2mmMark

Here's a panoramic shot of the layout as it was on display at the Kings Cross Steam Extravanganza last weekend. When we first started work on the layout in 198mumblemumble, John Birkett-Smith produced a model of the model and the layout is now very closely matching that original vision. It's only taken 30+ years...!

I've got a couple of pin vices/chucks which avoid this problem by having interchangeable collet inserts of different sizes. This allows the slots to be shorter and close down more effectively on smaller drill sizes. Mark

Very nice indeed. Is that the plain "carriage brown" livery? This tends to be a bit under-represented in model form. Everyone thinks LNER = teak. I've done some 2mm coaches in plain brown but they need toning down & weathering. Mark

Actually, on the W&U, a lot of the track was beside the road, buried only in weeds. Some of it looked reasonably well kept. It's one of my favourite lines, so I've got most, if not all, of the books on it. Quite hard to encapsulate in model form as that area is pretty wide open. Upwell terminus occupied a huge area. Outwell is quite modellable, there's at least one good 4mm model. If you PM me with your postal address, I could send you some of the earlier 2mm Association moulded track bases plus some rail, for you to experiment with. Mark

If you're sticking with N scale wheels, a 2mm finescale turnout would need some adjustment. However, all is not lost, good looking N gauge track is available from http://www.britishfinescale.com I would think a metre of their track plus an A5 turnout kit would be suitable. Has the Tram loco kit been released yet? Mark

I've been experimenting with point bases milled from a single piece of PCB sheet, in this case 1.5mm thickness. Sections between the sleepers are milled out, at a spacing to match Peco 6.5mm gauge flexitrack, as I was curious to see if I could make a matching turnout for narrow gauge use. If anyone wants to emulate this, it's very simple as the gap between the Peco sleepers is 2.5mm. I used a 2.5mm end mill cutting on 4mm centres to half the depth of the board (0.75mm). So it's a case of cut a slot, wind the longitudinal traverse handle 4 times, cut and repeat. (I've got a Proxxon MF70 mini-mill, which is calibrated in millimetres). Then it was simply a question of soldering the rails on. I used Code 60 to match the Peco track. Having the sleepers rigidly fixed as a single unit made handling the work very easy. It didn't need to be taped down to a plan so I could hold the work at whatever angle was convenient for soldering. I copied the geometry of a Marklin Z gauge turnout which is a pretty good 1 in 6 unit. I gapped the point blades by simply sawing through the base and rail with a piercing saw. The tiebar sits under the unit and is connected to the blades by 0.35mm phosphor bronze wire, coming up through a slot milled in the base. I reckon it was about 4 hours work in total, as there was a bit of time figuring out where things should go and all the rails were shaped individually, as my filing jigs only accomodate code 40 rail. With a bit of time invested in filing jigs for the frog & blades and track gauges to accomodate the code 60 rail, it would be much quicker. The PC board is 0.5mm higher than the Peco flexitrack sleeper base, so that will require some packing to match the height. 1mm thick PCB sheet would have been useful but that's going to be hard to find in the resin/paper material these days. Even with the mismatch of board thickness, I think there's some mileage in this. It certainly results in a very strong turnout. I'm pleased with the end result as a wagon rolls through it quite well. In 2mm standard gauge terms, code 40 rail could be used with or without chairplates and plain track using Association sleepers of Easitrac would need a 0.8mm sub-base to match up the height. Incidentally, if anyone's looking for 3mm shank mills for the Proxxon MF70, ebay seller "tony4cats" sells a range of different size & shape mills which are good value. Mark

Nice robust chassis design, food for thought, Ian. How strong is the Milliput for holding threads? My instinct would be to press in a plastic insulating rod and tap that but if Milliput is up to the job, then seems a lot easier. Mark.

Coming together nicely. I like the subdued colours, really important in 2mm.

There, I fixed it for you.

How's the action on the memory wire? I ended up using a 1.5v AA battery on the sole memory wire turnout I've done so far as with higher voltages, the contraction was much quicker than the current-off expansion. Going down to 1.5v equalised the movement speed. I use a normal zinc-carbon battery, a rechargeable delivers too much current which permanently changes the wire...

That's a good point. I've got some small escapement files which I use if the gears need cleaning up. I find the current range of gears don't need much, if any cleaning up. The older range of gears were machined from pinion stock which did leave some burrs. Mark

All the gears used here are old stock from the 2mm Scale Association. I've had them in my bits box for some years. The integral muffs/gears are no longer made but there are equivalents using seperate gears & muffs. Products are only sold to members but we do have members who use the components for other scales, like OO9. http://www.2mm.org.uk/products/

We last left our intrepid adventurer holding a set of parts for a 2mm chassis but with no way of assembling them. So the first task is to find a way to hold the frames & spacers together. In this case, the frames will be screwed to the plastic spacers using 12BA screws. The first step is to mark out and centre-punch the screw locations. The actual position isn't critical so I decided to place the screws behind where the footsteps will be located. In this photo you can just about see the punch marks. They don't need to be huge, just enough to locate a 1mm drill. Then the frames are placed onto the assembly jig, held down by some tube which is tight fit on the 1.5mm rods and the 1mm diameter holes are drilled. While about it, I also put in some extra 1mm holes, the reason for which will become clear soon. Inserting some 1mm rods to check things are square, the frames are used as a pattern to drill the screw holes only in the spacers. The extra 1mm holes are left alone for now. The screw holes are tapped to 12BA. The correct tapping size is 1.02mm but for this plastic, 1mm will suffice. While on the jig, the extra 1mm holes are drilled to a short depth, 2mm or so and left as blind holes. Into those holes are inserted short lengths of 1mm rod, to act as locating pins for the frames in addition to the screws. The 1mm pins are fixed in place by Loctite 639 retaining compound. This photo shows the frame dropped onto the pins. No need to go mad with the pins, I use just enough to keep things in place. The pins are filed off flush with the outer faces of the frames. The screw hole is enlarged to clearance size for 12BA (1.2mm) and also countersunk. For this I simply used a larger drill (4mm) twirled in my fingers. With the pins in place and the screw holes ready, the frames can be assembled. This results in a fairly solid frame block. There's no need to overtighten the fixing screws, in fact doing so risks stripping the thread in the plastic spacers. Finger tight on a jewellers screwdriver is sufficient. Now its time to fit the wheels and gears. Here's the parts for the unpowered front axle: Going from left to right, we have a wheel, M1.6 washer, axle muff, M1.6 washer and a wheel. The washers are used to take up some sideplay, which was a bit excessive. Here's the rear driving axle: From left to right we have a wheel, a integral axle muff and 14 tooth gear, a M1.6 spacing washer and the other wheel. Mounted in the chassis, they look like this: Now let's look at the intermediate gear shaft: Left to right is a 1.5mm stub axle, 28 tooth 100DP worm gear, another integral 14 tooth gear/muff, a M1.6 spacing washer and the other stub axle. Mounted, they look like this: Because everything has been checked and aligned previously in the jig (see part 1 of "Framed"), the gears mesh sweetly and the chassis rolls very nicely. The chassis block is still overlength at present but it will be trimmed back soon. Also, nothing is locked or glued in place yet. This will be done at final assembly stage when the motor mount is ready. At this point, it's good to have a little gloat at having made a free-running chassis with all the wheels square and gears meshed correctly. Coming in part 3, mounting the motor and meshing the worm & wormwheel.

If I turn the motor through 90 degrees, yes it would fit. I notice Parkwood Models have released a new resin casting for the LNER built 350HP shunter precursor to the BR version. That's tempting.

I found a set of photos I took when building an 08 chassis a few years ago. These predate the 2mm Scale Association kit for the 08 shunter and the chassis is now sitting under an original Farish body, with all its inaccuracies. My aim was to see how a triple stage high reduction chassis might turn out. Quite well as it happens. This isn't a complete build sequence but hopefully 2mm people might find the photos informative. The starting point was a set of 9mm loco wheels which had failed QC checks for having inaccurately drilled crankpin holes. As I was going to convert them to outside frames, this was of no issue and the price was right... ;-). The wheels were mounted in my lathe and the centres drilled to make the axles hollow, to accept a set of cranks made from pins and parts of the Association etch of replacement coupling rods. The cranks were set in place by means of a simple spacer Here's an assembled wheelset A set of frames from 0.5mm nickel-silver were set out for axles & gears, cut out and spacers made. The frames were fitted with shear pins to line up on the spacers before being finally screwed into place. There was a touch too much sideplay in the axles, so I soldered some thin shims in place to take this up. They were made from phosphor-bronze pickup strip. One small but key detail is an end-bearing for the motor shaft. This keeps the worm firmly in mesh These photos show the gear train. The middle step-down is very close to the centre axle muff but there's just enough clearance. Once assembled, the chassis block looks a lot tidier Here's a close up of the motor shaft bearing. It also helps locate the motor in position And the other end is fixed by a bracket So there's a few ideas for chassis construction. I'm not sure that the complication of the triple reduction was entirely justified but the loco does have an appropriate top speed. It's a reliable performer and is very controllable. However so is the end result from the 2mm Association kit and that has a reduction around 40:1, albeit with a coreless motor. Mark

Don - the MF70 is a great little mill. The Proxxon cutters are very good but expensive. Plenty of alternative 3mm or 1/8" shank cutters are advertised on eBay. My tip, get really familiar with the orientation of the controls so they are almost second nature.

Don - I was given a few square inches of

"I didn't do nothing wrong, but I always got the blame" sang Alex Harvey in Framed. Well, let's hope nothing goes wrong in making the frames for the Peckett. An inside framed 0-4-0 is a reasonably simple starting point nowadays. When I first started in 2mm finescale circa 1982/83, something like this would have been much more difficult, as appropriately sized wheels & motors were just not available. Today, the 2mm finescale modeller is almost spoilt for choice. Normally, you'd start with a drawing of the loco to get the frame dimensions. In this case, as I already had the body defined by the N-Brass etch, I worked from a photo and some known dimensions like wheelbase, wheel size and length over headstocks. What I did was scan and print the photo from the Railway Bylines article which gave me the ability to measure and scribble on a few key dimensions. Combined with the set size of the body, this gives a reasonably accurate starting point. I then worked out how these translated to 2mm scale and made a few notes as an aide-memoire. I find Post-It notes handy on the workbench as they tend not to go missing at crucial moments. A calculator is also useful when converting between scales. Ignore the 2 places of decimals, it's just what the calculator and digital calipers said. I round up to the nearest "eyeballable" measurement Some people plan out their frames in detail, I tend to "wing it" and pretty much make things on the fly. Sometimes that comes back to bite me but most times it works out OK. I do have a one chassis that has a redundant set of gearshaft holes...! The first place to start is with a pair of coupling rods. This is the critical dimension for frame building. The rods and axle holes must line up. If they don't, you're on a hiding to nothing. Luckily, the 2mm Scale Association does a useful etch of rods. The Peckett has a 7ft 6in wheelbase which defines a 15mm distance between axle centres. On the etch are 14mm x 15.5mm and 14.5mm and 15.5mm rods. I decided to use the 15.5mm section from these and not worry about the scale 3" discrepancy. Shocking inaccuracy, I know! As it stands the etch is 0.010" thick which is on the thin side for motion so I doubled up the rods by cutting the etch tabs, folding them over and soldering one rod on top of another. This gives a set of rods which can now be used to mark out the frames. Full cleaning up can be done later. The frames are cut from 0.020" phosphor-bronze strip. The association sells this a convenient size for 2mm frames. Below shows a piece of strip and the shaped frames. Two pieces are laminated together by temporarily soldering at the ends. Making frames as pair like this makes life a lot easier. The way to proceed is to drill all the required axle and gear holes before shaping the frames. Accuracy here is important so get the holes right before spending any time shaping the frames. If these key dimensions are wrong, you may as well throw the frames away and start again. If you spent time nicely shaping them with guard irons and the like, the pain is greater! Fortunately, the Peckett has a pretty basic frame profile. The photo shows the axle holes and also the hole for the intermediate gear. Gear meshing is made easy using the 2mm Scale Association meshing tool. This has a sliding shaft and two hardened pins on which the gears can be mounted and correctly meshed. Once the mesh is set, the pins are used to mark the position on the frames. Hopefully the photos below will elucidate. Meshing tables are published for all the Association's gear range but using the tool is much easier. This shot shows how you'd overlay the rods on the frames to mark out the axle holes. I didn't photograph this at the time so it does show the shaped frames, contrary to my advice earlier. I did all the drilling using a drilling machine. Apologies for the mention of machine tools! It's perfectly possible to do all this with simple hand tools. Machines make the job quicker and easier but they aren't essential by any means. Here are the components for the chassis. The frame spacers are milled Acetal blocks, 1/4" wide. I got this idea from Denys Brownlee. These will give the necessary insulation for split frames and allow the frames to be easily screwed to the spacers. I prefer frames assembled in this way. I've nothing against soldered construction using PCB spacers, I've got a couple of chassis constructed this way myself but it's nice to feel that a chassis can be more "engineered". The wheels are 7mm dia., the two coarser gears are 14 tooth 64DP and the worm & wormwheel are 28:1 100DP. I needed an intermediate gear to keep the motor level to fit the body and a 28:1 reduction will be sufficient with the small wheels. For this chassis, one thing I've made is a simple jig, for which I got the idea in a recent Model Railway Journal article on 2mm chassis construction. It's simple a piece of melamine faced chipboard with 1.5mm rods inserted where the axles and gear shaft will be going. It'll be useful to keep frames inline when assembling the spacers and it's proving very handy for setting out the gear train and position of the motor. That's where things stand at present. I have a set of parts which should be reasonably easy to assemble. The proof will be in the pudding! Mark

Andy, what are you using as your drawing tool? I've got plans to do some etch design (one of which is a Rock Island outside braced baggage caboose, amongst other oddities). I have a copy of TurboCAD to use but I know people have had success with simple vector graphics packages. I'm also curious about the brake gear on the bolster. Why is it reversed from the usual orientation? Must have made it a bit awkward for the shunters. Mark

It's a very difficult call. Lining in 2mm is tricky, do it to scale and it's almost non-existent. Having been on the operating side of Wadebridge at Railex, all I can say is that it didn't seen jarring to me. Operating Wadebridge was my 1st experience with DCC and I have to say, DCC suits the layout very well. You can make all the operating movements which the prototype requires with minimum of fuss. Will I be changing? Probably not as for my style of layout it would be overkill but it's perfect for John's layout. Still needed to prod the odd loco from time to time. Mark