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2mmMark

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  1. 2mmMark
    The previous instalment finished with the motor about to undergo some surgery to shorten the shaft. Motor shafts are almost always hardened steel so regular wire cutters will make very little impression on them but the shaft will certainly leave an impression on the cutters. The best way to trim the shaft is with a cutting disc in a minidrill. This is a little risky so sensible safety precautions are strongly recommended.  Eye protection just in case the disc breaks up is required and definitely think about a safe way to hold the motor during the process.  In this case, the photo below shows how I did it, by holding the other end of the shaft in a pin chuck, which has the benefit of allowing the cut end of the shaft to be give a slight bevel to tidy up the cut. The cut end is simply rotated while gently touching the cutting disk at an angle. Fingers are safely out of the way of the disc.

    Note that the disc isn't spnning when I took the picture. Even I'm not mad enough to try that!  In this case, I'm using a carborundum disc as I beleive they give a neater cut. Diamond discs are an alternative but they seem to "bounce" a little bit and in my hands at least, don't cut so nicely. In the previous instalment, I mentioned a flywheel,  which I turned up on the lathe. It's just a piece of brass rod, nothing fancy. Alternatively, nicely made flywheels are available off the shelf from Tramfabriek or N-Brass.

    The other end of the motor had the work affixed. For this I used Granville thread-locking fluid from Halfords, as recommended to me by Sven van der Hart of Tramfabriek.  The bond is good but can be broken if required for dismantling. Some of the Loctite compounds I've used in the past are quite permanent.

    At this point, the power unit comprising motor, bracket, worm and flywheel is ready to use. The next thing is to arrange an electrical connection between the frames and the motor contact tags.  A very simple solution was to trap some springy phosphor-bronze wires between the frames and spacer. As the spacer is plastic, all that was needed was to cut a groove in which the wires are trapped by the frames. Underneath the spacer, in the axle aperture, the wires are just bent over to trap them in place. The following set of photos should make things clear.





    The feed wires are easy to simply spring apart if it's necessary to remove the motor.  In this case, the motor was in the right orientation to give forward movement with the right hand rail positive.  If it wasn't correct, all that's needed would be to rotate the motor 180 degrees.

    The body has had some attention. It's gained a set of large headed industrial buffers and foot steps. The buffers are regular loco buffers with an extra etched head soldered on. Looking at photos of various industrial locos, the real thing also extended buffers in this way. Probably not with 60/40 tin-lead solder though. The footsteps are lost wax brass castings from the N-Brass range.


    Putting the steps and buffers on required a bit of shaping to be done to the PCB underplate (mentioned in the earlier "Bodywork" section). Some 14BA nuts were soldered to the copper side to accept the fixing screws of the chassis


    A couple of brass pins were fitted into the space to provide some alignment for the chassis. In this view they can be seen just ahead of the worm & gear.
    In due course the PCB plate will be glued in place rather than soldered to avoid any risk of the copper delaminating.  A glue joint here will be amply strong enough.  As mentioned previously the edge of the PCB represents the footplate valance.

    Some satisfying progress made, I feel. What has become apparent now is the emptiness of the cab. It looks like some representation of the backhead and a brake standard will be required.

    I've also found some photos online of a similar loco to mine, not identical but they certainly give some idea of how it could be finished.

    From Flickr, this image was taken in 1967 by John Wiltshire at the Millom Ironworks in Cumbria. An inspirational image. It gives a good idea of what additional detail remains to be added.
    Also on Flickr from Gordon Edgar are these images of the same loco, showing some detail differences.

     

     
    Mark
     
     
     
     
  2. 2mmMark
    A little white ago, we left the chassis soap opera with this cliff-hanger "Coming in part 3, mounting the motor and meshing the worm & wormwheel". Well, it's here at last!.
     
    The chassis block and frames have been trimmed up thus


    This chassis is a particularly unfancy set of ironmongery, referring back to the prototype photograph in part 1
    http://www.rmweb.co.uk/community/index.php?/blog/1345/entry-14132-peckett-y-class-framed-part-1/
    Note the lack of anything resembling guard irons. They've either been knocked off or deleted by a cost-conscious accountant. I suspect the latter. Anyway, it's jolly convenient for a lazy person like myself. The ends of the chassis have been given a recess where the buffer beam will sit, in order to avoid a short circuit across the split frames.
     
    Next on the agenda is how to power the locomotive. I chose to use the flat sided can motor available from the 2mm Scale Association. This is a compact powerful and smooth-running unit. It has a pair of mounting holes in one end which accept an M1.0 thread (12BA can also be used). Here's the motor and worm. The worm & wormwheel are Association products from several years ago but are none the worse for that.

     
    I needed to use the motor in an upright configuration which meant there was not a flat surface allowing the motor to be glued in position. To be perfectly honest, I'm not a fan of glueing motors in place. It's a perfectly sound practice and with the right adhesive, will give no problems. It's just that I prefer a slightly more engineered solution. What was needed was a strong right-angled section to mate up with the chassis block and hold the motor rigidly in place. I chose to use a section of 12mm aluminium angle of the type available from DIY stores. This has the hard work done as a slice of it will give an accurate 90 degree angle. It was drilled and shaped using my Proxxon MF70 mill and finished off with files. A mill isn't necessary, it's just a quick way of achieving the end result. Hopefully the photos will show the small amount of shaping and drilling needed. The base was tapped 12BA for the mounting screw.

    The large countersink is to accomodate the bearing boss of the motor, so it sits flush against the mount.

     
    With the motor attached, it should now be clear it's held in place. The front face of the mount has a small recess to allow the mount to be as close to the wormwheel as possible.

     
    To fine-tune the mesh of the worm and wormwheel, the base is carefully sanded on some wet & dry paper glued to MDF. Working slowly using a circular motion, it's possible to reduce the dimension quite precisely.

     
    The fixing screw is placed in the chassis

    then the mounting is screwed in place. It is just a fraction narrower than the central chassis block thus electically isolated from the frames.

    A single mounting screw has proved quite sufficient to hold the mount in place as there's quite a bit of friction between the mounting and the chassis block. If it becomes necessary, a small shear-pin can be inserted to lock everything in position.
     
    The worm is slipped onto the motor shaft and as can be seen, the meshing is just about right. There are a number of ways to get the worm/wormwheel mesh correct. For every combination, there is a specific dimension of axle centres but as these are at right angles, I personally don't find it easy to use. Originally, I started off using either a "Rizla" cigarette paper or a sliver of aluminium kitchen foil to set the meshing clearance. Nowadays, I tend to eyeball it and work by feel, knowing from experience how much backlash there needs to be on the wormwheel. The photo below shows the result

     
    Using a steel worm on the motor shaft, there is a way to check the mesh is a happy one. The worm is reamed out so it easily rotates on the motor shaft but has no perceptible clearance. This allows the worm to be spun on the shaft by fingertip to ensure there are no tight spots and it all rotates freely. A fingertip is a surprisingly sensitive measuring device! Once everything is confirmed OK, the worm will be secured with a drop of Loctite.

     
    Now we can try the chassis against the body. The unused end of the motor shaft needs some trimming to fit. This is marked with a felt tip permanent marker and will be cut off using a carborundum disc in a mini-drill as the motor shaft is hardened steel. The shaft won't be completely cut back as I want to try mounting a small flywheel, simply to see what effect it might have.

     
    This brings the progress on this loco up to date. The next instalment will hopefully cover the fitting of the coupling rods, flywheel and wires to the motor.
     
    Oh yes, I fibbed about the "small recess allowing room for the wormwheel". I made a mistake with the position of the mounting hole and had to relieve some of the mounting to allow the wormwheel to rotate because I did not particularly want to make another mounting...!
  3. 2mmMark
    Well, it's certainly been sometime since I last updated this blog! In the intervening time, it seems that Pecketts have become very fashionable. The Hornby version is indeed a superb model and has deservedly been a runaway success.
     
    This has prompted me to get a move on with my model, which has been languishing for a while. In an effort to get motivated, I've put some boiler fittings on, to make it look more like a loco.
     
    The fittings have all come from the N-Brass range and are lost-wax brass castings, which makes them easy to solder in place. The castings used are:
    - Chimney - Stanier 8F, part no. 2042
    - Dome - LNWR Coal Tank Safety Valve, part no. 2027
    - Tank filler - LNER Pacific Tender Filler, part no. 2098
    - Smokebox door - GCR ROD Smokebox Door, part no. 2113.
    Bit of a mix and match but they fit the bill.
     
    The etched saddle tank comes with holes to locate the fittings. These needed just a little easing out to ensure the chimney & dome were centralised.
    The tank filler needed slightly different treatment as the casting is quite tall and it needed to be recessed into the tank. Comparison of the two photos below shoe the adjustments. The chimney did need to come backwards slightly, hence the oval hole.


    The smokebox door had its casting spigot removed and it was then thinned by rubbing on some wet & dry paper glued to a piece of MDF. The beauty of it being lost wax is that it's much more robust than a white metal equivalent. The door darts remained intact. The secret of doing this kind of work is to work slowly and steadily in a circular motion, and to dampen, not soak, the wet & dry paper.
     
    Here's the result of the initial soldering

     
    Everything is firmly fixed but in need of a bit more solder fillet in places.



    Showing an improvement but still some more work needed. In fact there are a few gaps which will need filling. I'll be using solder for this, sanding, filing and scraping back where necessary. I make small sanding sticks by cutting pieces from emery boards. It's a good way to get into small areas and corners to remove solder. There's no need to worry about clogging a file.
     
    One final task was to grind away the excess of each casting on the inside, to allow room for the motor.

     
    So, the Peckett is now looking a bit more complete. Some more work to do on the cab with strapping and beading to be added. I've also left off finer details like handrails and whistle as these can be a bit vulnerable.

     
    There's been some developments on the chassis which I'll write about in the next instalment.
     
    As an aside, most of the photos for this entry have been taken using my smartphone, an LG G3. It's got a pretty acceptable camera, which is one of the reasons I chose it.
  4. 2mmMark
    I had a chance to run the Aveling & Porter on Jerry Clifford's "Tucking Mill" today. Looks quite at home, I think. There was one embarrassing moment when the pusher van accidentally uncoupled and revealed the secret of its propulsion but on the whole, it ran acceptably well.




     
    Mark
  5. 2mmMark
    I've been adding a few details to the Aveling & Porter mentioned a while back in this blog. I had hoped to get this done and a lick of paint on the loco for the 2mm Scale Association AGM but I simply ran out of time. I did manage to add a boiler backhead and some rods & piping. There's a bit more to do. Brake shoes are quite noticeable on an Aveling and some steps for the crew will be required. Speaking of crew, I found some nice figures in the Farish range which are just right for the loco. Given that it's pretty open, a crew is an absolute must.
    Anyway, here's a few photos of the current state of affairs.

    The crew are glued to a small slab of black 10 thou plasticard so they can be removed for painting. I expect they'll have awful cramp sitting like this with no support, but that's their lookout.

    There's a suggestion of a firebox door, water gauges and also an etched pressure gauge, which is very prominent on the real thing.


    Most of the details are impressionistic, which is quite sufficient in 2mm scale. So I tell myself anyway.
     
    Mark.
  6. 2mmMark
    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.
  7. 2mmMark
    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
  8. 2mmMark
    "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
  9. 2mmMark
    One of the things I'm pretty good at is starting a new project before finishing off others. Not sure why but I do like the planning & construction phase. I like to get a model running and then it can wait ages to enter the paintshop for final finishing. I also have a lot of unmade kits awaiting their turn on the workbench. I've recently done an inventory and have found at least 17 different locos of various types to build. Getting a little bit scary!
     
    One that's been on the to-do list is an N-Brass Peckett saddle tank. Looking through my stock of wheels, gears & motors, I found enough parts to make a start.
     
    With a small loco like this, I prefer to have an erected loco body to provide a clear idea of the space available for the mechanism, so step one was to assemble the main parts of the body and footplate.
     
    I've chosen to build my Peckett as an inside-cylindered K class. Railway Bylines Summer Special No.2 contains a useful article on Pecketts, which gives principal dimensions for most classes. The N-Brass loco is designed to fit on a Bachmann 0-4-0 but is actually pretty close to scale for a K class. Inside cylinders mean that the chassis is a simple no-frills 0-4-0. 7mm diameter wheels won't need a very high gear reduction to get good running.
     
    The etch is a fairly straightforward one to build, as I'd chosen to take up the option that N-Brass offer of a pre-rolled saddle tank. Nick Tilston, proprietor of N-Brass has a former around which the tank can be shaped. This is a big timesaver.
     
    A few hours work has got me to this stage:

     
    When assembling a kit like this, I use a variety of means to make the bends, mostly blocks of tool steel or gauge plate to ensure good right angle bends. I've never tried a "Hold 'n' Fold" but I'm sure it could be useful. I did acquire some new tools though, a pair of Xuron photo etch shears and a pair of Tamiya photo etch scissors. These made cutting & trimming the etched parts very easy. Money well spent I feel.
     
    Addendum - referring back to the Bylines article, I've just realised it's actually a Y class Peckett I'm building. Faulty memory. For those with the books, the phoot I'm using as reference is on page 47.
     
    For soldering, I'm not one for making "thingies" to hold parts in position. I rely more on tweezers and cocktail sticks to hold parts, sometimes resorting to fingers if I can stand the heat. Nickel-Silver is much better in this respect. The heat transfer through brass is very quick. Still, fingers cool down if blown upon...
     
    As I'm going to use a split-frame chassis, I decided to use a piece of single-sided PCB in lieu of the etched side valances. I cut & shaped a piece of 0.8mm PCB to the right profile for the sub-footplate. The 0.8mm thickness is just right for the depth of the valances.

     

     
    The copper face will be against the body and the chassis frames will butt up against the insulated face.

     

     
    And that folks, is pretty much where things stand at present. The next move will be to make a set of frames. The kit does provide some etched frames but these are quite thin. I'll be using 0.5mm phosphor bronze as this provides a strong chassis with ample bearing surfaces for the axles.
     
    Mark
  10. 2mmMark
    I thought it is about time I documented some of my projects, partly to see if anyone else had similar odd interests and partly as an incentive to getting some of them finished, or perhaps just even started! I am a terrible procrastinator & time-waster.
     
    Why the name “Notlob” you may be thinking? Well from 1864 to 1898, Isaac Watt Boulton ran a locomotive conversion and remanufacturing business, taking cast-off early locos and rebuilding them as industrial locomotives, which were then hired out to contractors. As everyone of a certain generation will know, Notlob is a palindrome of Bolton*. I’m aware it’s “Boulton” not “Bolton” but “Nuotlob’s Siding” just seemed silly.

    Anyone who’s curious about the real Boulton’s Siding could do worse than finding a copy of "The Chronicles of Boulton's Siding" by Alfred Rosling Bennett, first published by the Locomotive Publishing Company in 1927, reprinted by David & Charles 1971, ISBN 0-7153-5318-7. The reprint can be readily be found either as a paperback or hardback. Oakwood Press produced a nice little paperback volume of drawings of Boultons Sidings locomotives ISBN 0-85361-397-4 "Volume 6: Boultons Sidings including Contractors Locomotives" by Mike Sharman.

    Mr. Boulton's activities closely resemble my own modelling in 2mm & Nn3, where for ages I’ve been trying all sorts of shortcuts in the construction of models. This usually turns out to be nothing of the sort and it probably would have been quicker to scratchbuild in the first place. But hey-ho, it keeps me entertained. I also have the attention span of a grasshopper and am easily distracted by interesting diversions. This is why I have five different small layouts and am contemplating yet more. I did once give myself a severe telling off and determined to find a theme and stick to it. I did, for a while...and then my all good intentions failed. I've long ceased to worry about it.

    Anyway, that’s enough for now. The next instalment will be a lucky dip into my store cupboard of eccentric projects.
     
    Mark
     
    *I refer m'learned colleagues to Monty Python's Parrot Sketch…
     
     


  11. 2mmMark
    I forget exactly when it was but at a 2mm Expo a few years ago, I was sitting next to Richard Wilson, each of us doing different demos. Richard was working on something that caught my eye. It was a little cast white metal traction engine which looked rather nice. However, cleaning up the wheel spokes was taking rather a long time. I recalled I had the same kit in my gloat box. If I recall correctly, it's a Fleetline Aveling & Porter. Thinking laterally, a good way to avoid the wheel refining chore would be to put it on rails. Once back home after the Expo, I dug out my kit, found some suitably sized wheels (10mm & 7mm disc) and cut out some frames from brass sheet, getting to the stage below.

    Only the main boiler casting was used, sandwiched in some plasticard to insulate it from the split frames. The next question was how to motorise it. The intention was to have a battered RCH wagon behind as a sort of tender, as was done for some Scottish "pugs". This would contain the motor, driving the 10mm wheels via a UJ to a worm & wormwheel.
    Well this was great in theory but after two or three abortive attempts, it became apparent that this was somewhat ambitious. The drive wasn't very smooth and tractive effort from a single brass driver with not much weight over it was limited. So it was put aside and dragged out from time to time while other ideas were considered.
    Then at ExpoNG, a solution presented itself. Nigel Lawton had introduced his MPD18 drive unit for OO9, which had an 18mm wheelbase - perfect for a 9ft wheelbase wagon in 2mm scale. As a plus point, the wheels were fine enough to be used on 9.42mm gauge as they stood, making a small alteration to the back-to-back dimension.

    Above is the basic chassis etch assembled. I did beef up the bearing surfaces by laminating bits of scrap etch as I felt that the axles running in the 10 thou nickel-silver frames might be a touch under-engineered. Next I sorted out a body. I had some 2mm Association RCH wagon kits but I'd put these away carefully in a safe place... They'll turn up one day! Instead I used a 2mm kit for a LMS van, teamed up with a Peco 9ft wheelbase underframe kit. The plastic body & underframe would avoid any shorting out, useful as the clearances are a bit tight.


    This brought me to the stage below with everything fitting into place nicely.

    The MPD18 chassis was completed and with a little bit of fettling, runs quite acceptably well. The rubber drive belt is definitely quieter than a pair of spur gears but there's still some noise from the final worms & wormwheels (which are Tenshodo products).

    I did wire in the suggested 15 ohm resistor but found it to be unneccesary, so it's been bypassed. I made a rear buffer beam for the loco, fitted some couplers and the ensemble has been trundling up & down my test track nicely.

    It's slightly wierd seeing a box van moving independently! Anyway, it's now functional and will hopefully be visiting one or two layouts at 2mm Expofest tomorrow & Sunday.
    In the fullness of time, the van body will be replaced by the originally planned RCH wagon "tender". In the meantime, the loco crew will have to use big wing mirrors when running in reverse!
  12. 2mmMark
    I've come to the conclusion that I am my own "man from Porlock". I'm so easily distracted from whatever path I've embarked upon. I could have been CEO of a major British .... ooh what's that shiny thing over there?
     
    Anyway, back here on Planet Mark, at the 2mm Expo in 2013, I was chatting with Allan Doherty about various things, including 2mm narrow gauge stuff and he gave me a part completed loco body for a Letterkenny & Burtonport Extension Andrew Barclay tank loco (top one on this page):
    http://www.worsleyworks.co.uk/Image-Pages/Image_NG_Irish-Locos-N.htm
     
    A few days after the Expo, on what was probably the hottest day of 2013, I took a look at the loco and decided to desolder and reassemble to tidy it up a bit. I also wanted to cut a hole in the footplate for the Marklin mechanism I intended to use. Unfortunately, while the cab & tanks came apart very easily, the footplate distorted and corroded very badly. Not sure why, I was using a small blowlamp to melt the solder. Perhaps some flux was still active and extra heat caused it to eat into the metal. It was simpler to remake the footplate from 2 layers of nickel-silver, 10 thou and a slightly smaller layer of 20 thou to represent the valance. I made a boiler from some K&S brass tube and a wrapper for the smokebox. What I ended up with was this:

    The footplate was fretted out to be a snug fit over the chassis and this shows the components loosely assembled.

    You might spot that the loco is now a 2-6-0 rather than a 4-6-0. I did try some experiments to see if the chassis could be altered to suit but by the time the necessary changes had been made, it would have been simpler to build one from scratch. So a 2-6-0 it became.
     
    Then the project, as so many of mine do, became dormant for a while as other things took over - like the unfinished Peckett.... !
     
    With the prospect of Narrow Gauge South West looming in a couple of weeks time, the project needed a bit of a jumpstart, so I took a day off work yesterday to complete the major assembly. I'd already remade the boiler, smokebox and smokebox saddle as the originals didn't quite match the drawing I had (Model Railway News May 1962). Fortuitously, I'd found some suitable boiler fittings from sample castings Nick Tilston of N-Brass gave me to review. These were for a Midland Railway 1F tank loco but suited the LBER loco quite well.
     
    Correction - they are actually the boiler fittings and smokebox door Nick offers for the SECR C-class 0-6-0.
     
    The cab, tanks & footplate were soldered together using 180 degree solder, as were the boiler, smokebox door, saddle, chimney, dome & safety valves. Then the boiler unit was soldered to the footplate, tank & cab unit using 145 degree solder. This was the first time I'd used it. Until now, I've always been a bit of a "one-club golfer" where solder is concerned. The low temp solder allowed me to get the two main units joined without disturbing previously soldered items. I can see myself using this stuff a bit more. At least it's a little bit easier on the fingers! What I'd like is a heat insulating soldering glove, about the thickness of a rubber mechanics/surgeons glove. If someone could invent one of those they'd make millions.
     
    Here's few shots of the bits:



     
    The end result is this:

     
    Next job is to pop on a set of couplings ready for it to haul some Tralee & Dingle coaches on An Clár at NGSW. The coaches are also in an unfinished state...
     
    So that's one distraction moved on significantly. I can now see a part-completed Peckett beckoning.
     
     
    Addendum 20/2/15
     
    Here's a photo of the loco on my layout. The camera can be a cruel critic but I think it's useful to see where improvements in your work can be made. The Marklin wheels do show up as rather coarse in this view and the valve gear could do with a lot of refining.

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