Create a dwarf signal mast from a Digitrax SMBk

The Digitrax SMBK can be dressed as an N-scale main and distant signal. The manual suggests to make it into a main signal by chopping off the top, but it would be a shame not to use the rest on the track. In this post I will explain how I converted a Digitrax Signal Mast Base Kit mast into a dwarf signal plus a single head signal.

Supplies

• A Digitrax SMBK mast
• Thin, flexible wires, 3 colors, each 50mm/2” long
• Brass round tube Ø 2.5 - 3 mm
• Small 10W soldering iron and resin core solder

Cut off the SMBK top

• Cut the upper head from the mast base using a hand saw or motor tool.

Wiring

• Clamp the separate signal head PCB in a mini-vise
• Solder three wires of different colors on the three soldering surfaces, as shown in the previous photo
• The mast will function as Ground return. Solder a wire to the bottom end after the next step

The dwarf mast

• File away one side of the brass tube over a length of 4 mm
• Cut the profile to approx. 40 mm (depending on the thickness of your track)
• Feed the wires through the tube and stick the signal head with 3-component glue

Hood support

• To support the signal cover on both masts, glue two styrene strips 8 mm long/1.5 mm wide on both sides to the LEDs

Connection to the main mast

• Solder 4 wires to the solder tabs of the original mast, so that we can light the dwarf signal.
• Use a 4-pin cable plug to connect both masts under the layout

The signal head cover

• Typical for the Rio Grande signals is the long hood, the so-called Darth Vader
• Make it from styrene
• Paint the mast, the faceplate and the hood matt black

More

• Connect the signal to the flat cable from the Digitrax SE8C DCC Signal Decoder.
• Control the SMBK masts with JMRI according to a prototype of your choice.
• The complete SMBK manual can be found here