Keep in mind that a 'tongue switch' does not need to be a single section of box, or fixed curve as in the monorail switches. It can be a series of sections, jointed the same way sections of an airport luggage conveyer are, and the SAFEGE- style carriers can have horizontal articulation, Ackerman steering, etc. so the vertical rubber-tired support wheels can follow the edges of the slot. Note that the force required to guide the vehicle is relatively slight compared to the force needed to suspend it, so the horizontal 'stabilizing' guide apparatus and its corresponding track surface in the sides of the box can be relatively small (as on the old Paris metro from which the SAFEGE bogies were derived) and the force needed to turn the vehicle on curves is a function of momentum and not dramatically greater -- for a model, likely less than on a scaled prototype.
The problem with coned wheels (or angled support tires) is the outward thrust on the lips of the beam slot. It is difficult to design reinforcement at those edges, whereas applying lateral guidance up near the top of the box takes best advantage of inherent strength.
The best solution for ground taxi is likely to be guide magnets in a track or tracks under the 'pavement' (this can be one of the existing systems for boats or vehicles on model-train layouts). The catch will be coordinating the taxiing behavior with the action of the support cables; I suspect you will not want slack in the overhead at any point, so it might make best sense to keep the 'landing gear' a mm or two clear of the runway pavement and let mutual magnetic attraction control the swing of the fuselage relative to the 'nosewheel' and mains.
While you won't need the real-wield primary compliance of pneumatic tires in the model system (as a full-size version would) you will still likely benefit from elastomer material on the support and guide wheels, if only to lower distracting noise.
Very interesting ideas, and I think you've begun to reverse engineer my "secret" idea! Regarding the SAFEGE track, I finally found a .gif image of a tongue switch here:
ShonanSwitch.gif (112×150) (monorails.org)
I see the tongue has a vertical wall against which the sidewheels of the bogies would push to turn the whole vehicle I'm guessing. I haven't sketched it out in 3D yet, but I'm having difficult convincing myself that such a switch would work if the turnout is a very sharp corner (like where an airplane taxis off the runway after landing). I was starting to consider a modified SAFEGE/H-Bahn - instead of using rubber tyres, I might use coned steel wheels that use the edges of the SAFEGE slot as the railheads. Any reason that idea might not work?
Another question: Is there an off-the-shelf CBTC software for the model scale that can independently control many different vehicles within the network simultaneously? I'm thinking it might be useful in creating "moving blocks" around each taxiing aircraft, as well as coordinate the overhead suspension bogie with the ground-system. I was thinking of using electromagnets embedded below the tarmac to either:
a) help steer the magnetised nosegear during taxiing whilst the overhead bogie+fishing lines slowly pull the plane forward. The software just has to activate "blocks" of electromagnets whenever the plane reaches a location where nosewheel guidance is necessary, like at any turn; or
b) activate the current through the electromagnets so that those electromagnets would be the ones pulling the aircraft forward via the magnetised nosegear, and the overhead bogie+fishing lines just passively follows along during taxi. In this case, the fishing lines would be slack to allow the airplane to turn unencumbered, but will tighten when it comes time for the aircraft to take off. The software would have to finely control which electromagnets get current to move the plane forward, but the overhead bogie would have to coordinate its own location to wherever the active electromagnets are.
Thoughts on which idea for propelling a taxiing plane is better?
Coming late to the actual party:
I was presuming this was not a model system. Having now carefully read the thread, it looks as if this is an animation system for physical models.
Very little 'technical' information is necessary to understand either SAFEGE or SIPEM as far as the actual guideway tech is involved -- it is a hollow box beam with a slot in the bottom. A bogie runs inside the beam with rubber-tired-primary-suspension wheels riding on leveled contact surfaces either side of the slot. In the SAFEGE planning, IIRC, they were using '60s Paris Metro components for most of the "mechatronic" stuff.
Switching is done basically by moving or turning a box section between two routes - a bit like a Lartigues & Behr monorail switch turned inside-out. This is cumbersome but not showstoppingly difficult; the principal concern is that all the approaches and the moving beam have to be shaped so there is no sharp change in curvature for the bogie to catch on.
The fun thing your design would add is 3D "Z-axis motion" which for a model plane system instantly implies beam tracks large enough to accommodate substantial winches with some reasonably invisible-to-view monofilament or fine wire. The beam would constrain the ground track of the aircraft whether in taxi or in flight: crossings between beam routes would be possible but require something like active-frog-style extension of guideway for shallower crossing angles, and not at switches, for example.
You'd probably use only one rail, over the centerline of the aircraft path. This will contain two bogie assemblies, each articulated with enough wheels and suspension to take and guide the weight of half the aircraft plus load, perhaps with redundant line. The simulation of sharp departure angle, or landing flare, should not be impossible with this system. The winches could be put in the aircraft models themselves; see below for how to power and control them.
The concern that emerges now is that the bank for noise-abatement turn has to be generated by a laterally-moving or sliding weight, and this and the simulation of control-surface movement, flap and reverser deployment, etc. needs to be powered. You could use some combination of battery and wireless charging to do this, for example proximity Qi-style high frequency induction in the 'hidden' part of the track that carries the invisible "departed" planes around for staging and then eventual "rearrival". The alternative is to run power through the fine suspension wires.
Some of the advantages of DCC model-railroad operation could be used for this system, as could some of the wireless control systems.
A separate system for precise ground control does make sense (you would have to coordinate it somewhat with the overhead system to allow just the right slack moment-to-moment) and magnetic engagement would be an appropriate technology. Are you wanting to simulate taxi to gates, jetway extension and retraction, and pullback with a tug? Those should all be possible with the right 'ground system' although the simulated tug would probably be better done as a RC vehicle than a Faller-style device on its own track (but see the YouTube video where a ferryboat crosses other magnetic-track systems and its own path... proving that both can be done).
I am tempted to add that the current state-of-the-art with e-ink should allow a 'skin' on the aircraft models to allow dynamic albeit slow reprogramming of aircraft livery, so departing and arriving planes can appear quite different even if only a small number of physical planes can be in use.
Speaking buisness here, though you are thinking in those lines, we are talking about a capital intesive and a return on investment that would not lead to compitition unless you invent something that has comertial value.
ROBERT PETRICK louiej5 Hi there, I'm sort of having a pre-midlife crisis: I want to build a highly customized "rail-borne" system that I doubt has ever been designed before, but I don't know if I have enough time to learn everything I need to do it. I also don't want to be sidelined in a team for being the least knowledgeable. I don't know where to begin . . . First, welcome to the forum. Second, this is an interesting idea. Third, regarding the highlighted sentence . . . as long as you pay the bills you will not be sidelined. Fourth, if you need help, just ask. There are many talented and knowledgeable members on this forum. You might have to divulge a little more info if you want meaningful advice, though. Fifth, you might want to check with the legal department of your current employment. Many engineering firms have proprietary and non-compete clauses in their standard employment contracts. They might not be too generous with what you do outside the office. Some firms might think they own everything that comes out of your head. Sixth, good luck. Robert
louiej5 Hi there, I'm sort of having a pre-midlife crisis: I want to build a highly customized "rail-borne" system that I doubt has ever been designed before, but I don't know if I have enough time to learn everything I need to do it. I also don't want to be sidelined in a team for being the least knowledgeable.
Yep, as soon as I fabricate and publish a simplified mockup of the descent-bank-approach-land system that proves the concepts workability, I will divulge all details in my head.
I guess I'm afraid of someone with a more mechanical background can steal my idea and build a mockup faster than I can. But on the other hand, I'd still be happy that the project would be realised anyways - just not by me.
cv_acr I don't understand the goal here. Is it a hobby project, or an attempt to create a business/tourist attraction? If it's just a hobby (enjoyment) thing why are we talking about being sidelined on a whole team of people?
I don't understand the goal here.
Is it a hobby project, or an attempt to create a business/tourist attraction?
If it's just a hobby (enjoyment) thing why are we talking about being sidelined on a whole team of people?
I'm envisioning both: it's my hobby, but I hope to turn my hobby project into a tourist attraction. I hope to find a Hong Kong museum willing to lend or rent enough space that I think might be larger than Knuffingen airport.
I'm definitely going to find people to help me, but I want to make sure I am competent enough to have an important place for the duration of the project life cycle. Not just someone who has an idea and just dictates to other people what to do.
Inspirational! Thanks Northbrit.
Thanks everyone for your replies! Lots of inspiring photos of very unique model train layouts that I've never seen before, like that giant train machine, or that maglev. Those aren't things that pop up on my googling often.
I do have a concept in mind for 90% of all the components for this project, so I know it's physically possible to realise. Just designing and fabricating a simple mockup how planes would descend, turn, approach and land seems daunting. I guess I'd have to experiment a lot.
I cannot help you as such louiej5 because I do not really understand what your final plan is, but what I can say is if you visualise what you want it will happen. Just do not let anyone 'take the idea away from you'. Because people will say it cannot happen.
Here are three things that amaze me.
Theoretically this should not work, but seeing so many moving parts as it travels the track is unbelievable.
The next picture, apparently the train uses a Maglev system.
The next picture I just love and it fascinates my grandchildren
Why have I posted these pictures? Because the people who built them had an idea and followed it through; not letting anyone say 'It cannot be done'.
We have a saying here 'Dream BIG dreams'.
I believe you can do it, (even if I do not know what it is. )
David
To the world you are someone. To someone you are the world
I cannot afford the luxury of a negative thought
A bit more information on the Gulliver's Gate airport. The architectural design was done by Gradient Architecture Studio of Brooklyn, New York. They might have more information offline if you contact them.
It takes an iron man to play with a toy iron horse.
Going back to school for a hobby?? I would say no. Learning is part of the fun - just don't go broke buying supplies.
Would you be doing this for a museum? If yes, they may have funds. You can let your employer know. Unless you work for a firm that sells exhibits to museums, I doubt very much that your employer will object to that (although you don't mention where you are located - Hong Kong? - local labour laws differ). In Canada, an employer cannot prevent you from holding another job in your spare time, except if it's in the same line of business as your employer, or if conflicts your work in some way. Don't know about other jurisdictions. I suspect it is the same in the US.
Simon
LINK to SNSR Blog
Chris van der Heide
My Algoma Central Railway Modeling Blog
Professor Milankovic is an expert on complicated mechanism-- I would PM him for conceptual assustance
Gulliver's Gate was a short-lived 'permanent" project which created miniature scenes from around the world. It was in HO scale, and there were HO scale trains with appropriate nations' railroads, all running on simplistic loops under DCC. The New York City exhibit included a working model of LaGuardia airport. They were still working on that when I got to see the exhibit. Unfortunately, they couldn't cover expenses and the exhibit closed. At this point, I can't even find their web site.
Miniatur Wunderland in Germany is still running, and also has a working aircraft system.
Gulliver's Gate used their own system to 3D print aircraft components, assemble, paint and decal them.
This was a large effort.