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

Weekend Reading: Animated Scale Models Handbook

animatedscalemodels.jpgWhile I was in Kingston, ON on Saturday, I was able to take a bit of time to visit the Kingston Railfair train show. As is my habit, I browsed through the used books because one can never have too many books! I was lucky enough to come across Animated Scale Models Handbook by Adolph F. Frank. It was inexpensively priced so I took it into custody out of curiosity.

I am pleased to say that I am not disappointed in my latest acquisition. I have not finished reading it yet I soon will. Published in 1981, Animated Scale Models describes methods, materials and mechanism for animation predating the advent of inexpensive microcontrollers, stepper motors and servos. While some of what is described has been superceded, much of the wisdom of creating mechanisms from simple materials still looks useful.

Materials and tools described are only the ordinary sort that can be easily obtained. While the tool list certainly does not include a lather, I am also certainly going to find things to do with mine in this book. And save money either way. One can buy pulleys from a hobby robotics supplier, for instance, but the cost can add up in a hurry. Using the techniques in this book, one can readily build inexpensive alternatives that are exactly what is needed.

The book itself is soft bound and printed on non-glossy paper. It is well illustrated with plenty of clear drawings but despite the blurb on the back cover, no photographs other than the one on the cover. No pretty pictures here, just the stuff you actually need. Chapters include basic components, speed reduction mechanisms, mechanical movements,  and various example projects including a ferris wheel, a factory with a bicycle assembly line and more prosaic things like a small house with a man swinging a hammer to repair the roof and grandma rocking her rocking chair on the porch.

I think I can safely assert that any model railroader could find something useful in the Animated Scale Models Handbook. I look forward to employing some of these techniques to liven up Comstock Road. While apparently no longer in print, the online book retailers seem to have multiple used copies available at very attractive prices if you are interested.

Jeweler Saw Practice

Having just finished the electronic part of installing a DCC decoder in Comstock Road’s lone Atlas O SW-8, I set out to finish the job by making sure everything was correctly insulated, taped down and able to fit inside the diecast metal shell. Perceptive readers might wonder why I mention the shell material. That is part of the fun!

Getting the wires all tucked in was not too much of a challenge but I then discovered that my estimation of clearance between speaker top and shell was, er, optimistic. The issue was the speaker mounting lugs cast into the inside of the shell. They are almost a fit for the chosen TCS speaker but only almost. I have also elected to not attach the speaker to the shell to give more clearance for a future detailed grill.

Here is what the inside looked like when I started.sw8mountlugs

Since the lugs had to go anyway, I resolved to “daylight” the opening back to something akin to the prototype rectangle. This would give plenty of room for the speaker to shoot upwards.

I got out my trusty jeweler’s saw and my excessive supply of #0 blades. Back in the day, I bought a gross of this blade size in a fit of enthusiasm and only afterwards discovered that #0 is too coarse for .015″ material. I have despaired of every finding a use for all those blades but no longer!

Even the relatively heavy #0 blades are fragile and do not tolerate careless use. You can turn corners in a cut but you have to carefully saw in place while rotating cautiously. If you push to hard you can jam the blade and snap it. Letting the work twist on the blade while repositioning can break a blade… You get the idea. Fortunately, I have about 12 dozen blades for just such an emergency. Or I did. I am now better at sawing and have less blades.expendovblades

Eventually, I got the opening cut out to my satisfaction. Here is the view from above with the shell on. (Apologies for the bad focus.)speakerhole

And here is the top view with the stock screens and grills back in place. All being black, the speaker is not visible unless you get up close and look straight.sw8postsurgery

DCC Install Complete-ish

Here is the full installation less wire tidying and any lighting connections. I don’t plan to hook up any of the lights because stripping the shell is in the near future so I don’t see the point.

This shot is very similar to the previous post except for the addition of the TCS speaker and LokSound PowerPack. Getting those soldered on was not any more difficult than the basic motor and pickup connections but my haste and ignorance did result in a bit of comedy.

AtlasODCCInstall

Firstly, I have hooked up the ESU CabControl system but I haven’t read anything but the Quick Start card nor have I operated with the system elsewhere often enough to know it. I can just about remember that the first three function keys are light, bell and horn. So, first heart stopping moment was when I applied track power after hooking up the speaker and got… nothing, nichts, nada. (no smoke, either). But then I tested the controls and the loco moved so no fried decoder. Eventually, I figured out that I have to F8 to “start” the loco and the room filled with the glorious sound of a 567 winding up. After noodling back and forth enjoying the sound, I was off to apply the keep alive capacitor.

The connections for the keep alive are on the side of the bottom board so I removed the decoder proper to get clear access to the relevant pads. Soldering the three connections was easy and I excitedly put the loco back on the track for the big test of the full system. And nothing at all. Not even movement. A bit of checking of documentation (does it need to charge or something?), connections (did I short something this late in the game?) and head scratching later I realized that I had a very good view of the soldered connections. Almost like the decoder wasn’t blocking the view. After plugging the decoder back into the board, all was well and the family was summoned for the big demonstration run.

I then did a bit of switching of my test tank car back and forth between two approach tracks and the traverser. I now have strong motivation to get the wiring sorted so more extensive running can be done. And also so I can move the DCC base unit off of its precarious perch on top of the layout.

In at the DCC Deep End

My big recent hobby related purchase was a DCC system. Since the incumbent control solution is an MRC Tech II 2500, moving to an ESU CabControl system skips about 30 years of progress. With the cart firmly in front of the horse, I set off to develop a decoder solution for Comstock Road’s singular non-DCC ready Atlas O SW-8. Which will also be my very first decoder installation.

After some research, I elected to keep giving ESU Loksound my business and went with the following:

  • LokSound L Select decoder (with recently available EMD 567CR sound file for correct 8-cylinder 567 sound!)
  • TSU large oval speaker that almost exactly fits the opening under the top grill.
  • LokSound PowerPack Maxi

One of the big advantages of standard gauge O scale is that there is buckets of room inside a diesel shell for you to put a decoder. No milling frames or faffing about trying to isolate the motor from the frame.

After playing hide and seek to figure out where I hid my sheet of .040″ styrene, I was off. Credit for the general approach goes to a post by “Bob, Curator of the A&O Historical Society” on the O Gauge Railroading forum.

Over the course of Sunday, I got the loco apart, the platform made, platform and decoder fixed in place and the leads for the track pickups and motor soldered. This is the minimum to actually run the loco so of course, I did.

Not pretty but there was a soothing lack of magic smoke containment failure and the DCC age dawned on Comstock Road as the shell-less chassis trundled back and forth on a traverser track. Sound, electrical resilience and wire management pending.

MarksFirstDecoder