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Fen End Pit

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  1. Fen End Pit

    Christmas engineering work

    By Fen End Pit,


    Stour Valley
    One of my Christmas presents this year was a Sunfounder 10' touch screen designed to fit a Raspberry Pi. How my wife knew I wanted one of these is a mystery, must have been something to do with the hints I dropped. Today I managed to get JMRI installed on it and make up a simple panel to show the fiddleyard of my Stour Valley layout. I intend to also try using it on Fen End Pit. The touch screen works rather well as just touching the point changes it, also if the point get changed by other means (such as using the DCC controller) the change is reflected on the display.
     

     
    The back of the screen has positions to bolt a Pi together with the electronics for the screen and touch inputs. It doesn't come with any cover so I laser cut a piece of acrylic to protect the back.
     

     
    On Boxing Day an enjoyable running session highlighted a couple of minor repairs which were required to track work. So this morning the soldering iron came out to fix a couple of misaligned rail joints. This was a good excuse to drive a few more trains around and take the opportunity to clean a few wheels. It is amazing how much better wagons run when the wheels aren't covered in muck! The J17 turned up on the regular pickup goods easing over the river bridge on its way past the goods yard. Will 2023 be the year I final get around to the buildings in the far corner?
     

     
    Costing past the station building into the platform...
     

     
    ...before coming to a stand next to the signalbox to hand the token to the bobby.
     

     
     
    My wife also managed to buy me a copy of the instruction manual for a Ruston 22RB which will be useful as she also booked an experience day at Rocks by Rail when I will be allowed to try driving one 'under close instruction' which I am much looking forward to!
     
    Season's greetings to you all.
    David
  2. Fen End Pit
    Last Christmas I was given an RT Models sentinel kit and I have to say it was thoroughly enjoyable to put together. Also, given that the kit comes complete with a gearbox and motor, I thought it represented excellent value for money. Readers of this blog will know that there aren't many kits that I build which don't involve remaking at least some parts, either having to get bits etched where the original design is wrong or 3D printing components where features haven't been supplied. With this little Sentinel this was not the case, the kit and the instructions were very good and I had a very enjoyable month or so putting it together.
     

     
    I opted for a green livery, I wasn't confident enough to tackle wasp stripes or similar and I am pleased with the way it came out. The photographs show a gap between the roof and cab which closes up when I tighten a bolt which holds them together! Obviously I have no real prototypical purpose for a Sentinel on my model of Clare but I will probably have a works shunter at my mill siding even though it is too smaller system to justify it in any way - Rule 1 will be applied.
     
     

     

     
    I fitted a Zimo chip and a stay-alive capacitor and it runs rather nicely. I still need to add coal and a crew and apply some weathering but it made a nice change from having to dive into CAD to remodel/redraw things. Having a kit which could be built with all the bits in the box is rare and this was a real pleasure to put together.
     
    Now what hints do I drop to my family for this year?
     
    David
     
     
  3. Fen End Pit
    After over a year away it is time to return to the blog. A lot has happened during the last couple of years which has got in the way but I'm to be back in a position where I can share what I've been building. 
     
    Progress on my scalefour model of Clare has continued slowly. The most noticeable progress being on the area around the level crossing. Thanks to some help from members of this forum I was able to get some plans of the '1865 standard' crossing keeper's cottage. Like all standards they varied a fair bit between the locations and so my model is a representation rather than a slavish attempt to model the cottage at Ashen Road. (In fact my crossing keepers' cottage is on the wrong side of the road).

     
    The gates are now controlled via a small ground frame, an arduino and a pair of stepper motors. I still need to paint the tie-rods and add some rather strange 'targets' which were above the gates and acted as a stop signal for the rail traffic. The picket fencing is a 3d print.
     

     
    Other activities have included continuing with the J17 I was working on. There isn't much of the original PDK kit left apart from the locomotive frames and the footplate. The cab has been redrawn and etched by PPD, the firebox/boiler/smokebox/chimney/dome/splashers/sandboxes/lubricator and tender are all 3D prints. I'm very happy with how it has come out, it still needs some glazing in the cab, some coal in the tender and a load of weathering. This was a steam brake only locomotive and as a freight only engine they were not in the best cosmetic condition by the late 1950's.

     
    One of the more unusual features of this build is that I have represented the internal valve gear with a couple of 3D prints. Modelling up something to represent the valve gear was a fun exercise, obviously this is all cosmetic and almost entirely hidden behind the sandboxes. It is one of those things where you can't see them but you can see the absence of them. I've printed this in two parts which go either side of a frame spacer. The cylinders were slightly inclined upwards towards the front with the valves underneath them. The cams and valve rods are designed to slot over the axles so that the wheels can still be removed if required.
     


     

     
    Some railway companies painted their inside motion bright red, I opted for oily black with a little bit of red visible where the dirty might have been rubbed off when oiling round.
    I've been drawing up the brass components as I've built this and I am considering building a second J17 as the vacuum fitted version. I'm also wondering about a short run kit if there would be interest.
     
    I'll write up some of the other projects from the last year if anyone reads any of this.
     
    David
     
     
     
     
  4. Fen End Pit
    I have been making some more coal wagons for a friend's Irish project. The first attempt were slightly too narrow because some idiot (me) got the dimension wrong on the 3D model. Having fixed that we now have a models of 3 different types of wagon and the beginnings of a coal train. The wagon chassis department is apparently working at peak capacity assembling etched underframes.
     
    The 3 wagons are subtly different, one design has two doors in the middle while the other two have a pair of doors on each side.

     
    I can fit three wagons on the bed of my Anycubic Photon as the wagons are just less than the width of the bed. I have found that printing them at a 20 degree angle, and adding a tiny hole in the floor seems to give the best results.

     
    A close up of the end of the latest batch shows the diagonal layers, but they should be very easy to hide with a touch of paint. I think the tiny 'pressure relief hole' in the floor is helping to avoid layer issues cause by the suction
    effect of the wagon body on the print bed.
     

     
    You can (hopefully) see the differences in the body work when the three models are put together.
     
    Top is the four door variant with one type of door strapping (the top being a T shape on its side).
    Middle is the four door variant with the other form of door strapping (the top of the strapping being an L shape).
    Bottom is the two door variant.
     

     
    I'm looking forward to seeing what they look like with a chassis underneath.
     
    David
     
  5. Fen End Pit

    J20 - now in black

    By Fen End Pit,


    J20 build
    Over the last couple of days I managed to get a coat of primer followed by a coat a Stratford's finest black. This was a heavy freight locomotive and getting towards the end of its life so I've got a fair bit of weathering to apply. On most of the prototype photographs it is almost impossible to see the BR insignia on the tender!  I've noticed I also need to paint the bolt ends on the brake-gear.
     


     
    I'm very pleased with the way the different components came together. The footplate had lots of additional bits required to fill in the space left by the original splashers and the sandboxes were home made 3D printed replacements. Also on the 'still to do' list is the glazing, it looks from the pictures I have that the front side window was glazed but the rear one was not. As I've said before the J20 was a bit of a beast and it makes an interesting comparison with the B12 behind it. Given that the B12 is a 4-6-0 and the J20 an 0-6-0 it is quite amazing that the boilers are almost the same size!
     

     
     

    Next into the works in a J17, this one is a PDK kit but I'm getting a head start because one of my friends built one recently so we know our way around it.
    David
     
     
     
  6. Fen End Pit

    J20 - Some missing bits

    By Fen End Pit,


    J20 build
    Having put the J20 together and painted it I spotted that I'd missed a couple of important bits off. The first were the front guard irons which were easily soldered onto the front of the chassis. The others were, it appears, completely missing from the kit, these were the two large lockers in the cab, one of which has the reverser mounted on it. The kit appears to not have parts for these at all and they are not mentioned in the instructions. Photographs of cab interiors are notoriously hard to come by but the instructions for the 7mm scale Connoisseur kit had a good picture of how they expected their kit to be put together. Based on this, and the drawing from the Great Eastern Railway society collection I modeled up the two lockers in CAD and printed them out on the Photon. This was much easier than trying to fabricate them from brass. I thought the little reverser wheel came out pretty well.
     

     
    Once in place the cab looks much better. I need to pick out the dials and gauges and there is a crew on order from Eileen's.

     
    I've also made a start on the J17. So far the frames have altered to allow High Level hornblocks to be fitted, holes have been drilled for CSB mounts and the original slots for frame spaces have been filled. The frames have been assembled using some very ancient Perseverance frame spaces. I've also assembled the coupling rods from an etch produced by a friend which has lots of bits which will help with this loco and put together a High Level gearbox to make it go.
     

     
    Next step is to use the coupling rods as a jig to fit the hornblocks. Wish me luck.
     
    David
     
  7. Fen End Pit

    J17 - Progress of a PDK kit

    By Fen End Pit,


    J17 Build
    For those who don't know what a J17 is, here is a picture.

     
    They were a James Holden designed locomotive built for the GER between 1900 and 1903, a sort of half-way house between the lighter J15 and heavier J20.
     
    As I hinted the J17 kit from PDK is also quite 'old school' by today's standards. The frames just had simple holes for the bearings, not even a half etched line as a nod that some people might spring or compensate their locomotives.
     
    Progress today has been quite swift, partly because I was working with such nice components and probably partly because I vaguely knew what I was doing with them!  The High Level horn-blocks soldered in place easily, jigged into place by the coupling rods. I then added the spring carrier etches to the rear of the horn-blocks, using the 'space saver' design on the rear axle to give more clearance for the gearbox. Having fitted these I then widened the holes I'd drilled in the frames for the CSB (continuous springy beam) carriers. Following various recommendations these are made from Markits WD handrail knobs. Being parallel these can be fitted through from the outside of the frames and spaced from the frame so that the spring wire is the right distance from the frames to match the horn-block spring carriers. I fed a length of spring steel wire through them while soldering them to fit. The result was that the horn-blocks look to ride at an appropriate height and seem to be at the same level and 'sprung' the same amount - thanks due to the famous CLAG spreadsheet tool.
     

     
    One of the extra bits which had been etched was the springs, these solder to the bottom of the bearings and ride up and down with them. The result is that the wheels can easily be removed from the chassis simply by pulling out the sprung wire 'beam)
     

     
    Now I think I'll spend a few days procrastinating before I attempt to do anything with the wheels.
     
    David
  9. Fen End Pit

    J17 - It's deja vu all over again

    By Fen End Pit,


    J17 Build
    So there I was feeling quite chuffed that I'd managed to get the wheels on the J17 chassis. There is a video which includes it running on youtube.
     
    Then I started work on the footplate, I got the buffer beam and valancing on quite nicely and then turned to the splashers. I felt quite good about the job I'd done until I put the footplate onto the chassis and realised that the kit had exactly the same issues as the previously built J20.
     

     
    Now I don't exactly know what size wheels and flanges the designer had in mind but I think they would have made even the most ardent Hornby Dublo 3-rail fanatic blush. The splashers are roughly 4mm larger in diameter than they should be. This, of course, means the hole in the footplate is much too wide as well.
     

     
    Printing out the GERS drawing and pasting the actual size of the splasher onto the kit really shows the problem.
     

     
    The front splasher/sandbox is equally bad, and probably even more of a pain to fix, I'm hoping that the smokebox sides still fit once the top of the sandbox is lowered to the right height.
     

     
    So I now have to remove the splashers, fill the gaps in the footplate, re-cut the splasher sides to the right size and re-bend the tops  to the new profile.
     
    In summary - Grrrrrrrrrrrrrrrrrr
     
    David
     
  10. Fen End Pit

    J17 - Cutting problems down to size

    By Fen End Pit,


    J17 Build
    As I mentioned in my previous blog posting, the splashers on the J17 kit were designed to accommodate the most steam-rollerish of flanges, being almost 4mm in diameter larger than scale. Well I've managed to take them back off the foot-plate. file them down to size and refit them. They look to be about .5mm too large now but I'm ok with a little extra clearance for the springing.
     

     
    Missing from the kit, but visible on the plans and photographs were the beading around the base of the splashers (which is also around the sandboxes when we get to them). This appears to be an L section and was added as two pieces of thin slim brass.  It was fiddly but worth adding I think. It also had the advantage of helping to hide the gap where the new splasher is narrower than the original hole in the footplate. You'll notice that I've also solder the cosmetic piece of the mainframe which extends above the footplate between the splashers. This was obviously now too short to fill the gap. I've cut it as the gap will be hidden by the sandbox.
     

     
    Boy does my soldering look bad when magnified to this size!
    The belpair firebox will need some more drastic work though as there is now as enormous gap to fill.
     

     
    That fun is to come in the future. For now I'm just pleased to have moved forwards rather than backwards. the ride height is obviously wrong as there is no weight on the chassis at present.
     

     
    I did consider forgetting the brass splashers altogether and just 3D printing them and the sandboxes (I may still do the sandboxes as I did on the J20) but opted to stick with the brass for strength because of the limited thickness.
     
    David
     
     
  11. Fen End Pit

    Stour Valley Dream - End of the pier show

    By Fen End Pit,


    Stour Valley
    I've been working on the second of the two river bridges on my model of Clare. For most of the building I've been using the laser cutter to make the brick work but the centre pier of the bridge has two different shapes at the ends. The upstream end is rounded and the downstream end is shaped to a point. The curve is impossible to cut flat and then bend and the multiple corners on the pointed end would have a some nasty joints to hide. I thought I'd give it a go on the 3D printer.
     

     
    I've also printed the girders. The polystyrene in the river bed will get covered in sculptamold prior to adding the Woodland scenics water.
     
     


    While playing with the printer I decided to have a go at a locomotive chimney. I think it is fair to say that the result looked better than the lump of white metal supplied in a recent kit.

     
    Lots of fun..
    David
     
  12. Fen End Pit
    Some more progress on the larger of the two bridges at the Haverhill end of the layout, Ironically I'm building a model of the Stour valley but neither river is actually the River Stour. This is actually a mill race rather than the main river.
     

     
    I had to purchase another set of Woodland Scenics deep pour water to finish the job. Excellent service from Hattons, ordered on Sunday night, delivered Tuesday morning. Mind you, the price of the stuff probably implies that is it made from Dragon Tears fermented in golden vats over a fire made from Dollar bills... At the moment the surface is mirror smooth (apart from some ballast which has fallen on to it and I didn't brush off before the photographs. The intention will be to add some ripples from Mod Podge. I embedded some fine green string fibres into the river bed and I think the effect is pretty good.
     

     
     
    The other big job was sorting out the fascia. A piece of thin ply covers up the more functional ply underneath.  It all makes the layout look quite presentable, particularly as I spent sometime tidying up the railway room.
     

     
    Over Christmas I did a 'stock check' of the library and current count of railway books is around 750. I wonder what 'too many railway books' looks like. The complete run of MRJ and Bylines takes up a fair bit of space too.
     
    More static grass now on order....
     
    David
     
     
     
     
  13. Fen End Pit

    16mm - Return of the Lister

    By Fen End Pit,


    16mm photo-plank
    Some time ago my Lister stopped working during an exhibition, it was returned to its stock box in disgrace and, in the absence of any exhibition outings to provide the impetus to repair it, there it had stayed. However a  birthday present of a copy of 'Picking, Packing and Processing of Peat' by Paul Webb published by the Moseley Railway Trust spurred me into action. It contained too many nice photographs and drawings of Lister locomotives  for me to ignore the overdue repair. Dismantling the locomotive showed up the problem quite quickly. The DCC chip is located under the roof and has four wires from the chassis passing up one of the corner supports. When two of the wires detached before I even pulled them it confirmed that the issue was a broken joint in the wiring. This time I attempted to do the job properly, fastening the wires to either side of a 4-pin Molex style socket. This means that the chassis can be removed from the body and the wiring disconnected.

     
     
    The wiring hides in the canvas weather protection but I need to do more to hide them at floor level.
     
    The locomotive is now back in working order, all we need now are some exhibitions.... maybe later this year.

     
    David
  14. Fen End Pit
    Having worked on repairing my Lister thoughts have  turned to building a new locomotive for Fen End Pit. I'd rather taken a fancy to the tiny battery electric locomotives built by the likes of Wingrove and Rogers and I thought that one of these engines might be worth trying to 3D print. A recent video in the 'Lawrie goes Loco'  series on Youtube also rather drove my project along.
     
     
    There are some superb plans available on Flickr from J. Tilston. I purchased a number of his drawings on CD which used to be sold under the 'Industrial Narrow Gauge Illustrated' name back in the early 2000's. I tried to contact the email address a few weeks back to see if any more were ever produced but have got no reply. Does anyone know what happened to them?
     
    The drawings allowed my to produce a, hopefully reasonably accurate, 3D model of the loco broken down into parts which I thought I could print on my resin Phrozen Sonic Mini 4K.
     

    To give you some idea of the diminutive size of this little critter the 'footplate' was designed to fold up reducing the total length of the locomotive to four feet so it could be lowered down a mine shaft. The wheelbase is the same as a gauge, 32mm in my 16mm:1' scale. The wheels match the diameter of O gauge lowmac wheels. The first attempt to print all the bits took just under 3 hours and came out pretty well - the seat failed to print because I had not really got the supports right and some minor changes were made to the model to sort out the fit and clearances.
     

     
    I painted the battery box from this batch of printing as it came out well enough to use. I'll probably make some spares of this part and also the slightly different version with a 'peaked roof'.  The main chassis is printed in a single part and includes recesses into which four 'High Level' etched hornblock guides can be installed. These were fitted after the assembly of the coupling rods and jigged using the 'rod with a taper on each end' jigs for 1/8" axles I use for Scalefour locomotive construction. I'm still undecided as to whether I'm going to need to work out a method of springing the axles or adding a compensation beam on the front axle or whether this will be unnecessary.
     

     
    The O Gauge lowmac wheels obviously don't have crank pins for coupling rods and are also rather skinny so I tried printing some overlays to go on the front of the wheels. These included a 1.75mm hole in the centre for the end of the axle and a hole into which an Alan Gibson crank pin bolt would self-tap. The actual front edge of the wheel overhangs the rail by quite a margin so I'm hoping I can stick the overlay in place, fill the gap between the overlay and the wheel itself and get away with it!
     
    The rods are just held in place by some wire insulation at the moment. 
     

     
    I've 3D printed the coupling rods and bushed the holes in them with some brass tube. I suspect that in the end I might resort to getting these etched though. They are surprisingly strong in resin but I think metal would be a better choice for long term use.
     
     
     

     
    Ultimately the crank pin bolts will be cut short, proper crank pin nuts installed and then the crank pin covers stuck over them. These covers printed rather well given that they are only  about 6mm in diameter, you can see the bolts and the grease nipple quite clearly. Again, for this test I just used a .05mm layer height, I will probably reprint at .03 for the final version.
     

     
    The wheels (or more accurately the overlays) were quartered by eye and the loco seems to roll along quite happily without binding. The plan for motorizing is to try an N20 type motor for the first time, I've got a pair of the '100 rpm' versions but I'm waiting on a slow boat from China for some bevel gears. The motor is intended to sit in a cradle built into the chassis and there is a cover which will (hopefully) hide the gears from Fen End Pit's sand and make the unit look more like the actual motor which was installed between the frames. (Picture below was version 1) of the frame print before some minor tweaks were added.
     
     
     
    Work on this project will probably pause now until the bevel gears arrive but I'm happy with the progress so far. I am still working on how to manage the power pick up as this locomotive will be powered from the rails as per the rest of Fen End Pit's locomotives. Fitting a DCC chip and stay-alive won't be an issue was the battery box is a very convenient space for them. I'm tempted to try and work out how to split the axles, I think I need to work out how to make some 1/8" internal diameter plastic 'muffs' to go around the axles. This would allow me to just connect some wires to the horn-guides and add some Brassmaster's shorting etches to the back of the wheels.
     
    For now, here are some pictures of the parts, loosely assembled into the shape of the completed locomotive.
     

     
     
     

     

     
    I will admit that I am really rather looking forward to seeing if I can actually make this run. I'm sure it will involve more work and printing - I can see the parts which don't make it being added the end of the Fen End Pit scrap siding, slowly disappearing under the undergrowth...
     
    David
     

  15. Fen End Pit

    Creating a 16mm scale posed engine driver

    By Fen End Pit,


    3D print projects
    Commercial 16mm scale figures tend to be a bit cartoonish and rather limited in terms of style and pose. My tiny new locomotive requires the driver to tuck his knees in to be able to fit in the tiny foot plate, in a mine he'd probably also be fairly hunched to avoid bang his head. I found myself following the same route as Mike Trice in the 3D Printed Passengers thread.
     
    Makehuman is an impressive bit of free software and is not too difficult to use. It is obviously intended mostly for the creation of 'game assets' for computer gamers and features a full range of figure and clothing options aimed at the 'sexy super hero' market. Still there are some clothing options of a more 'traditional' nature and you can create figures that won't look like extras from a Game of Thrones. There are times when some of the options, particularly those around the female form, feel 'NSFW' (Not suitable for Work) but we will pass over those...
     
    Without too much difficulty I created a fairly average looking man in fairly standard work-wear.
     

     
    Once created the figure is exported in a format which includes the 'rigging' which is the technical name given to the bone structure which can be moved around to pose the figure.
     
    Action now turns to Blender, another free application but this time a tool with so many options and possibilities that it is quite impenetrable at times. I had to watch a lot of Youtube tutorials to make any progress at all and still get horribly lost in the interface much of the time. However after quite a bit of swearing I was able to import an .STL file of the assembly for my narrow gauge locomotive. This would give me a reference to pose the figure around.
     
     

    The man was imported next and then scaled to be ~6' tall. The rigging can be seen in the screenshot as he is standing in the default pose from MakeHuman.
     

    Each of the rigs can be moved to give a suitable pose. It doesn't appear though as if the 'bones' are limited to human movement (knees can bend up for example) but after a bit of work I was able to position him seated, with legs pulled into the foot plate and his right hand on the throttle.

    The models have no solid form so it is perfectly possible to stick his foot through the floor. I found that the resolution of the model in blender was a bit lacking for 16mm scale so I also used the 'subdivide polygons' option in Blender to smooth the surface (basically it creates more triangles over the surface. Once happy with the pose the man was exported from Blender as another STL and loaded into Chitubox for slicing for the 3D printer. At this stage I decided he'd benefit from a hard hat so found one on the thingyverse and positioned it on his head.
     

    I printed him out and the result was pretty good. The only thing I wasn't happy with was the area at the top of his thighs were there was an unrealistic crease. I'm sure I could have fixed this in Blender but sometimes filler is so much less hassle!
    I'm not great at figure painting but I'm quite pleased for a first attempt. He still needs some better skin tone and facial features picking out.
     

     

     
    I will probably have a second go at the posing too, I thought I positioned his left hand to rest on his knee but I was obviously a bit off there. I'm also tempted to edit the model to add a hole though his body which would allow wires for a light on his helmet to pass down and then out through the post of the seat. It could be rather fun to give him and the locomotive separate lights, probably not much use on Fen End Pit but vital if we were to ever go underground.
     
    I hope this gives others encouragement to try modeling their own figures.
     
    David
  16. Fen End Pit
    I know I said I wasn't going to make much more progress until a boat from China delivered some tiny bevel gears but I got a bit bored waiting. I decided to see if I could actually print some. Turns out you can, I'm not sure how hard wearing they will be but it is at least a prove of concept. Given that current issues with the Suez Canal (blocked by container ship which has run aground - probably the weigh of all those tiny bevel gears it was carrying!) it was probably a good idea not to wait.
     
    I put a little bit of video on Youtube
    .
     
    I've started the printing for another, a couple of slight modifications to the chassis only.
     
    I've put a Lenz DCC chip and Power-1 in it which actually makes the little motor quite controllable.
     
    I'm now going to work on a different design of battery box (some were fitted with a peaked roof rather than flat top) and also the headlight which was sometimes fitted on a stalk .
     
    David
     
  17. Fen End Pit
    I modeled up the alternative battery box which had the peaked roof rather than just a flat top. I also completed the second chassis, which had a couple of little modifications over the first version. This time I added the spring tags onto the High Level hornblocks and added supports for a length of sprung steel wire. The result is that the axles are now properly  sprung. As the sprung wire connects electrically to the hornblocks and the wheels I used it to feed power up to the motor. I've also managed to finish the coupling rods on this one, fixing the crank pins in place and covering them with the 3d printed covers.
     
    This locomotive has a wheelbase of only 32mm and an overall length of 90mm. I plan to use some thin solder to make the wires from the connector into  battery box and the control console.


     
     
     
    I'll reprint the chassis for the first loco and complete the pair.
     
    David
  18. Fen End Pit

    Level crossing - now in situ.

    By Fen End Pit,


    Stour Valley
    I've been working on and off on making a level crossing for some years now. I've bounced between the electronic and purely mechanical option but finally come back to the electronics using an Ardiuno to drive a pair of stepper motors with simple micro-switches to detect the limit of travel. There is a 3D printed unit under each gate which can actually drive the gate nearly 100 degrees, this allows some over-travel in each direction to take account of the back-lash on the gates caused by there being a little bit of movement in the joiners which couple of top of the stepper motor with the bottom of the gate.
     
    I've obviously got a lot more bedding in to do and also some additional bits like the red targets on the gates and some small wicket gates. But for now it is working reliably and that is a good step forward.

     
    I've put a short video on Youtube to show it moving.
     
  19. Fen End Pit
    I'd spent a fair amount of time trying to solder up a belpaire firebox and despite many attempts I really wasn't that happy with the results. So, as much as an intellectual exercise as with any practical expectation of success, I thought I'd try and model the firebox, boiler and smokebox up in CAD and try to print it. This is very much a 'work in progress' but the results are rather encouraging. The layer lines at a .03mm layer height are virtually invisible to my eye and will disappear even further under a coat of paint.
     

     
    I was astonished by how well the rivets around the smokebox came out and how cleanly the holes for handrail knobs have been printed. I printed the chimney and dome as separate pieces (and haven't cleaned the bottom of the dome off properly hence the poor fit). In terms of the actual model I think the smokebox door needs a slightly more pronounces curve to is and I believe I can probably add the sandboxes to the 3D print.  I might just add the dome and chimney to the model rather than have them as separate pieces. I think a lot of the other issues are related to getting the printing support right, I'm wondering about modeling a support base in CAD rather than adding on in Chitubox.
     
    I was pleased enough with the results to dismantle the etched splashers on the my current footplate so I could match the 3D printed part with the etch - I think the footplate and cab are still best made from brass. Bear in mind that the holes left in the foot plate from the original splashers are over-size and I'll need to fill them to make them the same size as the 3D printed parts. When press down the gap between the 3D printed part and the footplate around the front splashers disappears.
     

     
    So I'm very much encouraged to keep going this route. I will solder up the cab and print the rest of the super-structure with a few tweaks and then see how it all looks.  This was printed on a Phrozen Mini 4K at .03 layer height using 'The Technology Outlets' premier Low odour grey resin.
     

     
    Having read the latest MRJ I would like to refute the idea that this 'Dreadful 3D printing' kills craftsmanship.. It just takes a different sort of craftsmanship, just in the same way that photo-etching brass didn't kill craftsmanship when it meant we no longer had to cut everything else out by hand with a piecing saw.
     
    Please let me know what you think.
     
    David
     
     
  20. Fen End Pit
    I've been doing a number of projects over the last month. More on the etches for the 4mm J17 and also playing with the electronics for my level crossing.
     
    Meanwhile as a more practical modeling activity I've made a start on the shed which is my 16mm photo plank project. The sides of the shed were laser cut in 6mm and 3mm ply. I've deliberately made the back wall in two parts to give me some reasonable thickness for the wall. I have just sanded the outside and have the option to produce an outer shell in the event that I want to include the shed as part of a layout in future.
     
    The insides of the walls were covered in Sculptamold, a layer about 3mm thick. I've been really impressed by how Sculptamold sticks to the ply surface. After about 10 minutes of going off I rolled the surface texture with my 3D printed rolling tool. This came from the Thingiverse. I modified the original 'crazy pavement' version, doubling the diameter. This means that the stones became longer and more suitable for a stone wall. I also modified the shapes slightly adding a couple of extra lines  with model filler.
     

     
    I turned the tool over so the pattern repeat isn't too visible, I also added some additional lines with a scribing tool while the Scupltamold was still green. Finally I used a stiff old toothbrush to add just a little more texture to the stone surface.
     

     
    The effect I'm after is going to be a weathered whitewash inside for the building like this at Threlkeld.
     

     
    The shed includes a inspection pit (which isn't full depth and will probably be covered with timber) and a wagon turn table which would allow a wagon (or loco) to be turned and moved off the running line.

     
    I had cut some ply to form the inset for the track but having seen how well the Sculptamold worked on the walls I think I may just use it on the floor. I'm thinking I want to go for a 'rustic concrete' effect - something that looks patched up and laid at different times. I'm thinking that maybe there were original pads installed for the heavy tools (power hammer, lathe etc) and then the rest of the floor was concreted later.
     
    The door lintels just had some scrap ply inserted when I added the Sculptamold, I intend to add proper lintels either of timber or maybe a modern replacement RSJ. The window lintels are just carved stone (I think I need to make these more pronounced). The windows are only a scale 5' wide which I think is narrow enough to cope with just a stone lintel.
     
    It has made a nice diversion from CAD and MERG electronics.
     
    David
  21. Fen End Pit

    Shiney Shiney etchy things

    By Fen End Pit,


    Ivatt 2MT
    Over the last month PPD have been kept busy with a couple of projects. I've been helping my friends at Brassmasters with a potential EasiChas project.
     
    As I mentioned a couple of months back the cab windows provided for the J17 in the PDK kit I'm building didn't seem to match the GERS drawing very well. I received the replacement etches from PPD and will see how they go together over the next week or so.
     

     
    The second project has been considerably more complex.
     
    Following on from the Easichas for the Hornby J15 i thought I'd try to apply the same principles to the Bachmann Ivatt 2MT. This is very much a work in progress and at this point I'm still at the 'can I get these bits to fit together well enough for me to keep going with the build and find the next set of problems with the etch?' stage.  So far I have made the Easichas overlay fit and got the basic drive assembled. This utilizes the original chassis block, motor and gear tower.  I've spotted several mistakes, mostly in the form of 'that hole needs moving by .5mm'  but nothing too catastrophic. I over compensated for the lack of clearance between coupling and connecting rod so the cylinders, which are currently too far apart, can be moved back to a more scale spacing. I was quite pleased with the way the cross head folded up and soldered together. Using a similar principle to the brakes on my J15 these etchings can be tinned, concertinaed together and soldered up before removing from  outer frame.  There are some minor tweaks to make but not bad for a first attempt.
     

     
    The replacement tender chassis etch also folded up easily.  Obviously I still have to assemble the valve gear, brakes, cylinders etc but it is coming along.
     

     
    Wish me luck as I make my second attempt of Walschaerts valve gear. This time I have will not have the advantage of etches from Dave Bradwell or his helpful advise on the Scalefour Forum. If this doesn't fit together I have only myself to blame!
     
    David
  22. Fen End Pit
    I had the opportunity over the last few weeks to model up a batch of Cavan and Leitrim four wheel vans. These started out as rather odd wagons, with an external wooden frame and a central section of roof left open to be covered with a tarpaulin. Apparently they  doubled up as both general goods vans and cattle wagons depending on weather it was cattle market day! As with all things C&L they were rebuilt over the years and the appearance in later years depended very strongly on who was in the workshop during the rebuild - it seems no two are the same.
     
    I've printed these at .03mm layer resolution on my Phrozen Sonic Mini 4K, print time was about 5 hours for the 3 wagons, I could have got 4 on the plate bed if I hadn't added another little project. I think this is called getting the maximum out of one print run. I've not done any clean up on these other than to remove the support structure, the bottom etches will need a bit of tidying up with a file.
     
    For reference these wagons as in 4mm scale for 3' narrow gauge and each wagon is ~ 62mm x 30mm x 32mm
     

     
    First up with have a van with full external framing, full length centre doors and sun roof.
     


     
    Next we have one with a drop down section and diagonal bracing on the centre doors.
     
     

     


     
    Finally we have a later rebuild with a lowered complete roof, planked centre doors and the original ventilation planks replaced.
     
     

     


     
    These will be delivered to the chassis workshop soon to be married with some etched chassis. This has been a fun little project and I look forward to seeing what the C&L (North Essex division) makes of them.
     
    At the same time I also drew up the back-head detail for my J17, this came out pretty well only I didn't allow enough space for the rear wheels (doh!). I think I'll probably add a few more pipe runs but I'm struggling to find any pictures of J17 back-heads.
     

     
    I'm very impressed with the Phrozen Aqua-Grey 4K resin, it does appear to print very nicely.
     
    David
     
     
     
     
     
     
     
     
     
     
     
  23. Fen End Pit
    Over the past month I decided to try and resurrect an ancient locomotive from my collection. It's not that we've discovered a source of high pressure Geo-thermal steam in Clare, it is just that I fancied trying to get the old Impetus Andrew Barclay fireless to work again. I first built this loco about 20 years ago and I can remember my son, who was about 5 at the time, drawing steam locomotives with their cylinders at the wrong end for months afterwards! The loco was built with a split axle design but still suffered from intermittent pickup. I had a little room left in the locomotive so I wondered about fitting a modern DCC decoder and stay-alive capacitor which might be better able to deal with this. I asked for some recommendations on the MERG forum and then opted to order a Zimo MX617f and KungFu stay-alive 27x9x6. I order these from Digitrains online at 13:30 on a Friday, Order acknowledgment was immediate, an email telling me that the goods had been dispatched arrived at 14:30 and the chips arrived in the post at 10:30 the following morning - Kudos to Digitrains and the Royal Mail.
     
    Soldering the stay-alive to the  chip was nerve-racking but achievable (I believe that Digitrains will do it for you if asked) and the decoder inserted into the top of the reservoir (note: not boiler) . The chips were installed within 24 hours of being ordered! The stay-alive is sitting in the cab but is pretty well hidden. The result is incredible. Before the loco would stutter along and needed to be traveling at an over-scale speed in order not to stall. At this speed the motor was rev'ing very fast and generated an unpleasant whiny sound. After fitting the stay-alive I can now make the locomotive crawl along with its wheels going around at 1 r.p.m.
     
    It really does make for a most unusual model (and as such is bound to be released R-T-R before too long!)
     

     

     
    My second little project has been to work on some tests for a potential little side project. I rather fancy building a small single board 'cameo layout' for the fireless to run on. Many years ago I started a layout based on Mistley in Essex. The layout even got as far as a Scaleforum at City university (I said it was a long time ago) but was eventually abandoned because the maltings buildings were just so damn big and would have taken decades to make in plasticard. But now I have access to a laser cutter!
     
    One section of the building looks like this, the actual building being about 8 storeys tall and ten or so bays wide...
     

    My first attempt was to cut a test section using 3mm MDF for the base and 1mm MDF for the buttresses and detail. Each of these sections is 50mm wide x 70mm tall.
     

     
    While the buttresses were fine the detail on the brickwork was way too course.
    For my second attempt I purchased a sheet of oiled manilla card from Tindall's in Ely. (I corrected the closures around the windows etc. on this too)
     

     
    This gave a better look but the tiny pieces of card were extremely fragile to fit. The multiple layers needed were also very time consuming to add.
     
    For a last attempt I tried 3D printing just the decorative brick work. The part between the buttresses was printed as one piece and the part which wraps around the buttress was a separate piece. I also modeled the decorative diagonal brick course which had previously been cut in 1mm MDF and fitted into a slot in the 3mm MDF base. As I was in 3D printing mode I added some windows and grills to the print job.
     

     
    This was so much easier to assemble and could be made even easier if I cut some alignment holes in the base with the laser and added some location pins on the back of the 3D printed parts. I had a go at painting the test piece with two different colours of brick and then adding a mortar coat with some fine surface filler. Finally a wash with Vallejo grey wash.
     

     
    I think a building nearly 50cm x 25 cm could look rather impressive, particularly with a fireless and a couple of grain wagons shunting in front of it.
     
    I remember an enjoyable operating session on Enigma Engineering (what they make is a mystery) a few years back, this might be a case for Mistrey Quay (who knows what ships from there?)
     
    What do you reckon?
     
    David
     
     
     
     
     
     







  24. Fen End Pit

    Another old friend and more Irish diversions

    By Fen End Pit,


    3D print projects
    The welcome return of High Level Kits caused me to order, amongst other things, one of Chris' 'Rustlers'. I've had an 4mm Impetus Ruston 48DS in various states of rebuild for the 35 years I've had it. My attempts to motorise it have been many and varied but I'd always been stuck driving only one axle. The advantage of the Rustler was that it drives both axles using High Level's usual high quality gears. I had to make my own 4-wheel chassis to fit the gearbox in but this wasn't too difficult using one fixed axle and one which rocks in some 2mm hornblocks.
     
    I purchased another Zimo decoder, this time with a slightly smaller keep-alive. The fictitious 'mill siding' I'd planned for Clare might just have a locomotive!
     

     
    I also had a chance to print up another batch of Cavan and Leitrim vans. These were quite fun to model up as each one is a little different from each other. It would appear me as someone with no knowledge of the inner workings of Irish narrow gauge railways that the workshop pretty much made it up as they went along. Wagons got modified as bits dropped off them and the variation seemed to depend on who was in the workshop on the day and what wood they had available.
     
    So we have one with a low profile roof, end ventilators only and planked side doors.
     

     
    But hey, why change both doors when only one is rotten?
     

     
    and this one still has side ventilators.
     

     
    And finally this one needed a whole new roof.
     

     
    Four wagons made pretty effective use of the Phrozen Sonic Mini 4K build platform. There wasn't much spare space.
     

     
    I just hope the chassis department can keep up with all this!
     
    David






  25. Fen End Pit
    I've made a lot of progress with the Ruston over the weekend. I decided to build the locomotive using 'split axles' for the pick-ups.I decide to try something new here and use the delrin gear as the space to keep the two parts of the axle aligned. The gears are about 8mm wide so each end of the axle is pushed into the gear by about 4mm. A little circle punched from a piece of thin paper is enough to keep the ends electrically separate and the whole lot is flooded with loctite so hopefully it won't move. You can also see in this picture the shorting strips on the wheels which are from Brassmasters. I know the wheels are really too 'thin' for 16mm but having fitted all the rest of the stock with O gauge profile wheels, and built the point work on Fen End Pit to the same standards I have to stick with it really.
     

     
    Firstly I tried running the loco up and down just on DC power. I had to take a fibre glass brush to the wheel treads to remove most of the chemical blackening but after doing this it ran up and down. I benefits from some added weight but there is plenty of room for added lead later.
     

     
    Yesterday was spend in the not very photogenic activity of trying to fit the DCC chips, sound chip, stay-alive capacitor and speaker. The cab has a useful space, formed of a large ballast weight and a locker which gives a useful space for the chips. The speaker is set under the bonnet.
     
    The results can be judged in this youtube clip
     

     
    Today I've been adding more etched bits and some more details in plasticard. I also annealed and bent up the tractor seat, which I'm rather pleased with.
     

     

     
    Next up I have a load of work on the cab interior to do.
     
    David
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