37 would need to weigh 4kg for it to work as intended! I've since cut the prototype spring down to 7 coils, which reduces the spring force greatly (I'm not sure how much by yet, I haven't measured it). I've got some thicker copper wire on order, so will see what that's like, as I think that the brass might still be a bit too springy. This shows the revised spring length for the secondary suspension, alongside the first prototype primary spring, made from copper wire. I'm not sure if this is final length for this one, the revised frame etches need to be constructed first, so I can work out the height of spring required. The remains of the moulded springs on the kit sideframe, will be turned into locating studs for the primary springs. i had originally planned to replace the equalising beam mounts with an etched part that would actually pivot, but have abandoned that plan for now. I will give it a go at a later date, but with a suitable casting, the etched parts don't look as good as what's there at the moment. This funny looking part: Rests on the secondary springs, whilst also locating the bogie on the pivot. There will be some form of screw adjustment incorporated either into the supports that rest on the slide plates (see next pic), or from the secondary springs to the bolster to give the ability to adjust the ride height. The slide plates and the bolster bearing surface can be seen in the picture above. The plan to stack etched washer-like parts isn't quite working - I need more than I've planned for in the etch, so this will be replaced by a turned brass part of the required diameter, once the next version of the main etches are back, as I don't know what length the part needs to be to maintain the correct ride height at present. The final picture shows the mounting plate in place on the bogie, but it is too close, as mentioned above. There's a few more parts to test this week, then hopefully everything that needs it will be amended by mid-week, so the revised file can be sent to the etchers. More soon, with any luck

That's looking really good Will B) B) B) The small details you've been adding really lift the model.

That's looking nice and the brick inset trackwork looks really good. Was this relatively common in the US then?

Good, innit B) B) B) Very impressive Jo, the Autoballasters are looking great, you've observed and recreated the weathering nicely. The 67 is also very good, nice and subtle, and you've already discovered that the Gouache is great for effects that are so subtle you barely notice them. Any chance you'll be taking them to Taunton with you? It'd be great to see them in the flesh. Nice one B) B) B) B) B)

Yes, it is quite exciting doing the 'worky bits' from scratch, but it has been pretty frustrating at times as well! There isn't much room for manoeuvre in the design - I took great care to squeeze the biggest motor I could in there. The gears are Nylon, so I'm not entirely sure if they'll take paint or not. I'll give it a go on the first one, and try the permanent marker (thanks Jon) if not. I can't help but think that I set the bar too high for myself sometimes.

The first of the traction motor units is substantially complete! There's been a bit of trial and error whilst determining what diameter shafts to use for the 1st stage gear. 2mm was too hard to get into the gears square, despite being designed for that diameter shaft. I've used 1.9mm diamter tubing for the first, with the intermediate gears glued onto the shaft with industrial adhesive, which is supposed to withstand pressures of 3,500psi It's glued everything nice and solid - I've tried turning the gears on their shafts and I can't shift them. The final drive gears will be cross drilled and pinned to the axles to make sure they're totally secure. The pictures give a good idea of how the finished assembly is going to look - the wheels are set roughly to the correct back to back measurement (31.30mm). 1 down, 5 to go!

Thanks James. Yes, fully sprung, with each axle powered by its own traction motor.

The first of the traction motor assemblies is approaching completion, just the fitting of the motor gear to go now (I'm not counting the axle assembly as part of the motor unit - I've still got to thread all 12 parts of those!) Side view of the motor assembly: The first one has been close to disaster a couple of times, due to me not really having a clue how best to put them together I've now worked out the best sequence for doing it, which should make the next 5 go together a lot quicker. End view of the motor asembly: I've also discovered another design fault - I've made the bracket fit the motor extremely accurately, however I hadn't taken into account that the shaft bearing of the motor protudes from the casing by about 0.5mm, which meant that the bracket wouldn't fold square. I've now had to drill the hole for the motor shaft out to 4mm, so it sits nicely in the support frame. View of the motor with wheel, giving an idea of what is visible behind the wheel. With the gears painted black, it shouldn't be too bad : It's all a (fairly steep at times) learning curve, I guess

Thanks Peter B) I don't know about Christmas, but I'm hoping to have it complete enough to run on the S7 society demo track at the Bristol O gauge show in January, but I really should be concentrating on the 4mm layout over winter!

Very nice B) B) The 08 and Shark are particularly good. Sadly, I can't make it to Scaleforum to see them in the flesh.

Thanks Matt, I'm glad you're enjoying it and finding it interesting. I must admit there have been times where I wonder why I even started this project, but I keep convincing myself that the end result will be worth it. It had better be! :lol:

The lack of updates has not meant lack of progress, in fact far from it! The revised etches have arrived - on two sheets this time, 0.7 nickel silver for the larger structural parts, 0.5mm brass for the rest. Some of the parts were too tricky to fold in the initial design. There's still something immensely satisfying about send off a computer file, handing over some dosh and getting a shiny sheet of metal parts in return! Work has also been continuing on other aspects of the project, and the last of the parts required to start assembling the bogies should arrive this week. The wheels have now been reprofiled to S7 standards, which proved a little trickier than the theory suggested, but having said that, I did only manage to bu**er up one wheel! It was one wheel more than I was hoping to, but these things happen.... The wheels have also been reamed to 4.74mm, so they will be an interference fit on the 3/16in axles. One thing I discovered today is that Slaters axles are not 3/16 - they're slightly under (4.72 mm) - as I've had to drill out the hornblocks/axleboxes to fit the 3/16in rod that I have - which is spot on at 4.76mm. I've also milled down the central boss of the wheels so it is now only about 0.5mm proud of the tread of the wheel. The hornblocks have been milled down so they are now rectangular, as per the real thing, and the bearings are in place on the traction motor assemblies. I'm hoping that the 2mm tubing that will form the shafts for the intermediate gears will be here in the next couple of days. Hopefully, further updates during the week will show the first bogie taking shape!

It's all looking good John. I wish I could make it to Scaleforum to see it up and running, but I sadly can't make it. Hope it all goes well for you!