As regards location, I was certainly looking at the Peaville line last time I had the trains out (2007?). Blue skies, yellow sand, and pink ballast! I guess I'm just miffed that ATSF never got to Tucson. This time I have started researching bits and pieces of ATSF and New Mexico and Arizona; even just trying to work out what cars I need and can justify buying/running. I really have no idea what was usual for the ATSF in Arizona in 1995. And I can't just wander outside to look Our trains around here are very different - 20' and 40' containers single stacked on flat cars, no well cars, no 53' containers. 3'6" gauge does mean tight curves and shallow tunnels, so I doubt we'll ever see double-stack down here. So far I get the impression that there should be unit/block trains of Coal; Hot Shots of Containers and double-stacks, with the odd TOFC in there; and then a local / manifest of box cars, flat cars, covered hoppers, tank cars. There's a fair few chemical industries in NM apparently, each with their own needs from a railway
Mine is more of a nolix than a helix. I designed it so that it was unidirectional (one way in and one way out), one control block to avoid power conflicts, diodes with a pushbutton bypass to prevent accidentally reversing out of the yard instead of forward, lockouts on full tracks, occupation lights when a train is positioned properly all the way in, lit pushbuttons on switch position, etc., etc. I threw every trick I knew at it and it's paid off- still working reliably today. These are the old construction shots. Note I put the switch throats out where I could get at them for maintenance. All the fascia edges are hinged and drop down to get into the yard and track below the main layout for maintenance. http://www.randgust.com/atsfplan.htm In theory, I could lift off top levels in an emergency. That was not practical. But in most places I've got 5-6" between the storage level and the top layout level. The mid-level Phoenix reverse loop works so that a train is either turned when it's coming in, or turned when it's coming out - again, one way in, one way out, occupation lights and automatic polarity reversing. ALL the scenery over top of Phoenix lifts off. The visible main line is bidirectional CTC signaled, and if the Williams Jct. switches are thrown, not only are the pushbuttons lit, but the home and approach signals on the layout go to either red (if a trailing point switch is set against you) or diverging clear if you're set to either drop down to the yard or go through the Phoenix loop. The layout is well finished, but we're talking storage design, so this is what I came up with. I can prevent most catastrophic accidents except accidentally throwing a power switch under a moving train at Williams Jct or at lower Chila Wye (which is no longer a wye -it was simplified to just the reverse loop portion and the one storage track was brought down to the lower main). When that happens, about once a year, it's a good time to turn off layout power, go upstairs, and have a drink, and come back in a couple days. Lots of finished layout video out on YouTube, search for 'randgust'. If you don't already have the McMillan Santa Fe books on New Mexico and Arizona, you want to get them for inspiration.
So I made a thing.. More specifically, I mocked up the size of the helix, using bits of wood clamped in free space about the right sizes, and then cut the middle out of a perfectly good sheet of paper. The hole is 28" wide and 41" long, 14" radius plus 14" straight. Some experimenting with a plank of wood (shown) suggests that 24" is about the narrowest I can poke my shoulders through, meaning I have 1-3" on the inside of the inside track to use as a bench for storing tools and building anti-flight walls and foam landing pads. 70cm is a crawl under. And not worth describing in polite company. I can manage it, probably for another decade. Too low for a wheelie chair; so I might go find some skateboard wheels and make me a little runaway tray. The concrete floor might also get some sort of mat for my knees, and the underside of the helix will be padded! Staging Deck Trackplan Alternatively: no-one ever said risers on L girders had to only go up... I could quite easily move the staging track up closer to the main deck, and hang risers down from the L girders to hold just one or two tracks (i.e. not the four shown in my current trackplan), and keep the "reverted loop" functionality while compromising some of the under-layout shelving due to having trains in midair "above the shelf". (trains are more important than storage space, right?) I will still have to come down below the L-girder itself, both for finger-room to fix trains, and also because the reverted loop passes around one leg, so it "intrudes" on the L-girder. And I suspect notching the supports for the main deck is the opposite of sensible! So I figure about 11" or more below the main deck (instead of 24" from deck to staging as currently drawn). So, if I raise the staging deck height, I have fewer turns for a stacked helix; or, a quick scrawl on @ppuinn's spiral helix tables suggest 14R minimum, 2% slope, 1.25" bed (single track) will get at least 11.7" before it slams into the table leg and thus intrudes on the L girder with a 39" footprint It might be possible to "finagle" a few orbits above the table leg/girder height, and make a bowl helix fit the space. 2" grades across the layout with flat sections for the major scenic blocks / vignettes gives me 4-5" of climb possible; two laps of my stacked helix so probably two laps of a bowl too. ... And the trackplanning discussion appears to have hijacked this thread One week of work until Christmas, and after that I get three days with no family, no parties, no obligations, so I might get some more layout work done this year
A little ahead of schedule, I screwed the L-girders to the legs, using copious clamps to hold everything together. I am quite fond of my 6' yellow level. It is taller than I am! (just) Not very photogenic, so I staged some rigged demos instead . So I guess next is either get the printer working, or make a 15" compass and start playing with 1:1 track plans for space and reason.
Probably the most spectacular helix I've ever seen was on Jerry Britton's PRR and it was a work of art - two tracks, big, took the staging yard down to about two feet off the floor where the normal table height was about 48". He wanted easy overhead access to the switches in the storage yard and maximized overhead clearance. It looked pretty difficult to get under the helix but he had outside access to about 90% of it - didn't look critical to get inside. But wow, a train ran just forever from staging to visible track. There's always a trade-off on vertical clearance vs. time on the helix. Just assume that anything that can possibly go wrong, eventually will, your switches will fail, track joiners will oxidize, everything will derail at least a few times, and you'll have to be able to figure out how to fix it. My last hidden yard I designed (a little two-track industrial stub that goes right over top of the Phoenix loop switch) is built so it is entirely lift-out to gain access underneath. It was worth the extra work to design for the inevitable - either cleaning the two-track yard or pulling debris out of the switch underneath. My most catastrophic derailment of all time was on the downhill 2.5% down to the storage yard where a truck pin worked loose on the very front of the train, dropped and lodged in the ties, and made a ramp derail for the rest of the entire train to go off the line, gravity fed, over the edge, and on the floor. All 25 cars. And then I couldn't reach the stupid truck pin to get it out. That's only happened ONCE, but I'll never forget it. So your efforts to catch or cushion cars is worth it. My under-layout clearance is 48" at the duckunder and I'm already preferring to use a low office chair to roll under it instead of actually bending over. I think any of your options are equally good, and if it weren't for that double crossover in there on the helix design, you'd have very little reason to ever have to get in there at all. I'm amazed how well a good, heavy train with 3-4 powered units on it can keep the track polished up. A Kato powered ABBA set is capable of removing just about anything including spiders and sawdust piles from the rails.
There's no rule that says you MUST use the same L-girders to support your decks as you use to support your helix. In this pic of my Peoria Helix, the top edge of the lowest piece of fascia is at 48 inches and the L-girders for helix are behind that fascia. The middle fascia (middle of left side of pic) is covering the L-girders for the lower deck of the peninsula, and this fascia top edge is just over 52 inches. The padded L-girder in the upper left corner of the pic supports the shelf which forms a 56" high duck under and is attached at right angles to the upper deck L-girders of the peninsula and the L-girders for the upper deck of the shelf on the wall behind me. This pic is taken kneeling in the aisle under the duck under...which is why there is padding on the L-girder. The padding on the lower fascia is where I crawl under one of the helix L-girders to get inside the helix. The aisle here is about 3 feet wide and the duck under is about 4 feet long. The duck under shelf carries tracks at 61.5, 63, and 64 inches from behind me onto the peninsula to the left in front of me at 64 inches, and to the right front onto the top loop of the helix at 65 inches. FYI, the helix radius at the bottom is 15.75 inches and the top loop has a diameter of about 52 inches. Except for a portion of a 2-foot long segment about 1/2 loop from the top of the helix, all 7.5 loops of the helix plus a 3 foot long tangent one direction and three 2 foot long tangents in the other direction, were cut in one long spiral cut from one 4x8 ft sheet made of 1/2 inch OSB panel and 1/2 inch Homasote screwed together. The four legs supporting the helix form a 53x57 inch box with 53" L-girders and 57 inch stringers supporting the base and the stepped loop supports. (There is a 21x24 inch roughly oval-shaped hole in the base, that is off-center to one side to provide a wide lip for holding tools and materials while working inside the helix.) I also added a place to plug in my throttle when trouble-shooting inside the helix...rarely needed it, but it was wonderful to have for those rare incidents when the radio throttles were acting up. Changing the width of the helix ramp part way up the helix is possible...assuming the minimum radius already considers gaining sufficient clearance for the second loop to pass over where the first loop enters the bottom of the helix, I'm not sure about any advantage to a wider ramp at the bottom of the helix.
Boxing Day Update. | | (click to embiggen) Pulled out the double stack TTX once again to measure the height. 50mm to clear the ruler reliably; so that will be my short distances pinch. Track Plan revision 08 suggests a spiral helix will be 1330mm x 1030mm, give or take, so I clamped some timber in place and practiced walking around it all. | | (click to embiggen) This plan is much better for crawl-under height, although I will still pad the floor and the underside! Updated track plan on the planning thread I have the next two weeks off work, so hopefully I can start cutting shapes out of plywood soon
In addition to floor and underside padding, at 67 years old, I've found that it helps to have a leg or shelf at about 30 inches to grab onto or push up from when crawling or duck walking into my bowl-shaped helixes (underside of most of the helix support L-girders is about 42 inches from floor). If you run any layout wires near where you are ducking in and out of the helix, carefully secure them out of the way, because it is likely that you will eventually snag them, no matter how carefully you enter. I mentioned designing a wide lip for holding tools or materials when working inside the helix, but I've also found it helpful to keep a toolbox tray or wheeled cart near where I duck into each of the helixes, located so I can reach it from both inside and outside of the helix. That way, I only have to crawl back in or out of the helix to retrieve a tool that was last used inside (or outside) of the helix when I forget to put it on the tray or cart before leaving/entering the helix. I have a stationary decoder panel suspended under the Peoria helix, located so I can work comfortably on the front of the panel while sitting on a stool in the aisle. The back of the panel is accessed from inside the helix, and because the base of this helix is covered with a fabric skirt, the back of the panel inside of the helix is poorly lit, shadowed. Inside (and under) the helix, I clamped a small reading light so it shines from over my shoulder (instead of into my eyes) to illuminate the back of the panel. I wish I had planned the original wiring with enough forethought to have left myself more slack in the wiring and allowed the panel to swing on a hinge so the back of the panel could also be accessed from the aisle instead of only from inside the helix.
I looked at premade "boards with wheels" today, $60 will probably get me one that will do what I want, 160kg load limit, 4 wheel steering, 0 brake horsepower... Not sure I actually want 4 wheel swivel, it is useful for manoeuvring, but it is less likely to go where I intend when pushed. I bought more clamps instead. Always need more clamps Started the framing for the staging deck and helix. The square hole is 860x600 (34" x24") and I can nibble the long side for a tool shelf and the like. Obviously the curvy helix ramps will nibble the access hole down too
Okay, I appear to have missed an update, sorry 31 December 2016 Framing for the staging deck and helix base is up. I went with open grid not L-girder because I doubt I save much timber here. 20cm (8") spacing is not quite enough for the power tools, so it has to be assembled in order. Will have to remember that when I next move in a decade or so... | | | (click to embiggen) The design is anchored to the wall and to the layout legs, it is pretty permanent. On the outside edge, it will take my weight (8g x2.5" screws x3 into each wall stud, 8g x2.25" screws x2 into the table legs). On the inside edge, it needs another leg, or it will flex. The last picture with a stick of wood leaning against the framing shows about where the leg will go. Off to the beach for a week with the whanau (family)
6 January 2017 - Happy new year Back to the layout room The under-layout shelves are built as three boxes and held together with little metal brackets, which can be dismantled from outside / underside the shelves. I have now pinned the L-girders together using timber, again accessible from outside / underside the layout. This way things shouldn't move around under the trains. I also had an.. accident.. while moving the whole layout 2" to help the helix clear the table legs, one L-girder delaminated. So, I pulled out both quick-clamps and screw-clamps this time. Those L-girders have also been trimmed to length now. So most of the layout framing is done, except for the staging yard itself.
So, my intention is to use 12mm ply for subroadbed, being flexible to bend to a gradient, while being stiff enough to span a ways between supports. Add 3mm of cork and I have 15mm from track to framing. I also have 7mm ply which I was going to laminate to 14mm for a stacked helix. Maybe I will still use it for the spiral helix? But I also figure two sheets of 7mm is nearly 15mm, so I can use it to build my sector plate approach track. Sector Plate Approach Track? | | | (click to embiggen) Here is a mock-up in cardboard of what I am figuring to use to eliminate the staging yard ladder. This example is a 40cm radius (16"). It's back-to front, so the helix is off to the left and staging to the right. The staging tracks radiate out from the right side, just like they would meet up with a turntable, and will probably be soldered to copper pcb here to provide solid registration. The sector plate is then pivoted to line up with one staging track, and ideally only that track is powered with the rest being isolated. The right (pointy) end of the wedge has the flextrack held tight - probably soldered to copper plate, and must also have some positive alignment scheme - probably a small metal latching bolt (because metal conducts to enliven the aligned track). N-scale is pretty picky on it's alignment so the registration has to be pretty well exact The left end of the track is also pinned somewhere 4-8" past the pivot point. The resulting flextrack is not pinned in the middle, and as shown above, curves wonderfully as the sector plate is swung. So the point of a solid sheet of ply under it is to stop trips to floorsville The two ply sheets will be lacquered and generally worked over to reduce binding and provide a free and easy swing. I don't think I have enough vertical space for a more positive system (curved rack and pinion, Z-scale bogey and track, etc). Next, the free rail changes length around the curve. With Atlas C55, I measured about 12mm (0.5") change from full left to full right on the one rail that moves. I did find on the internet somewhere someone has done this before, and he used a construct of rail joiners very artfully soldered to the stationary track, together with filing the sliding track to a "blade", so wheels are supported vertically and horizontally across the join, no matter the angle of the curve. Peco flex track has both rails sliding, which would simplify the join point (make both rails slide 6mm instead of one rail slide 12mm); but Peco track "holds" it's curve and would not be happy in this application I think. Which is a pity, because I have surplus Peco C80 and was thinking of making the staging deck / helix using it, and save the C55 for the visible layout The movable plate doesn't have to look like a Star Destroyer, here is a second mock-up with a 30cm radius (12") (pivot pin marked by the grey square), including a stack/well car to check the resulting curve is actually usable. This design shows the rail "kinks" if it is pinned too close to the pivot; while the 16" design up there actually does a "reverse kink" if it is pinned too far past the pivot. Conclusions So, from this mock-up I can see that the design itself is probably plausible, and there will be a few issues to overcome; Precisely accurate alignment of staging tracks freely sliding parts - sector plate on deck and track on sector plate rail length change accommodation minimising timber waste
Playing on google with search terms like "sector plate" lead me to model-railroad-hobbyist.com, where it shows quite nicely the half-lap sliding joint and some useful photos. I suspect I have wandered past this page before. That site also suggests the naming of things all staging tracks on a long board that pivots to line one train up with a single entry, like a giant turntable with 5-7 tracks on the bridge, is a "sector plate", very popular in England all staging tracks are fixed in place and the approach track pivots to line up with one of them, like a 5-7 way stub switch, is a "selector track". That site credits Ken Rickman with designing a Selector Track and Dustin Whitten with building it! And also, apparently Rick Spano had not one but two Selector Tracks on his "hyde yard" run automatically under Computer Control, way back in the early eighties. His website at scenicedandundecided.net has a text description but no pictures alas. My browser says I have been there before today, too Back to my layout. I played with building a Sector Plate proper, which might be easier to construct; it would take the form of a slice of pizza, 2m long (6'8"), 150mm (6") wide at the point and 300-400mm (12-16") wide at the crust. It could bulge out on the aisle side, but the wall side has a pretty hard limit on the swing - the wall! In all a sector plate instead would be possibly easier to build, but will mean that for most of the length the space between tracks is compromised, making this a storage area, not a finger-fiddle yard. I also made more cardboard mockups of 16", 12" and 8" (40cm, 30cm, 20cm) swinging parts and found that with Atlas C55 track, the unfixed section pretty well has to be a half metre long (from track end to first fixed point on the helix approach track). The amount of length change increases as the pivot length decreases, and the curve gets tighter, about 16" radius on a 12" pivot, and tighter on 8". Unfortunately I then rechecked my assumptions about space. Fixing the track right at the turnout at the bottom of the helix will get me about 6' of staging yard (longer than any main-deck siding) which I like. But it puts the pivot point of a 16" pivot right under the helix support! So I need to rethink things, and probably move the moving parts away from the helix footprint, accepting a 5' staging yard (just longer than any main-deck siding). I also want to test Peco C80 flextrack. But that requires me to find my pin vice... I wonder if the building of a sector plate / selector track would garner enough interest to spawn a new thread?
That slipping rail joiner is a clever solution! How do you plan to align the moving selector plate to the fixed individual staging tracks? Obviously, a bolt attached to the selector plate worked well for them. But if you are a little more ambitious, and/or want to disguise the aligning method/mechanism or bring your scenery closer to or even into the staging track area, I think it would be possible to run a long, threaded rod horizontally under the selector plate, and turn it by a sturdy motor mounted under the deck or by using a hand crank from your fascia. To accommodate the subtle change in angle as the selector plate arcs around the selector plate pivot, it would be necessary to attach the rod to the selector plate through a slot rather than a hole if the rod rotates around its axis but the end points of the rod don't move; or, if the rod is attached to the selector plate thru a hole (rather than slot), the far end of the rod will have to be able to pivot around the motor or crank end of the rod. Turning the rod one direction would move the selector plate toward the wall and the other direction, away from the wall. The gearing of the motor or the size of the crank will determine how precisely you will be able to align the selector plate to each of the staging tracks.
Hello. At present I was thinking of making things manual, as there can only be one train on the helix it will be the job of whoever is steering that loco to see it home (either the mainline runner, or they hand off to the staging yard operator at helix top). Given the placement in the shadow of the helix, there's not much call for scenery down here If I did automate it, I know a few people fond of robotics and arduino, so I have a few ideas Simplest is a worm and pinion on the pivot. Or a threaded rod like a screw-jack. Or a stepper motor / servo with linkages and hopefully not too much slop. And there are other approaches. All require some form of feedback to know they have picked the right track - the most geek solution is an overhead camera and some image recognition software. More realistic are micro-switches, opt-interruptors, tiny magnets and sensors, mirrors and lasers, ... Positive alignment is going to be very important for N-scale. One of my frustrations on previous layouts is the ease with which N-scale derails on moving joints. I will definitely build the alignment system first, most likely some combination of springs and bolts, and then lay the track second! The staging deck: The metal bar on the left is standing in for the staging yard itself, 12-14" wide and holding 5-7 tracks spaced to let Mk1 fingers in to fix issues. The flex track on the right is the approach line from the helix, which terminates in a pair of Wye points about 12-20" past the edge of the framing timber shown. The upstanding bits of wood are about where helix supports will go. Obviously either the track or the support will be notched to let trains past And the whole thing gets another 1/2" of plywood subroadbed yet. This shows me that I need about 16" of S-bend length to get from 7-tracks in 6" width to 12". (there is no point going narrower than half of the staging yard width, because the approach track is fixed at this mid-point anyway). 16" of length leaves me with about 5.5' of staging yard that is well spaced, which is probably adequate. And having the staging yard that wide doesn't actually protrude into the aisle too much either - mostly because the helix framing is right there narrowing the aisle already. So, it may be possible to build a Sector Plate instead of a Selector track. Pros: probably simpler construction, it's been done before more often, it can be made a separate unit that can be removed for repairs, it's clear of the helix supports Cons: it requires getting 6-7' of timber to pivot smoothly (heavier, larger contact area), it moves with 5-7 trains on it, fine alignment may be harder because of weight and unwieldiness The alternative I started with is a Selector Track, where the staging yard on the metal bar remains fixed and the approach track from the right flexes instead. Experiments with Peco C80 rail show that it might work even better than Atlas C55, despite the Peco not "springing back" to straight as readily as the Atlas; it seems to make a smooth curve readily enough for me. Further experiments have seen that 8", 12", 16" from tip to pivot, with the last 2-4" pinned at the tip, all require the flextrack to be pinned about 20" beyond the tip, or it kinks and starts misbehaving. So 8" of pivot arm + 12" of curve easement, or 12" of pivot arm + 8" of curve easement, or 16" of pivot arm + 4" of easement. The shorter the pivot arm, the tighter the curve and the more the rail length changes. Given this, I definitely prefer the 16" design. No matter the length, either the pivot point ends up under the helix support and the staging yard + helix framing are permanently attached, or the staging yard is only 5' long, the pivot point is on the staging yard framing, and the staging yard is removable for repairs like with the Sector Plate design. Pros: more technically impressive no trains move, fine alignment will be easier because it is smaller Cons: sliding rails require more technical effort (but I do own a soldering iron), either a shorter yard than the Sector Plate (removable for maintenance), or the pivot point is under that helix support (entire staging deck fixed together) Anyway, I decided to leave that one to mull over some more and taped together about 16 square feet of newsprint and drew the reverted loop onto it at 1:1 scale. Sorry pencil on newsprint doesn't photograph well. I will probably retrace in ink for clearer pictures. This shows that, assuming I got the table legs in the right place, it should be possible to build the reverted loop on the staging deck and clear the helix and everything. So I can touch up and tweak the plan a little and then transfer it to the plywood subroadbed. My approach there will be to make little jigsaw pieces to save plywood and fit them together on the framing nice and tidy-like. Although, a solid helix-base might make a good place to leave tools lying around
I fossicked in my boxes from moving and found my NMRA gage <sic> and my 150W 15VAC power supply, so I can actually power my DCC command station But I didn't find my loctite, which would make the compass more fun and more reliable. So I have retraced the reverted loop 1:1 with ink, and added shoulders. I am figuring 6 cm (1.2") of subroadbed (3cm each side of centre) is probably enough to stop errant engines taking the four-foot trip to floorsville. Next I cut it up like a jigsaw puzzle (guess which tool I will use on the plywood version? ) and fitted the pieces to the framing: (as always, click to embiggen) From the "north" aisle looking across the helix at the staging yard. Little bits of timber indicate helix supports and weigh the paper down. No tool shelf on this side, the paper ends where the framing does. Looking down from the main yard. Bottom left is the leg the #2.5 wye point will clear, just. Looking across from the central aisle. Little exclamation point is to remind me that this helix support has not much under it. I may add a stiffening bar under the subroadbed to stop things wobbling. Notch on the top left is where the staging yard meets the approach track, be it sector plate or selector track. From that notch to the end of the staging yard is 2.2m, 86.5". Take 0.5m off for the Selector Track or the S-curve from the Sector Plate and I've got 5.5' of usable, parallel, finger-friendly staging yard. Looking down from the staging yard. Tool shelf is front and centre, with a little note that the access hole could be 2" smaller and still work. So there we go. From here, I can try pinning the paper to something stiffer, like cardboard, and triple-check all the critical dimensions - make sure things clear the layout legs and do cross the framing in enough places to be screwed down (look closely, many of the paper joins are zig-zagged over framing). Then I can take the paper pieces and trace them onto my 1/2" plywood sheet, trying to minimise waste. Then the plywood jigsaw pieces can be finagled into place. Probably after a few hours spent with Mister Rasp.
Life is intruding on hobby times, I have taken more photos, just need to upload them. So, I did cut out the paper 1:1 template and fit it into the space; making changes as I went. It is definitely easier to edit paper than plywood, especially to make things bigger! The pieces were sawn out, rubbed with a rasp, made to fit and screwed in place. Also started cutting the box framing for the main staging yard. The "selector track" (short pivot section) approach has won, and I think I can get an acceptable body track length, while keeping the Gubbins away from the helix, and even making the whole thing removable for repairs. From here, I guess I can transfer the track centre lines to the plywood and start working on the track and wiring.
(click to embiggen) Staging yard framing in place, the hole in the deck is where the selector track mechanisms will go. I have learned that the summer sun heats the train room beyond a comfortable temperature, so I have been knocking off early and hiding in the pool with a cool drink. But still, I managed to buy some steel rod and trim it to length; I now have a compass for my plunge router. (click to embiggen) The little wood block is screwed to the middle of the curve, and the metal rods adjusted by friction to the right length. One improvement it needs are set-screws on the wooden block, to hold the radius more precisely. This jig still requires the curve has a centre - which the track around the helix doesn't. (click to embiggen) With the router jig I made a curved stencil, with tangent track on one end and 400mm radius on the outside (about 16") and 360mm radius on the inside (about 14.5"). Stencil can be used on any curve on any surface, and flipped over to be used on any other curve. Using my new stencil, I made halfway-accurate markings for the centre lines of the tracks on the staging deck. The pencil does not photograph well, but it does let me erase the mistakes! If I want to use cork, I can lay it around the curve and glue and spike it. If I skip the cork, I can lay flextrack around the curve directly. Still not sure if I want to cork the staging deck or not. It has little scenic value, being dominated by the helix supports!
Am thoroughly enjoying your updates and progress. That slip joint idea may come in handy for the longer straight sections of your layout, due to the heat in the summer and cooler winter weather there. My Railroad room swings about 25 degrees F during the year and I have found it needful to build in lots of expansion gaps with the code 55 rail.
Flex track tends to get soldered around curves and left with 1-2mm (1/32"?) gaps for expansion - don't solder the joiner at all, and it can slide around as needed. Cleaner/easier than a full half-lap joint, and makes a click-clack sound for the trains I think I will put cork on the staging deck and helix. It will require that I find more cork, I estimate I have 50m of the stuff and the computer estimates the track plan is 85m On with the staging yard and Selector Track! Experimenting with track spacing and Mk.1 fingers, I can just get my head under the shelf above to fix any derailments with tracks 30mm (1+3/16") apart, I can just get my fingers in and fix derailments without derailing neighbouring cars with tracks 40mm (1+9/16") apart, I can easily remedy derailments and not disturb neighbouring tracks 360mm / 40mm = 8 tracks with 1.5" at the front of the yard. So I have gone asymmetrical, with the closer 5 tracks 30mm apart and the further 4 tracks 40mm apart. So I can see that I can curve 9 tracks in to the selector approach track thingie, and they will space out 3/4"-1" on the arc. | | (click to embiggen) So, I think my technique here will be, first, a sheet of plywood is currently gluing to the underside of the "keyhole", held together with clamps and packets of lead shot (from my misspent youth). Today I will pull that apart and carry on. I have found some brass stock and a bolt that pivots cleanly in it, so I will glue the stock in the keyhole at the pivot point, and then the selector track triangle itself will fit nicely in the keyhole. More brass stock will make a sliding latch and fit on the little "landing" at the point of the selector track. Both the fixed arc and the moving point will get some PCB glued down, which the approach tracks will solder to as will the alignment bolt - alignment bolt first, then tracks. I am learning If I have cork on the staging deck and yard proper, I might skip cork on this mechanism, and use that extra height for some washers and friction-reducing attempts. So, in operation, the yard master ensures all the moving parts are clear to the colliding points; then he/she slides the bolt and frees the selector, moves it to the desired track (probably by pushing or pulling on the bolt, humans are lazy), and slides the bolt home to maintain alignment. No fuss, no muss. The bolt being metal-on-metal and soldered at both ends, it might even be practical to use it to power only the lined up track. Bonus
