TurboSnail

I'm curious as to why you modified the chassis rather than cut out a section of the floor in the 3D print... Sem, how far out is the RailRoad Jinty chassis from the G6? If you want measurements, I can dig mine out - bought it a while back with a scratchbuild body in mind, but it might be perfect for something like this.

Do we get to see a test build at some point?

Yep, I'm using scale-link. To me, they seem like the best of both worlds, the self-quartering of the Romford style and the more detailed plastic centres of the Alan Gibson type. That they're also the cheapest is just an added bonus!

What are the running qualities like? Sure it's easy enough to add weight to. Incidentally, Budgie on the P Class page has just posted "I would love a set or three of SECR livery 4-wheelers. Who can we persuade to make them?". Not that you have enough to do already...

I just wish someone like Hornby would make simple chassis available as spares - Peter's spares used to sell the RailRoad chassis (chassii, chassises?), fully assembled as spares items, but they've stopped doing it as Hornby won't sell them separately any more. Would have been a great source of 0-4-0 (£14.99) and 0-6-0 (£19.99) chassis for kitbashing/RTRbashing/scratchbuilding. That's pretty much where I am too, I'm currently developing a 3D printed chassis for the Wrenn R1 because the etched/cast options are too much for me to afford. The full SE Finecast kit will cost about £110 before motors and gears are added - even though I'm planning to use the same (frighteningly expensive!) wheels, my chassis with a detailed Wrenn body should be less than half that. Will it be as accurate? No, but I'll be having more fun building it and playing with it than dreaming about maybe owning one after several months of saving As an aside, it's not just the modellers feeling skint, I'm in a hotel for a job interview and someone's nicked both the shower curtain and the batteries out of the TV remote!

The new gearset got delivered today, being used in my R1 chassis project, but you can see the difference to the old set on the left, all metal and much more robust. Managed to check the body on a standard Hornby 0-4-0 chassis too, so that would be a decent cheaper option, if not quite as smooth. The chassis will need a little modification around the sides to fit the narrower body as well as shortening. Just for fun, I also seem to have invented an outside framed Class 06...

Fox Transfers do a load of etched stuff, they might have something. If you can't find anything, I've seen people 3D print nameplates in high-definition materials and not look too bad, although they're still not a match for etched ones. Having said that, the LNWR plates look rather flat anyway, could you perhaps print them onto thin card or something?

So the T3 is considerably smaller than the Midland Compound? Did the same designer do a larger 4-4-0 that shared common parts like some of the SECR classes that you could rescale bits of it for? X2, T6 etc?

Not had much modelling time over the weekend, but the detailed version of the chassis is coming along nicely. Still need to add NEM pockets and pickup mounting points, then it's pretty much done. The bits in orange are not going to be 3D printed, and the body shown here is just a mockup of the Wrenn body. If anyone has any points for improvement, it would be very much appreciated at this point. Rivet counters may be a little upset - the rivet detail is as small as practical for printing in WS&F, so I can't quite fit the full number in. Some other parts are very slightly overscale to meet Shapeways' minimum requirements for part thicknesses, but most are accurate, at least to the drawing I'm working from!

Ah. This is why I don't use imperial any more... Is 3.175mm axles any better?

The R1s have an extra box of some sort under the front left corner of the footplate, I haven't managed to identify what it was yet though. Do you know if the Wrenn model has the earlier or later chimney? EDITED: because I can't tell left from right, apparently

Being 3D printed, it should be perfectly square! I'm designing the chassis to use Markits bearings with 1/8" axles and Scalelink wheels, and the centre bearings will be recessed to allow some sideplay of the middle axle when cornering. Coupling rods I'm not sure about yet, I'm going to try 3D printing them so they will be the exact correct length for the chassis, but if that isn't strong enough they will be modified from an existing RTR set. The test chassis shown earlier in this thread will have modified RTR coupling rods (from a 4F), so it will be a good opportunity to check it works. I recently finished a 3D printed 0-4-0 diesel shunter and the hardest part of that was getting the RTR coupling rods to work with the 3D printed chassis as there was a slight difference in length, hence why I want to 3D print them this time to get the lengths exactly the same.

Thanks, those photos help show the spring location, which is a bit tricky to see in photos. I have bits and pieces of the hardware already to measure up so I can get the locations as close as possible first time, so i shouldn't need to do too many test builds. This conversation was had a while ago on my blog, the consensus being that the SE Finecast one is slightly wrong, but much better than the HD one. If you want super accuracy, the Branchlines one is the way to go, but then it makes the body's inaccuracies show up more obviously. So I'm going for something of a compromise, as I don't want to do major work to correct the bodies, but the wheel spacing will be correct. To be honest, if I wasn't detailing the body, I'd just re-wheel an original Wrenn chassis, as they seem to run pretty well (at least, mine does).

There will be guard irons and brake detail on the next version, this one was a quick test print on a low quality printer that had no hope of recreating such detail accurately - it was just made to check the overall dimensions are right. The frame outline is correct though, at least according to the drawings I'm working from. It does look a bit sparse without the detail though, so I'm backing up the drawings by working from photos, particularly this one (copyright to railway-photography.smugmug.com): I'm modelling the more detailed version at the moment, with bearings included. Finer details like piping and brake rods will be done separately with wire. I'm more aiming for a good running loco than for absolute accuracy as the body will still be Wrenn-based, so there will also be plenty of space to add weight to the chassis as well.

This has reminded me that I need to make a proper micro roundy-roundy some day... Mainly so I can make up my own wacky and wonderful rolling stock. Would that be a Kato chassis you're using or something more home-made?

See the post above for that fix - I ground away the raised section, then covered the hole with paper, reinforced with PVA. It's not ideal as I didn't grind enough off in some places, but it's better than it was.

What are the parts needed to complete a kit? I'm thinking wheels, bearings, buffers, couplings etc.

This poor R1 has had some butchery surgery done to it in an attempt to correct some of the more glaring issues. Still got to do handrails and possibly a basic cab interior. Anyway, the chassis fits! Pretty well too, considering the fairly relaxed dimension tolerances of the PLA printer. The 4F wheels are slightly oversized and shouldn't have balance weights on, but they'll do for a test fitting. Here's the thing though - does it look like an R1 to you? This is the stage where I need as much feedback (on the chassis) as possible so I can make the CAD model as good as it can be. P.S. well done if you can spot the two deliberate errors!

I'd found that one, and the Branchlines one, but for a number of reasons I'd rather make my own: - 3D printing means no soldering needed, so I can't assemble it wonky or misalign anything (the main reason as I want to be able to make several with the exact same performance) - I can use any motor (and probably flywheel) I want, which will be cheaper - I can use any gears I want (I'm going for 1:60) and it won't need a separate gearbox etch - The layout can be tailored to the body, especially useful if I'm making an R class with a different boiler, so I can make sure everything fits where I want it to - I think I can make it cheaper And finally... I'm one of those odd sorts who likes making stuff this way! CAD is fun (usually), why would I let someone else have all the satisfaction of designing it?

Certainly can! Would be nice if someone else is able to use it. Should be able to be adapted in CAD to suit different wheelbases for other classes as well, though I haven't looked into this yet. Stay tuned, I'm working on that today, though my solution is probably not the most elegant... I'm eventually planning to mod some Wrenn R1s into unrebuilt Rs, which have a different boiler configuration, so would replace the entire boiler with plastic tube in that case.

I'm embarking on a new project, to make a relatively simple to use replacement chassis for the Wrenn R1 class. I'm hoping to model Folkestone Harbour type formations in the future, so I need a few of them that I can make in a consistent manner with the same running properties, so they can be triple or quadruple-headed. I'm also planning on detailing the R/R1 classes (also in this thread), so I need the motor to be out of the cab and the allow visible daylight under the boiler. The wheelbase will also be scale accurate, at least where it is possible while still working with the Wrenn body. The first prototype is being made now, printed on an FDM 3D printer at my Uni, so won't be the highest quality. It will get used to check the general arrangement is correct before ordering the detailed ones from Shapeways. I've got some Hornby 4F wheels to try it out with so I don't have to spend too much on it, and if it works well, I'll add some detail and make it into a 'dummy' unit. Had to do a little bit of reinforcement on the motor mount as you can see in the picture below, mainly because FDM printing is very weak in the horizontal direction. I've also moved to a different (bigger) gearset since this image was taken due to the issue I had with it on my recent freelance diesel shunter project.

This page might help you: http://www.doubleogauge.com/standards/couplings.htm Not sure any of those evergreen sizes fit, they're all too wide I think.

Plenty of people have heard of REL Maunsell's forays into diesel shunter design, with no.s 1, 2, and 3 being developed in 1936/7 with 350hp engines to compete against the Z class heavy steam shunters. What is less known is that late into the design, it was also decided to trial a smaller 0-4-0 version with a 200hp engine, to replace the likes of the A1X and R1 classes in smaller dockyards and branch lines. As such, the design was outsourced to an industrial manufacturer (there are very limited records of this engine, so the identity of said manufacturer has been lost) with instructions to maintain the key features of the larger 350hp engines, including the distinctive angled lower cab windows, step/handrail locations and the outside frames. Only one locomotive was produced, no. 4, finished in 1938, and immediately sent to the Elham Valley line where it proved useful but at higher maintenance and running costs due to the unfamiliarity of the crews with the new technology and the cost of getting diesel to the rural location. After the breakout of war, it was transferred to the Q port at Richborough, which is where the trail stops. It is possible that it was sent across the channel as part of the war effort, but given it was a non-standard class, I think it is more likely that it would have stayed there as a shunter and that any further records of it's actions were kept classified or lost, leaving the enticing (but unlikely) prospect that it is still out there somewhere... Only one known image was taken of it, believed to be somewhere on the Elham Valley line. Of course, that's all complete rubbish, this post was supposed to go up on the 1st April, but I'm nothing if not willing to jog along several hundred yards behind the bandwagon... The loco in the badly photoshopped pic above is based on the backstory above, but never actually appeared in real life. I needed an excuse to practice with 3D printing, without people pointing out all the prototypical inaccuracies that would go with an existing locomotive! You can see more of the results in the video below - please excuse the 'advertising', I'm not expecting many people to want a model of something that never existed...

The engine is starting to come together, or at least half of it, the rest provided by the mirror.

Returning to this much-neglected project while I have some free time. One of the other main reasons for making a CAD model of the whole thing is that I can make scale templates for things like the engine frame, here being cut from 0.5mm plasticard. Much easier than trying to transfer dimensions by hand.