Servos Wired

Over the last few days, I have worked my way along to completing the servo installations for Comstock Road. There was a bunch of other wiring tasks required that got done while I procrastinated on the servos themselves. When I actually got around to them, things went reasonably well although I did have to get out the multimeter at one point to debug what turned out to be an insufficiently inserted Anderson connector lug.

More or less in order, I did the following:

  • installed the board that holds the Octopus board and relays
  • connected the control panel to above. (OK, order did matter here)
  • ran wires from the relays to frog feeders
  • ran a servo cable from the controller to the runaround turnout which is the only servo not on the center baseboard section
  • applied Anderson Powerpole connectors to the runaround servo cable to span the gap between baseboards and jumper connectors to both ends
  • ran a cable and jumpered the other servo run which is not right next to the control board
  • bent up the link wires and installed them through 1/16th” brass tubes
  • actually installed the servos
  • tested everything, (multimeter comes in here)

The next step will be to make up the throw bars and link them up so I can align the servos and run some trains.

Here is the control board wired up. I used some small wire wraps to tidy things up a bit. Without the wraps, the y-cables connecting control panel, relay and controller made a bit of a rats nest.wiredcontrolboard.jpg

At the other end of the center section, I created a “cable” by wrapping all the wires going into the Anderson plugs with electrical tape. This makes it less likely that the smaller gauge wires will get damaged when the connection is made and unmade.wiringharness.jpg

Note that only the white and grey DCC bus wires look like they need these robust connectors. In fact, I had to solder the servo and frog wire to the lugs before crimping them since the crimp isn’t tight enough to grab the small gauge wires.

Octopus On A Plank

I have some task to perform this weekend that will take me out of town on Sunday so hobby time is limited but I did get something done. Permanently installing the Tam Valley Octopus III and attendant remote relays will require me to mount them in close proximity to the control panel. There isn’t any large wood surface in that location or in any other for that matter, this being the downside of non-solid wood topped baseboards. There being no wood surface available, I determined to provide my own.

I measured the boards and pondered their optimal orientation in relation to each other and to the various connections that would need to be made. I then cut a 3″x 8″ hardboard rectangle, drew some guide lines on it and attached the boards with 3/8″ #4 wood screws.

It isn’t fancy but all the boards are securely mounted so that plugging and unplugging won’t cause something to come loose. I will screw the board to the underside of two subroadbed sections so that the board is accessible between the baseboard bracing.


The blue terminal blocks all handle power of some sort: track for the relays(red boards) and servos for the Octopus board. The black connectors on the relays and the C 0-7 header on the Octopus connect to the controllers on the panel via Y-cables. The less ideal bit is that the cables to the servos connect on the header on the left side of the Ocotpus. This was the least bad choice since the connector for the Remote Alignment board (right side) needed to be easy to get at since it’s cable will get repeatedly plugged and unplugged at least until I get things all set up.

As a note, the relays are what seemed like the best solution for switching frog polarity when I bought the Ocotopus-III several years ago. If I was doing this from scratch, I would use a Frog Juicer instead especially now that I have used one and seen how simple it is to wire up.

Diamond Frog Juice

I have been test running back and forth looking for mechanical flaws in Comstock Road’s trackwork. Whilst so engaged, I discovered that the two isolated and as yet unpowered frogs on the diamond are both as long as the SW-8’s trucks and spaced almost exactly the same distance apart. This was obvious as the locomotive persistently lost power crossing the diamond at slow speeds. (Faster speeds allowed the capacitor to get it across the gap in time).

Fortunately, I recently purchased a Tam Valley Dual Frog Juicer for just this eventuality and got it installed tonight. Several post-installation test runs have failed to produce a stall so it looks like the device is earning its’ keep.diamondfrogjuice

This is probably the easiest installation I will get. Four screws, four wires and done. I think I spent more time reading the instructions than actually hooking it up.

As an encore, I broke out the servo connector wire kit I have assembled from various vendors. The combination of purpose specific three strand wire, connector kit and crimpers will allow me to connect servos to Octopus-III board and control panel. And the vast quantity of parts will allow me to mess up the occasional crimp. Score is 6-1 so far…jrkit

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.

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.