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TurboSnail

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  1. TurboSnail
    To be honest, I've neglected this project a bit too much. But it's back on the bench now, with handrails, a driver and a couple of other bits added last night. The chassis (version 4? version 5?) is now working nicely too, so looking like we're on the home straight at last.
     
    That paint job is really rather gaudy isn't it? I fancied a change from the nice refined dark blue I normally use, and I think it'll look a lot less toylike once it's been weathered.
     

  2. TurboSnail
    Ah, the joys of 3D printing. The first test of the SER brake van (diag. 1553) looks to have come out ok at first glance - but a closer inspection shows that the print lifted from the print head on one side, meaning the footplate is warped up in one corner. Throw out, try again!
     
    This is probably an issue with the print head levelling, which I triple-check before starting every print these days, as it's been so unreliable. Looks like I'll have to have another go.
     

  3. TurboSnail
    Along with the measuring thing that turned up yesterday were the PCBs for my prototype controller. The quality is pretty good for cheap Chinese-made boards, although I've noticed a few errors already! This was only ever supposed to be a prototype to run my test track though, I'll do an updated version when I get round to needing a controller for the layout.
     
    So now I'll have to find my SMD soldering tip and crack on. And think of some kind of case to put it in...
     

  4. TurboSnail
    A bit more development on the controller concept - PCBs have been ordered, so I'm doing some more work on the software. It's now set up to respond to the throttle using centre-off (so no clicking a reversing switch every few seconds while shunting) and it seems reasonably smooth. I had to incorporate a bit of a dead zone in the centre otherwise it was a bit twitchy - it seems pretty smooth now. I've also wired in a light-dependant resistor, which stops power to the track when it senses dark - fortunately this works, as the little Ruston would fall off the end of the desk otherwise!
     

     
    Stats:
    No. of lines of code needed to make this work: 55 (with extra spaces to make it easier to read)
    Correct resistor to use with a 20k to 2M LDR: 1k (this took considerable experimentation to get right)
    Cumulative pushup counter: 3325
  5. TurboSnail
    One of the potential solutions to the chassis issue for my 3D printed locos was to make frames from something else, with spacers - one of the materials tried is this laser cut Delrin - stable, low friction and pretty strong, and relatively cheap. However, it hasn't cut particularly well and is susceptible to warping, so I think this is a non-starter. Definitely worth an experiment though, and it provided the inspiration to try another method, which I think has worked well.
     
    There's also a set of gears cut in the Delrin - nice, but not quite perfect geometry, so they don't run quietly. I think this would work really well for bigger gears, where the kerf of the laser isn't proportionally as large. 
     
    The conrod shown is cut in plywood and is very fragile. I'm planning to try and reinforce it with something (wire? superglue?) and use them. Hopefully will be fine with some careful handling, certainly better than 3D printed efforts.
     
    I don't mean to sound ungrateful to my laser cutting friend! It's definitely a great technique that has a lot of applications, but I think the super-precise mechanical parts are maybe not the place for it. 
     

  6. TurboSnail
    Right, that'll do. Enough of this blogging nonsense! Finishing the Bagnall (for now) feels like a good place to stop. It needs varnish and weathering, but those will wait until the name and numberplates turn up. Overall, I'm pretty pleased with it, the modified bits have worked well, so I'll probably do something similar for more locos in the future. 
     
    Another project that's come up every now and then over the course of this blog is the AEC shunter, which now runs! Needs a flywheel adding to smooth it out a bit more, but I'm happy with where it is now, and looking forward to weathering it so it doesn't look quite so toylike. See video at the end of this post.
     
    But I'm stopping the blog here, mainly because I have to remember to post something each day, and if I have a less motivated day, or too much goes wrong, it just turns into trying to talk about nothing. So I'll go back to posting in my various threads, thanks to those who have followed and commented on this blog, I've tried to take onboard as much of the useful info as possible! If you do want to keep up with any of the things I've been working on, see these links:
     
    Workbench thread
    Layout thread
     

     

     
     
  7. TurboSnail
    I've been trying out a technique several people have told me to try, one which I haven't managed to get working in the past. For some reason, it now seems to work - don't know what I was doing wrong before, but at least it's another technique to add to the arsenal.
     
    It involves boiling water, and dipping the warped part of the print in for a few seconds. Then bend it to shape (with something heatproof) and hold until it cools down again. It's not perfect, you do end up with a slightly wavy surface, but it can make warped parts far less obvious. The buffers on this SER brake had a distinct upwards angle to them, but it now seems a lot better.
     
    I'm struggling to work out why this works though - the resin is cured, not melted, so I don't know why heat would soften it again. One theory is that the resin is actually a composite containing tiny thermoplastic particles, or maybe that it breaks down the cross-links just enough to enable it to move. That will remain a mystery!
     

  8. TurboSnail
    Today has mostly been tidying up - I've made a roof for the Bagnall out of plastic sheet and strip (some nice therapeutic old-school modelling!), added a whistle, crew, ungummed the buffers, and just generally tidied it up for final assembly.
     
    I've also fettled the AEC to make it fit its chassis properly and added a very bored-looking driver!
     

  10. TurboSnail
    Not a lot to report for today, I'm back to the CAD in a big way, with a couple of projects on the go that I'm not going to share for now... But good progress is being made, based around a couple of RTR chassis that arrived recently. I've also had more bits turn up to convert a couple of locos with custom chassis to belt drive, which will hopefully make them a bit less fiddly to set up, and hence more reliable. It sacrifices a little bit of smoothness, but I think it will be worth it for better overall performance. 
     
    The rest of my limited modelling time has been taken up with attempting to find ways of keeping cool - the weather was in the 30s all day yesterday, and my modelling desk/actual work desk is right next to a big window taking up an entire wall, that happens to get full sun from midday to sunset... So I had a dig around in my random items box and found a propeller, which coupled to a spare loco motor is doing some good. I also found an old solar panel in there, so that might get utilised too if I can find another prop. All of which shows you should never throw anything away (not that I needed this lesson)...
  11. TurboSnail
    Another project that's been stalled for ages is this Martley F Class, also known as the Second Sondes class. It was printed long enough ago that I was still using the orange resin, but has been sat awaiting a chassis before I build up the body any further. I never attempted building the original chassis design, as it was a long, 3D printed one, so would probably end up at warp city - this needs a redesign! I've got a couple of ideas for the frames, so this might be a good loco to try them out on. I've semi-proved the concept on another loco, but that was a 4 wheel drive Diesel, a conrod driven steam loco is a much harsher test. Getting the outside frames working will be "fun" too.
     
    I still think it looks alright though, this is one of my better prints!
     

  12. TurboSnail
    The Bagnall 16" takes another step forward - the majority of the painting is done now, the cab interior added, the chassis finished. I'm hardly the best painter in the business, but it's passable from 30cm away, and weathering should hide a few sins. Next jobs are to make the cab roof, add a whistle, and then wait a few months for the nameplates that are on order! I'm quite excited to get a coat of matt on this, which should make it look a lot better, then weathering, but I'll have to wait until I've got the nameplates and numbers for that.
     

  13. TurboSnail
    This mostly completed railbus has been sat around on my workbench for absolutely ages, just waiting for figures to add to the interior. Painting people is another task I don't particularly enjoy, so I did a whole batch in one go for this and two other locos. Then stuck the roof on, which is loaded up with lead to try and keep the unpowered front wheels turning. This works on the whole, so I'm happy to call it done and it can take it's place on the layout (once the layout is eventually done) as the workmans' train.
     
    The model itself is the KESR Ford, built from a kit I designed a while back. It's not the easiest thing to build and get running, so I'm not planning to offer it as a full kit, but if anyone wants a set of 3D printed parts for it, let me know and I might be able to make some for you...
     

  14. TurboSnail
    I've finally managed to print an SER brake without too much warping - there's still a bit, but much less noticable now. So here it is in primer. I've already broken off and re-attached one of the buffers, so I'll have to be more careful with the rest of it. Next job is to fit all the handrails, which is not going to be fun as there are a lot of them...
     

  15. TurboSnail
    So, no big question then. I've been struggling for a while to find a decent colour for the early SECR wagon livery - I've previously been using the darker grey here (though it looks a bit darker than it is in reality). However, the Illustrated History of Southern Wagons III suggests the shade was lighter earlier, before being made darker with the switch to the later Wainwright lettering. Other sources don't acknowledge a colour change at all, so it's all a bit confusing! The lighter shade I've used here is fairly similar to the Bachmann wagons produced a while ago, but lighter than the equivalent Hornby effort (though darker in reality than it looks in the photo! I think the phone camera artificially turns up the contrast a bit too much). 
     
    Have I got it about right? Or do I need to go back and find something in between the two shades?
     

  16. TurboSnail
    Now that the wagon is weathered, I'm much happier with the shade used, it's darker than it was. Unfortunately this wagon has come out in stripes! It was a reject from the current batch I'm printing for this reason, so it didn't pass QC. I thought I'd build it up myself to test the livery and the new brake design, and it's not nearly as bad as it looks in the photos, so will probably join the layout fleet. Not that I need another ballast wagon, I have three of these now, all in different liveries, and no requirement for a ballast train in my micro colliery! I'll probably be able to use one at a time as part of the shunting puzzle, so they're not all redundant.
     

  17. TurboSnail
    A while back, I printed some more experimental bits and pieces, to really test the limits of my printer. Here are the results - a few trees... Not much to look at really, but it illustrates the level of detail you can get out of a resin printer, at least when they behave themselves, which is not a high proportion of the time. Still, I need quite a few trees to hide the transition to backscene on my layout, so this will come in handy - and the useful thing is that I can scale as much as I like in the software, so everything isn't just uniform height. 
     
    I intend to make some with wire, and a couple of other methods too, for fun and to compare the results.
     

  18. TurboSnail
    Some experimenting with Revell paints this time - and overall, it's pretty positive. I've been using the enamels for the black on the Bagnall and the grey, brown and black on the ballast wagon (though the ironwork is done with a Sharpie!). All done with a brush, I don't own an airbrush. The paints seem fairly thin, but give good coverage, everything here has one coat only, though I need to recoat the black in a few areas where the primer got oversprayed with the main body blue. The next one to try out is the bufferbeam red - the real acid test, as I've never found that could cover in less than 3 or 4 coats so far.
     

  19. TurboSnail
    I'm in the middle of trying to print batches of wagons for people, and I'm getting some good results, but the printer is still trying to fight me! I'm still only at about an 70% success rate, which is slowing me down, and doing long days at work doesn't help, but we're getting there. I've been thinking about upgrading the printer for a while now, but I'm still well away from having the financial clout to do so - there's the very cheap hobby end of the market (about £300), the expensive pro stuff (about £3000) and not much well proven stuff in between. 
     
    In other news, that chassis I was working on in yesterday's post is going together well, and I'm in the process of building another ballast wagon to have a play with some new paints and to try and nail down a more accurate early SECR wagon livery. Just glad I have a nice relaxing hobby sometimes!
     

  20. TurboSnail
    I've come to the conclusion that the job I hate the most while modelling is removing lead weight from previously finished locos. It's difficult, potentially poisonous and there's a big risk of breaking the loco, as the lead/glue is often stronger than the loco itself. So far, I've had to attempt this with three locos - the only one that's survived is this one, so maybe I'm getting better at it. 
     
    Incidentally, the reason for doing this is that I'm fitting a new chassis to a different design, with a higher mounted motor. Which hopefully will run better than the last three or four chassis I've built for it!
     

  21. TurboSnail
    The SER 3-plank open needed a bit of weathering, so I took the opportunity to do my freelance Planet loco at the same time. A more lightweight job this time than some of my previous weathering attempts, to try and add a bit of variety - not everything will have been filthy all the time.
     

  22. TurboSnail
    Well, @Compound2632, it works again!
     
    Not too much of a complicated job, just failed to notice that not all the conrod screws were the same, which meant a lot of head-scratching until I figured it out. 
     
    Here's proof, complete with my flatmate's Call of Duty commentary in the background. 
     
     
  23. TurboSnail
    I hate having to repaint an RTR chassis, with all the risk of damaging it or gumming up the works etc. But still, it has to be done for the Bagnall to fit in with the rest of the locos, so here goes painting the frames, conrods and the under-boiler block (I picked one with the right colour wheels and cylinders to start with!). It's not actually too bad with the way Hornby have designed the Peckett B2 chassis donor, it's just a few screws, and no trailing wires to get in the way anywhere. Still pretty fiddly getting the conrods off though!
     

  24. TurboSnail
    More work done on the small building end, all the plasticard bits are now ready, but I failed to notice until I needed it that the tube of UHU is looking a bit sad, so that stopped play and I'll have to wait until a new tube turns up. In the meantime, I'll have to work out how I'm going to make the cutouts for the door and vent in the plasticard sections - they need to be much more accurate than the holes in the base card as any gaps will show. At present, the plan is to stick it to the card, then cut out a rough shape with a knife, then sand it out to the final shape with a sanding drum in the Dremel, but if anyone has any better ideas, please do let me know!
     

  25. TurboSnail
    The tiny Hunslet has had a simple change - from the original geared drivetrain to a belt driven one. The lack of a decent supply of tiny gears led to the choice to go to belt drive, even though the engineer in me protested. It's predicatably a bit more 'frictiony' now, but seems to work and is compensated for somewhat by the now lower gear ratio, so it's a bit slower too. 
     
    However, there's still one major issue with this loco. Weight! It's not heavy enough to get consistent pickup yet, so I'll add some lead in the bonnet, and a whitemetal driver. If that's not enough, we'll have to think about replacing the roof with something heavier, and maybe using some of the chassis too. I need to change those pickups for something neater too.
     

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