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I want to have 100+ block signals on the layout I am designing and building.   The only way to afford that may block signals is to 3D print them.  I wanted to have 4 different block signals: 3 aspects, 3 and 3 back to back, 3 over 2 and a dwarf 2.  I designed the block signals in Tinkercad and printed them with my Prusa 3i mk3s.  The photos show the 4 block signals.  The third photo is the jig I designed and 3D printed for gluing the parts together.  The lights are 5mm LEDs.  The LEDs are soldered into a small PCB that holds the LEDs in place and magnet wire connect the PCB to a connector at the bottom of the signal.  I can run 8 24 gauge magnet wires through the 4mm ABS tube that is the pole.  There is a board on each block signal so they can be individually labelled.




Wired LEDs have been added to the 3D printed block signals. A small PCB board was designed to hold the 5mm LEDs and connect to magnet wire. The 3 aspect LEDs connected to the magnet wire is shown in the picture. I use a magnet wire stripping tool to remove the enamel from the magnet wire for soldering. I tried solderable magnet wire and scraping the enamel manually and by far the best results are with the tool. The tool has be be used carefully with 28 AWG wire.


I 3D printed a spacer/aligner for the LEDs shown in the picture for a 2 aspect LED. The spacer is press fitted into the block signal and the LEDs are set at the proper depth and space for the hood. The hood is press fitted onto the LEDs. The final assembly will probably also be glued.


This picture shows a 3 over 2 unassembled block signal. The base of the block signal has a recess where a 14mm spacer is inserted. 14mm is needed so that the connectors for the LEDs can be put through a 14mm hole to below the layout. 4 and 3 pin connectors and magnet wires are shown in the picture soldered to a small PBC board. All the components in block detection and signals use connectors for easier testing and debugging problems.


This picture shows the completed 3 over 2 block signal with LEDs and connectors. I am now approaching 15 minutes to solder and assemble a block signal from parts.


My design has compromises to realism for ease of assembly, parts printing and cost.


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Last edited by carl552
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The block signals are O Scale and slightly more than 6" tall.  I made measurements on some purchased O Scale block signals and looked a pictures on-line and the UP block signals near where I live.  I then made CAD drawings with Tinkercad for the 3D printer.  The block signal material cost is less than $1.  It takes about 2 hours to print all the parts. I batch print about 8-12 pieces of each part.  In a week I can have parts for 30+ block signals.  I use a "Silk Silver" PLA plastic for the metal parts and black PLA plastic for the face.  The pole is a 4mm diameter white ABS tube.  I am debating if it should be spray painted silver.  It takes 15-30 min to solder and assemble one of the block signals.  I hope to get faster at the assembly.  I should be able to do batch assembly in less than 10 min each.

I was modeling these:

These printed but were delicate; The approach you took is better. I should have used a Plastruct tube instead of printing the tube. Like I said I may try these again with a stronger resin.

Attached is the .stl file for the double head signal. The openings for the signal lighting fit 3mm LEDs.


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Files (1)
Last edited by AlanRail


I love the details in your designs.

One of my challenges was to have room behind the front face for the 5mm LED and PCB board (I only wanted the LEDs to peek out of the face)

When I get home I will post pictures of the PCB board and the wiring.

I also have a designs for "Darth Vader" face plates.  I like the look, but it is harder to see the LEDs.

I also preferred don't to show the wires and didn't know how to do that with the bends in the pipe.

There is also an O-Gauge block signal on Thingiverse but it has a "No Derivatives" License.

The designs are made were done when I was learning to use Rhino, so now I can do better.

Also I have a better printer now.

I was thinking that a better light than an LED would be an SMD

2835 SMD LED - 6000K - Cool White - Surface Mount LED with a clear 3D printed lens fitted into the space; The clear resin can be colored with red, green and yellow resin tints.  It may be way too costly to do this.

Instead, maybe i'd add a red, green and yellow translucent plastic pieces between the SMD and the Lens. Or use SMDs that have a color. Do they make that?

Hi Jeff,

The Gerber and NC Drill files are zipped together.

Block2LEDv5' (7.0x13.3mm) - 2 aspect (LED) Head

Block3LEDv3 (7.0x21.6mm) - 3 aspect (LED) Head

BlockSignal 1Basev3 (6.4x34.4mm) - Base connector for a single 3 aspect signal

BlockSignal 2Basev2 (11.4x32.4mm) - Base connector for a 3 over 3 or 3 back to back aspect signals

BlockSignal DBasev2 (11.4x18.4mm) - Base connector for a single 2 aspect signal 

BlockSignal SBasev2 (11.4x30.5) - Base connector for a 3 over 2 aspect signal



@TomNe posted:


Tried to upload your 3d files to third party for printing and it failed due in their words "too many Shells".  Do you have the block signal parts in single shell files.



I printed these just fine you need to find a different person who knows how to use there printer and slicer. What are you wanting quantity and types maybe I we can work something out?? Email is in my profile.

Last edited by Shawn_Chronister

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