Diamond Ho!

This weekend I kept up the momentum created by getting the first turnout servo installed and started in on the only bit of Comstock Road’s trackwork that requires hand made frogs, the diamond crossing. Through the miracle of Templot, the diamond is asymmetrical with one leg being on a transition curve. Not something you are going to get off the shelf but a feature that let me squeeze things in the way I wanted. Now I just have to build it.

I started by re-reading the relevant sections of Trackwork Handbook for Model Railroaders by Paul Mallery since I have never built a diamond and haven’t built a turnout frog a very long time and not many of them then. Including the diamond in the trackplan was a deliberate creation of an opportunity to do something a bit challenging.

I printed off a copy of the crossing template, found a suitable bit of pine 1×4 and my file and dove in. Much bending, filing and fitting later, I was ready to apply some solder.firstfrog.jpg

Once I figured out that my piddling little 80W digital iron wasn’t going to cut it, I broke out the big 120W Weller and things started flowing. I soldered things into a blob and then spent more time than I like cleaning it up. Nevertheless, a result was achieved that compared well with the paper version.templatevsreality.jpg

The second frog aka V-crossing went considerably faster as I applied my learning from the first one. It was necessary to redraw the reference lines before I started since the wood block got a little singed.secondfrog.jpg

At the end of the evening, I have both V-crossings built and am looking forward to doing the K-crossings. I have not applied any detailing to the frogs and may not do so prior to installation. I will probably regret this decision. Here are both pieces posed in situ on the layout.vcrossings.jpg


Weekend Reading: Trackwork Handbook for Model Railroaders by Paul Mallery


This the book I was re-reading this weekend to brush up before starting in on the diamond crossing for Comstock Road. I have had this book for many years and actually did a search of my previous postings because it seemed strange that I had not already done a post on this book.

This classic is THE book for those intending to hand lay model railroad track in the North American tradition. It covers all kinds of details of the prototype and then gets down to practical advice for the modeller. Written long before DCC or the advent of the Fast Tracks CNC made jig empire, the methods described are what you need to build any kind of track using flat bottomed rail, spikes and a few simple tools. I needed to re-read parts of it because I haven’t built a turnout frog from scratch in more years than I care to count but the asymmetrical diamond on Comstock Road is just the sort of situation where these methods shine.

Even if you do everything with commercial jigs or castings, I highly recommend this book as a reference for prototype practice and other practical trackwork matters. Published by Carstens, it is currently out of print and not listed on the White River Productions site although several other Carstens books are. It looks like the book stand at train shows is your best bet if you want a copy although you might turn up a reasonably priced copy online. (unlike the unreasonably priced ones I found when I checked while writing this post.)

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!

A Bit More Turnout Control Progress


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.


Beginner Brass Bodging

I have previously mentioned some books on model related metal work by Simon Bolton and Kenneth C. Foran. My soldering and brass shaping skills are rudimentary at best and I did not feel comfortable plunging directly into rolling stock construction so I set out to find a simpler project. While walking past a construction site, I hit upon the answer, a roll off waste bin. These ubiquitous items of the modern era are locally sourced and constructed from metal sheet and structural shapes. Just like those in the metal rack at the hobby shop!

I cast about for a suitable example and discovered that most waste disposal companies provide overall dimensions for their bins as well as photos thereof. Just the thing for the modeler in need. Subject identified, I prepared a basic dimensioned drawing and set about acquiring the necessary brass square tube sizes and sheets.

I made good progress but there was an issue. My Hakko FX888 digital soldering iron is not quite up to the job of soldering a joint where one or both halves is a big sheet of brass aka a heat sink. Cold joints were the order of the day and I put things aside while I mail ordered a big 120 watt iron in hopes of solving that problem.

Today I dusted things off and had a go, big iron and all. The thing is a monster with a half inch tip on it. Not for detail work but boy howdy, does it heat things up. Maybe too much. I managed to avoid desoldering everything previously attached but that wouldn’t be hard to do. Perhaps a finer tip is in order if I can get one.

Anyway, here are the two competing irons, the Hakkohakkoiron.jpg

And the 120 watt Weller old school iron (not so old school as to involve fire but still)bigiron

And here is the project to date. Todays progress was putting the sides, end and bottom together.binprogressjpg