Turnout Control Conclusion

If you have been following along, you know that I have been attempting to devise a way to throw Comstock Road’s turnout points using a servo and a rotary motion mimicking a manual switch stand. The initial attempt using the mounting scheme appropriate to the typical back and forth scheme was not a success. After much scheming, I became resigned to having to mount the servo face towards the baseboard bottom and with shaft in line with the vertical throw shaft.

Happily, I came across a similar scheme used and well documented by the Delmarva Model Railroad Club that I could adapt to meet my goal. Rather than use a couple of blocks of wood, I used a couple of pieces of aquarium bubbler hose and 1 1/2″ #6 wood screws.

Before I tipped the center section up to get at the servo location, I taped down the points, throw bar and all. This kept things centered as well as prevented the pins holding the throw bar from falling out. Family lore includes the time we tilted a sofa bed while lugging it up the stairs and it went sproing. All subsequent movements start with tying those suckers shut! Note that digital photography has not stopped me from exercising my talent for getting a finger into the shot…boughtthatfarm

Things secured and disconnected, I tipped up the section, clamped it in place and re-bent the vertical wire to the new spec. The horizontal leg has to match the distance between the servo shaft center and the last hole on the servo horn.turnoutwiremk2

I plotted out the mounting holes to put the servo horn perpendicular to axis of the servo mount at center. This turned out to work but only just. The servo shaft is not centered in the housing so the near mounting screw interferes much sooner than the far one. The interference issue is only relevant when you invert the servo like this. Future installation will offset the center point to split the difference in the available travel.servobracketmk2

I tried to capture the situation when the turnout is thrown to that side. The servo horn is right up against the tubing but the turnout is thrown so we will call that a win.servohardover

Finally, I am awaiting the arrival of appropriate bits and bobs to wire the servos, controllers and driver board permanently. I can still operate one turnout at a time at close range via temporary measures. Also note that I forgot to install the frog polarity relay while I was “under’ the layout. One more for the checklist.verytemporary

I did a run of the test train to prove things worked so I can now claim to have an operating layout. I can now perform an Inglenook scheme via this turnout, the back track and manually pushing the traverser. Or at least I could if I had enough cars converted to P:48. I will need to do an inventory and get that under way.

Getting one turnout is not a huge deal but getting a working method sorted out to my satisfaction is a mental obstacle overcome. Onward!

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A Bit More Turnout Control Progress

tamvalleyallin

Pictured above are in order, an Octopus III servo controller, remote relay, fascia controller and micro-servo, all from Tam Valley Depot. I bought a bunch of each for the previous layout and never did get any of it deployed so I am both pleased to be finally using it all and having to learn how to do that.

Tonight I soldered up a fascia controller kit (two LED’s, a button and a connector) and messed around with the remote alignment board to get the hang of it. I think I can do it all now including, ahem, factory reset the Octopus in case I mess it up. Hypothetically speaking. 🙂

Next concern is that the required throw for the points is about 100 degrees of rotation. To get that out of the servo will require it to be quite close to the point of rotation which creates other alignment issues. I am having a bit of a ponder about what to do about that. I will also tip the board up for the next bit of fiddling since I can’t get under the bracket location with a screwdriver due to the sub-baseboard. Hopefully the assorted point bits won’t fall off since I haven’t permanently attached any of it.

Turnout Control Progress

I have mentioned previously that getting hand laid points connected up and suitably under control has been a stumbling block in past efforts. The achievable scope of Comstock Road (4 or 5 turnouts total) makes the mental size of the task easier to contemplate. I have begun the new year as I mean to go on, by tackling the mentally hard things and have made further progress.

First up is the connecting rod from switch stand location to throw bar. Increasingly prototypical possibilities have occupied my imagination but when I found myself contemplating scratchbuilding scale clevis’, I realized that I was making things harder than they should be, certainly for a first attempt. I resolved to make something out of the piano wire on hand.

I needed an eye or loop in the wire to connect to the vertical shaft comping up from beneath the layout. (I am going for a rotational motion like a switch stand rather than the model railroady back and forth in a big hole. I fashioned a simple jig consisting of a piece of scrap plywood with a nail driven in and cut off, and adjacent to a piano wire sized hole. A right angle bend near the end of the wire goes into the hole and the wire is wrapped around the nail to form the eye. I got the idea for this jig from the Animated Scale Models Handbook.

Here is the jig.bentwirejig

And here is the result trimmed up.eyeinwire

I have got the vertical brass tube and wire combo installed and connected to the throwbar. (We pause while I dash downstairs to take a photo of the installation which I apparently forgot to do. Lack of photos is usually a good sign since it indicates that I have got a head of steam up.) Here is a shot of the connecting rod installation. Bending the crank in the end of the vertical wire was a challenge and I will consider better alternatives such as soldering on a separate piece of brass bar. It does work and will be concealed by the switch stand. The other reason for a separate bar would be to allow the vertical wire to continue up through the stand so the target can rotate.connectingrod.jpg

Finally, we get to installing the servo, Tam Valley Octopus servo driver and associated electrical bits. I have got as far as fashioning a bracket for the servo using a section of 1/2″ aluminum channel from the big box store. I picked this idea up somewhere in the model railway reaches of the internet and it works a treat. The servo is just a friction fit in the channel after a slight pinch with a pair of pliers.bracketmk1

Finally, A Throwbar

As I may have previously mentioned, actually hooking up turnout points is one of the mental hurdles in my path to layoutdom (layoutness?). Today’s project was getting started on hooking up the points for high track with a throwbar. The method of pinning the two together was the challenge. Learning took place.

I had a plan that involved using very small hex bolts 1/8″ 00-90 that did not survive contact with reality. The clearance hole for the bolts is a drill number in the 60’s that turned out to be too big a hole to reliably drill in the tabs of the American Switch & Signal (now sold by Right O’Way) points. I managed one and then the next tore out. Break time!

For the second attempt, I went with an idea I vaguely recall from somewhere, cut down straight pins. The standard steel sewing pins almost fit through holes as-is so they work much better. They are easy to make which is fortunate since they also fly very far if your grip with the tweezers slips.

After assorted bits of filing, drilling and fiddling, the test fit was completed. I expect the installation of the rest of the throwbars to go much smoother.

firstthrowbar

Putting a Stop to It

Now that I can run the loco on Comstock Road, there now exists the possibility of rolling stock taking inadvertent flying lessons. This is much to be avoided so after one scare involving a combination of touch screen finger trouble and momentum effects I knew I need to take steps. It is a small job but it is now a small job done. I cut up some scrap pieces of 1/4″ plywood and made stoppers for the four ends of track. They are fastened to the subroadbed with wood screws which should stop the loco unless it really gets up a head of steam.

The end on shot is an artifact of having to detach the section to get at the ends which normally are about 6″ from the wall. I am pleased to have this taken care of until I get scenery and/or backdrop ends installed.

tempstops

Comstock Road at One Year

It has been approximately a year since I finalized a trackplan and started construction of Comstock Road. As one does, I took stock of how things had gone.

Current state is still mostly bare trackage abuilding but what trackage there is is considerably more functional that it was before. Here is how I see the state of things

  • Steady albeit slow progress still going on. This is the main achievement. I am still interested and still getting down to the shop to continue the project.
  • Just this afternoon, I got the high track and main on the non-traverser end wired up and can now run a train from one end to the other. And did!
  • First DCC sound install completed and DCC system wired up.
  • Still haven’t got a turnout servo installed although two turnouts are essentially complete. This is obviously my next psychological hurdle to clear.
  • The sectional design is holding up well, I can take them apart and put them back together with impunity. This includes wiring connections.

Goals for the near future include:

  • Get that first servo installed so I can start Inglenook style operating.
  • Basic foam ground forms in so I can stop worrying about derailments (which haven’t happened) causing a long drop to the concrete.
  • Traverser automation installed. Manual alignment from the front is challenging.

Here is the obligatory status shot. Not visible is the wiring and the 40 percent or so that of laid track that has tie plates spiked on all ties.

ComstockRoadOneYear

A Minor Triumph of Ergonomics

Inspired by my initial bit of wiring to get the loco off the traverser, I got stuck in on the wiring for the completed bits of trackage on the center section. Things are considerably more involved that two pieces of plain track so more time is needed. My lower back soon let me know that the awkward bending over I was doing was not appreciated. And then it hit me. When I regained consciousness, 🙂 I realized that the propped up section was at a perfect height to work on. If I was sitting down. A quick policing up of the floor in front of the layout (power cords, project box, …) later, I had my work bench chair in position and I was back on the job.

Here is the view from the chair.seatedwiring

I will do a separate post on my wiring methods, such as they are, but I wanted to touch on this particular advantage of sectional/modular/small layouts. The ability to tip up a section to get at the underside without crawling about on the floor is a definite advantage I had not really appreciated up till now. I have done enough crawling about under my own and others layouts that doing the same work seated upright seems so easy that it feels like cheating. And that is before we discuss the prospect of soldering wires while looking up: “The most important tool in the shop: Safety Glasses!” — Norm Abrams.

There are compromises that one has to make for a layout to be portable, some of which I would rather not, given a choice. It is nice to (re)discover an appreciation for one of the advantages.