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


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.


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.


Track Power Regularized


Comstock Road’s DCC bus in now powered in a proper way instead of the temporary hookup where I just connected command station to the traverser leads. The only track connected is the traverser and the two traverser lead segments on the same module but this means that I can run the loco on and off of the traverser. Operation!

More importantly, the command station and power supply are located at the far end of the layout and plugged into a dedicated outlet. When finishing the layout room in anticipation of the previous empire, I went all in and wired up the six circuits represented by the switches above. The intended uses were, in addition to room lights and general outlets, four outlets grouped at the end of the room for separate control of layout related circuits. Track, accessory, lighting and something else I don’t remember. It is a small thing but actually having the intended track power hooked up to actual track feels like an achievement.

Proper labelling TBD.

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.


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.

Going with a Lead Screw

leadscrewdelivered.jpgAfter much pondering (variations on that phrase get used a lot around here), I have decided to go with the simplest (relatively) solution for propelling the traverser, a single lead screw. It was always one of the options and after chatting with Trevor Marshall and Ryan Mendell at lunch, it was decided. Ryan deals professionally with assorted ad hoc projects and he tells me that lots of people try belt drives and fail to consider the tension required to get them to work properly. Since I have no desire to see if the traverser baseboard will bend under sustained tension, lead screws are the best alternative.

I conflate ball screw with lead screw in my thinking but I understand a lead screw is better for my applications since there is not requirement to handle heavy loads or avoid backlash of a couple of thousandths of an inch. My concern with this option was that aligning the screw, table and baseboard would be tricky and prone to binding. Ryan suggested attaching the nut (brass bit in the picture) so that it floats a bit. I thought about it and I have a plan to do that.

So, the alternatives considered:

  • single lead screw
  • single belt drive: two pulleys doing the same job as the lead screw but avoiding fine alignment challenges
  • two sychronized steppers with two lead screws or two belts attached to each end of the table.
  • one belt attached to each end of the table belts driven by pulleys mounted on a common shaft attached to a single stepper.
  • one belt routed so that it was attached at each end of the table. This is a simplified version of how printers are designed.

As you can see, I have been looking at all kinds of fun approaches. I still like the single last one but, besides the tensioning challenge, it represents a substantial increase in required hardware with an estimated 5 idler pulleys in addition to the driver pulley as well as roughly 8 feet of belt. None of that is especially expensive on a per unit basis but the total adds up. At that point, I am would be investing in additional entertainment value.

I ordered an 8mm lead screw, nut, flexible coupler and bearing combo of the required length (sadly not available locally as far as I could discover) and it arrived yesterday. Actual installation work will wait on vacation and the right mood.