NCB

More often than not on my 3mm engines I have to raise the body for one reason or another, and that's with using 3mm Society finescale wheels with fine flanges. The reason is usually, with etched kits is that the prototype has fairly tight clearances, which scaled down become impossible. Also, I tend to use compensation, which needs a bit of space for the wheel to move up and down. This 517 class has a fixed front axle, with compensation on the rear two: However, the front wheel was so tight in the splasher I had to raise the body by about 1mm, and also move the splasher sides outwards. This Dukedog had compensation on both drivers, and would have been too tight even without: I used 16.5mm wheels rather than the correct 17mm. By placing them 0.25mm lower in the chassis that gave me 0.5mm clearance with the body at the correct height; I then raised the body by around 0.75mm further, if I remember right, which gave me a total of 1.25mm extra clearance. That gave me confidence I wouldn't get the wheels shorting on the chassis. Nigel

Just measured some OO Romfords dating from the 1970s. These also have a 4mm crank throw. Romford did make some TT wheels a fair while ago, not sure what. However, the last was much later and specifically commissioned by the 3mm Society and 3SMR (it's on the 3SMR website) to 3mm Society Intermediate standards; it's 16.5mm 18 spoke. Measuring the wheel on the screen I made the throw 3.75mm, but that's approximate. Looking at your pics, reckon the front driver needs to be slightly further back to match the splasher. If the coupling rod bosses foul the flange under the footplate, reckon the only things you can try are filing the flange, raising the body and/or filing the bosses on the coupling rods. Or use smaller wheels held lower in the chassis.

The 3SMR website has some notes on what sort of wheels are required for particular kits. For the 2P it reckons 6'9" 20 spoke with 22" crank throw. So in theory would need 20.25mm wheels, say 20mm. However, taking the overlarge flange into account something smaller should be OK. Bit suspicious about the 22" throw, think this is diameter not radius, if so should be 11". Also says 9'6" wheelbase, ie 28.5mm.

Coming back to my Cambrian coach drawing, I've just measured the height of the top of my shoulder above the seat squab I'm sitting on, and it comes out at 1'10". Subtract the Cambrian squab to window base amount of 1'2.5", and one ends up with the top of the shoulder about 7.5" above the window sill. That seems reasonable to me.

What you could do with the disc is solder a bit of brass or nickel silver rod across the disc, so the bogie can rock back and fore but not side to side.

Chris, the odd Like will do for me! I hate soldering brass; nickel silver is so much easier. I've built a fair few kits, but mostly ones shot down to 3mm from other scales and that often means problems which need working around. Getting into CAD and etching is a massive step forwards, being able to produce something you know should work. Next step upwards is getting into 3D printing. Nigel

So to the steps: The main complication was due to me soldering a rear step to the front. Doh! With solder then where I didn't really want it, it made attaching the front step in that place more of a hassle than it need be. The tab-and-slot method worked fairly well, although I had to reduce the height of the tabs slightly because the footplate top was behind the slot. Next time I'll etch the tabs about half the thickness of the metal, and make the slots just a tad longer to make sure the tab goes in easily. I have the roof to add the ventilator top to, and smokebox door darts to solder up, and that's the end of the soldering. I'm off on holiday next week, back early July, so reckon things will probably have to wait.

Now the handrails:- The handrails are made from 0.4mm nickel silver rod, and the handrail knobs are Markits N scale. The holes in the knobs need opening up just a tad with a 0.4mm drill, a miniature broach, or both. Next job is attaching the steps; after that there's 2 or 3 minor soldering jobs to do to complete the soldering.

Hi Garry, did wonder if it was you! Anyway, got me used to bidding on Ebay. I had intended to look in just before closing, but unfortunately was sorting out other things that morning and didn't get around to it. Cheers Nigel

Had a shot at a three unmade Kitmasters on Ebay recently, 2 brake thirds and a composite. Would have fitted my requirements nicely. Bid up to £20 but let it go at £21, could see it spiralling, and wasn't sure what a reasonable price would be. Also bid on a Royal Scot and 4 coaches, did spiral and went for around £50. But have just picked up a restaurant car for £5. Nigel

I have a Cambrian 6-wheel coach drawing with a side view which includes the seats. The squab measures 1' 2.5" below the window line. Any use? Nigel

Looking at the pic of the 30:1 full size, it looks to me as though the worm thread is a bit fat for the gear. Basically, when the two are meshed, you should be able to get hold of the gear and feel a bit of play. What you could try is find a position where the two are at the minimum distance possible, find another position where they just fail to engage, then choose something in between. Something which only just meshes is probably OK. Nigel

One thing. I did find using High Level gearboxes improved things a lot. Maybe it's the nylon intermediate gears. But it seems they are pretty free running. I found Romford gears varied a bit. I used Romford gearboxes and wondered if the meshing was a bit too close. The late Jim Russell did a lot of testing of gears, from Hornby Dublo locomotives onwards, and reckoned the best running was always with the gears as lightly meshed as you could get away with; before that there was an assumption that you needed tight meshes. Some people used to use grinding paste to run in a gearbox before using it properly; tried it once but didn't notice any improvement, and reckoned that if you needed to use that method then the gearbox was probably too tightly meshed in the first place.

Thanks, Chris. Ordered the books. I'll leave ordering anything from Shapeways until I'm back in mid July. I've put a post on the 3mm Society e-group. Nigel

Useful list that. Also useful info about the M&M 2-4-0's. I was looking at a pic of one very recently and thought it looked like a Cambrian one. I suspect I may also end up scaling things from photos. My Cambrian interests are roughly in the 1904 - 1910 period so it's a question of working out what state the things were in then. I get the impression that the boiler was either a bit bigger or pitched a bit higher. Fragile 4mm items? Try 3mm! It all depends on what sort of level of detail you want to incorporate. I dabbled in 7mm about 20 years ago, liked it for building models, but not for the space it took up. Hence my switch to 3mm. Nigel

I use most of the small Mashima motors, the 9/16 open frame if I can't get a flat can in, otherwise the 10/20, 12/20 and 12/24 flat cans. Some people swear by the 9/16. Personally I prefer the flat cans; I think they run cooler, slower and have better torque. The 10/15 flat can is to be avoided; heats up very easily. However, my locos don't run in a continuous circuit; up and down a couple of yards is the most they get at the moment, although that should be 5 yards soon, so so long as they don't heat up too much I'm happy. The 9/16 is usable in that respect, but it does get warm. I've just run one straight off a controller with nothing attached, and it's fine free running, but if you slow it down a bit by putting a finger against the shaft it rapidly heats up. I've an idea it may not be the right motor if you're running a train around your circuit. OK for shunting. I've a 9/20 which I've never seriously tried but I think it might be better. Nigel Edit: I've heard the "designed to run hot" bit as well. Don't know that I believe it. Being open frame they will dissipate heat fairly easily, but that's a different matter. I've also heard that "flat cans are worse for heat because they don't let the heat out". Don't believe that either. I don't run locos fast, which may help, but the flat cans I've used have been fine. I have a couple of GWR pannier tanks, one from the GEM kit, one from a Brynkits kit but which uses some GEM castings; both use a modified Brynkits chassis. Both use a Mashima 12/24 motor driving a High Level 1:54 gearbox. Best runners I've got; they will crawl along, pull a house down, and never show the slightest sign of stress.

Hi Chris That pricing makes van bodies look much more attractive. Thanks. I'll pass the word around. Do you know of a good reference work for these? I like the look of your LNWR D84 and D103 wagons. Any chance of making those available? I'm close to finishing the artwork for the other LNWR wagon chasses, although I'll shortly be away for a few week so it''ll probably be late July before I finish them. However, I've already taken a look at the 9'9" chasses as in the D84 and D103. Cheers Nigel

Rear lamp brackets now attached. I'm not enthusiastic about soldering up small bits of folding metal and then soldering them to the body, but managed this OK.

Injectors now fitted, on top of the tank, and the connecting piping bent up from 0.6mm nickel silver wire, as previously indicated: Went relatively easily. Getting the bend in the right place where the piping ducks under the boiler cladding was probably the trickiest bit. Please with this; knew it was going to be one of the more challenging bits. The remaining soldering should be straight forward (optimist!), namely finish the lamp brackets, add the handrails, then the footplate steps, also finish the cab roof.

Certainly looks a bargain.

The injector, Mk. 2! This may do it. The vertical bit is still 1.1mm microbore tubing. For the horizontal bit I used 0.8mm microbore tubing as opposed to a 16BA bolt. 0.6mm nickel silver rod for piping can be run through the tube, as seen, which saves having to try to attach the piping after the injector has been finished. The 16ba nuts were replaced with 3mm Society round 14BA nuts used for crankpins; these are no larger, and are a tight fit on the 0.8mm tube which helps getting things right with soldering. After knocking this up it was a matter of minutes to do the one for the other side. Each tank top now needs the pilot hole for the injector enlarged to 1.1mm to take the vertical bit, and the 0.6mm rod bent to the right shape for the piping. With the previous effort I'd cut the 1.1mm microtube short and shoved in a 0.7mm spigot for mounting it, but for this one I don't think I'll bother. Getting there, I hope!

Might be worth your while joining the 3mm Society, especially for the scenic stuff.

Thanks Jonathan. That's useful. I knew WRRC had a drawing of the Aston Large Sharps 4-4-0 because they did a scan for me a few years ago, but at the time couldn't find a reference for any other MML drawings. I assumed they would have most if not all of the other MML drawings, whatever they are; suspect some are the originals of the copies held by the HMRS. I'll have a think about this. The Tanat Valley book has a useful drawing of a rebuilt Seaham. Nigel

So there is! Not really my era. There's a drawing of a 2-4-0 Sharps in Oakwood's Furness Railway Locomotives and Rolling Stock which looks suspiciously like a Cambrian Albion, but again it's in its original form, whereas I'm interested in 1900-1910, well and truly after the Aston rebuilds. W. Hardin Osborn did a number of Cambrian/Furness drawings for the Modeller. However, these seem to be more sketches than engineering drawings and I wouldn't rely on them too much; I looked at the Large Sharps 4-4-0 when I started on my 00 model and certain bits were way out, such as a footplate much too narrow. Think I'll have an ask on the WRRC site. Nigel

Just wondering, when you've sprayed a coach side, do you have any trouble in getting the windows to fit? I was thinking of spray on the insides of the holes reducing the size of the holes.