Skinnylinny

Haha, well, Sunshine on Shandwick Place in this instance, but yes!

I too collected mine from Harburn. With the beautiful sunshine in Edinburgh yesterday, I couldn't resist a quick snapshot while waiting for a tram...

The frame now has lever numbers (Also 3d printed), and work has started on printing the block instrument. All the circuitry fits inside, although I've had to temporarily substitute momentary toggle switches while I await the push-buttons arriving. I've also set up a temporary trackplan board to make testing easier. Now to decide what type of wood veneer to use - mahogany or cherry. Or possibly walnut. All three are rather nice! I ought to start thinking about signals, I suppose...

It would, although I lack the required woodworking skills, and no longer have access to the laser cutter since moving to Glasgow-ish. GrandOrgue at the moment, as I don't have the cash to drop on a copy of GrandOrgue, and I'm sort of cautiously dipping my toe back in for as little spend as possible. The 61-key MIDI keyboard cost me £60, while the pedalboard has cost me the grand total of £1.04 on eBay and the price of a decent takeout dinner for a friend to drive it up to me! It will require a bank of microswitches, and the use of an Arduino which I already have, to MIDI-ify it.

Bells-wise, I'm leaning towards a speaker and recordings, to be honest, rather than physical bells. I love the idea of operating with them, but I daresay my neighbours would appreciate the idea of a volume control. They've enough to deal with now that I'm getting back into organ practice too (well, as best I can with a MIDI keyboard, and an old church organ pedalboard that I've managed to acquire and am planning to MIDI-ify...) but at least that I can do on headphones!

So i was sitting playing with the lever frame, and got to thinking. It's all very well having a frame, but what use is it if the next box down the line can't communicate to send me trains? Now, I could just rely on talking to the fiddle yard operator, but where's the fun in that? So, I've been playing about a bit more in CAD. I've not yet decided how to drive the arms, but I'm leaning towards servos unless I can find a way to hook this up to some solenoids in such a way that I can drive it on 5V or so. It's to a larger scale than the levers in order to be visible to a 1:1 operator, and I've yet to decide how to sort out a pegging handle. The outer finish, however, I've decided on. I have some rather nice self-adhesive veneer, which should look rather good over a 3D printed case, perhaps with some suitable decorative wooden mouldings.

It lives! Well, all the levers, microswitches and locking are printed, assembled and working. Unfortunately, the 2mm threaded rod I ordered for attaching the microswitches is... subpar... The M2 nuts just slide along it rather than "biting" the thread! I may have to look for another source. There are still a couple of minor bits that need tidying (like painting the handles on some of the levers) or that may get changed - the strengtheners to the catch rod guides, for example. There's also a very slight occasional issue with the tappets binding slightly between the quadrants - this may settle down as bits bed in, or I may have to adjust the tappets slightly and reprint, but all in all I'm very very pleased with how the project has turned out! In the meantime, I've been working on something more modern - the ScotRail class 334 for the club's forthcoming Haymarket layout. Awaiting varnishing before I grubby up the roof and add the cant rail stripe, then do the glazing.

Just wanted to say thank you to @m0rris - I bought a class 334 a few months back, and have finally got to the point of painting. I'm delighted with the model, and very impressed - it's well detailed, weighty and the resin used is nicely flexible, rather than brittle. Just enough to get the wheels into the bogies (although I did find them a little snug, but easy enough to ream - always better that way than too loose!). I'm really enjoying this build. Next thing on the to-do list is figuring out where to get a suitable pantograph, and sorting couplings between the cars.

Once everything is in place and tested, I intend to have a clear piece of acrylic over the top.

Getting there... 4 more quadrants, 6 more levers and one more locking bar... and hopefully that should be all the bits I need to assemble the whole thing!

Hi Michael, So the pivots on the catch handles are M2 bolts, which pass through one side of the catch handle, and self-tap into the other side of the catch handle. The catch rods do have springs attached to the bottom where they pass through the quadrant. The springs hook over the hooked "leg" to the left of the lever in the picture above. They're fairly softly sprung, but enough that the catch falls reliably. I am not expecting many guest operators, and the long-term plan is to have a mimic panel as an alternative method of control, that can be plugged into the same electrical connector that will attach the levers to the layout - the levers are mainly for my own enjoyment. That said, there's a *little* flex in the catch rods, but only enough to allow maybe 1mm of movement at the very tip of the lever handle.

Well, the printer's been on the blink for a little while now - it suddenly started producing plastic spaghetti instead of lever frame parts. About 8 hours of tinkering later (spread over about a week!) I've managed to get it working, and I now have an idea of what to look for if it fails again. My first successful print was the locking bars, and there are now the first ten tappets on the print bed. I've also been playing around with how to mount microswitches, and I think I've got a nice neat system which should do the trick, having stolen the basic concept from @Lacathedrale's suggestion a few pages back. Every third quadrant will have this tab with two holes in, to fit more threaded rods (M2 this time, rather than M3) to support microswitches. It *should* be possible, with care, to route the wires neatly downwards, although I may draw up some kind of cable trough for them. While the interlocking may be mechanical, the levers themselves will operate the microswitches and thus, indirectly, the signals and points through servos. I'm also hoping to add coloured strengtheners to the lever catch rod guides at some point, but for the foreseeable future I'll be printing lots and lots of black parts (interlocking and more quadrants!)

What's wrong with "embiggened"? It's a perfectly cromulent word!

Well, a fair bit of finagling later, and now things are stretched such that the tappets' throw is approximately 1.5 rows, thus stopping the problem. Whew! Now to try printing the bloomin' thing!

Oh, I think I see what you mean - there wouldn't be any movements from the down platform across 3 unless it were reversed, so the FPL on 4 only needs to lock 3 in the reverse position. Very smart! I am a little worried that one port in tappet 5 (that's on row B when normal) will be rather too close to the dog on the green bar - this could allow the following sequence of lever movements (that I don't want!) Starting all N 3R 5R 3N (while 5R!) I must say, I'm glad I'm not doing this for a living!

Hmmmmm, I was *hoping* to allow simultaneous arrivals and departures, but I would definitely rather avoid conditional locking! So something like this? (I realise I've done the lilac bar in sort-of the opposite way to usual, but that's to avoid clashes with other ports in the same tappets). The only niggling thought in the back of my head now is "Should 5 be locked normal unless 3 is reversed?" Thank you so much for your help, @Nick C!

Much better! Just lever 20 to do now...

Now there's some lateral (quite literally!) thinking! Thank you! It would still fit in with the general layout of the diagram too - I shall do that. Thank you so much!

I've tried to arrange levers that mutually lock/unlock each other fairly close together, while still having them in a logical order for the signaller. I'm still not finished yet, but I think I'm getting pretty close. You can see there are quite a lot of very short locking bars. The orange locking bar is annoying me because it's blocking an entire row. It might end up being placed "upside down" atop the pink top bar, freeing up the row for the locking of lever 20. There may well be errors, but the plan at present is to print the whole lot, test it, and then edit as required, as the brain fog has been hitting lately.

I do expect the parts to wear over time, so yes, I've been building the whole interlocking setup in CAD such that any one part can be re-printed if worn. I hope that the forces involved should be rather less that that inflicted on a full-sized lever frame, too! If money were no object, I would love to get the interlocking (and the levers) CNC-machined from metal, but I'm running on a relatively tight budget. At least with the 3D printing, it's easy to change things when I inevitably make silly mistakes. For example, the first time I printed a locking bar, I had managed to design the locking "dog" such that it locked both levers and neither could move! Fortunately, 20 minutes later I had a new one, and all worked smoothly. Lever 1 (distant) is locked normal unless the home (2) is reversed, and reversing lever 4 (FPL) locks lever 3 in either position. Incidentally, in this photo you can see the surface finish that "ironing" has on flat horizontal surfaces. They certainly slide over each other much better! I've decided that I will number the tappets when printing them, in order to make assembly easier, as can be seen on tappets 3 and 4 above. Now, I need to finish the locking table before I can get much further...

Whew. It's been nearly a week since Model Rail Scotland, and life is nearly back to normal. Unfortunately, I rather over-exerted myself the first two days, and the chronic fatigue syndrome reared its ugly head, with 'flu-like symptoms, on the Friday evening. Indeed, the glands in my throat were so swollen and sore that I could barely swallow. However, lashings of ginger-and-honey tea and the Good painkillers, and 25 hours' sleep between Friday evening and Sunday morning meant that I was feeling well enough to make it back for the last day, even if I did have to take things easy. It was wonderful to meet with friend old and new, including @Caley Jim (who brought one of his 2mm FS scratchbuilt Caledonian vans to compare with the Rapido 3D-printed prototypes), and meeting @Citadel for the first time. Forgive the broken door rail - those parts on the real wagon will be etched, and are exceptionally thin to print! The shopping list was very short this year - I picked up a bogie caboose kit for the American HO stock (well, at £3, it would have been rude not to - it even had pre-formed grab rails!), several sets of wheels for forthcoming wagon projects, and a £6 Cooper Craft GWR V1/V5 cattle wagon kit, to be painted blue-grey and run with the Titfield buffet car and Toad. Now, all I need is a 14xx... I've also done a successful print of some parts for the lever frame interlocking. This was a test piece, keeping the distant lever (lever 1, to the right in the photo) locked at "normal" or "caution" unless levers 2 and 3 are reversed (clear)). Yes, I know that lever 3 is a points lever here, this bit was a proof of concept! Now printing is a slightly larger locking tray, and another type of locking; this time, a facing point lock, such that when lever 4 is reversed, it locks lever 3 in whichever position it's in at the time. Mighty oaks from little acorns grow, and all that!

The hooks for the catch rods have so far not been too fragile, as they are only ever acted on by fairly weak springs. The difficulty is been having with the catch rod guides on the levers is that the 3d printer layers can, if the lever is pulled on without operating the catch handle, delaminate causing the end to snap off. A possible solution would be to carefully solvent weld another printed strip over the open side once the catch rod is inserted. This does trap the catch rod permanently though. The printed strip would be printed with the layer lines oriented differently in order to give added strength. I like the idea of the microswitches on a "girdle" - if I'd known you were going to attempt to edit the files in Fusion I'd have sent you the Fusion files as well as STLs! My only thought with mounting microswitches like that is that there may be a fair amount of flex in the 2.5mm rods over their length, which might result in unreliable positioning. Perhaps inserting similar mounting holes every few quadrants might help with that. I'll have a look, thank you!

Thank you! I drew it up in Microsoft Paint, using various photos of Saxby & Farmer diagrams as inspiration. The idea is to eventually trace it and do it "properly" with waterproof black ink and watercolours... Source: https://www.gwra.co.uk/auctions/gnr-signal-box-diagram-humberstone-station-diagram-2017nov-0045.html

There's still a few bits I need to work on with the levers - as you've probably either found (or will do!) the printed catch rod guides aren't *super* strong, and can be broken off if a lever is tugged against the catch. I may look at getting some of the parts CNC machined in metal. For now, and for testing the interlocking, they suit nicely! The system I have in mind for the actuation will likely not get designed properly until after Model Rail Scotland in Glasgow later this month, as I've got a lot of things on my plate until then, I'm afraid. The lever frame is still very much under development.

I haven't, but I am familiar with working out the locking... the problem is I was about 80% of the way through working out the dog chart! Ah well, at least there's not *that* many changes to be made...