Introduction: Halloween Happy Ghost Pin Walker.

About: Our grandkids keep me busy!

With Halloween only a few weeks away, and one of our grandsons about to spend another Saturday night at our home (he's so exited about Halloween that when here, he wears one of the numerous Halloween costumes his grandmother, a.k.a. my wife, bought for him), I designed this "Halloween Happy Ghost Pin Walker", which is based on my previous pin walker platform, to compliment his ghost costume.

I designed both a dual and single extrusion happy ghost, and Cura 4.2 indicated the dual extrusion ghost would require about three hours to 3D print. So it, and the remaining parts, became a Friday night "overnight print". A few minutes of cleanup, soldering and assembly Saturday morning, and "Halloween Happy Ghost Pin Walker" was ready for our grandsons arrival.

As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make plenty of mistakes.

Designed using Autodesk Fusion 360, sliced using Cura 4.2, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

One final note, I receive no compensation in any form for the design, parts and/or materials used in this model.


I used the following supplies:

  • Light machine oil.
  • Solder.
  • Double sided tape.

Step 1: Purchase, Print and Prepare the Parts.

This model uses the following non-3D printed parts:

  • One 3.7vdc 100ma Lithium Battery (
  • One JST PH 2-Pin Cable (
  • One N20 6VDC 150RPM gear motor.
  • One micro switch (Uxcell a12013100ux0116 High Knob 3P 2 Position 1P2T SPDT Vertical Slide Switch, 0.5 Amp, 50V DC, 50 Piece, 3 mm).

You may also need a suitable battery charger.

For the 3D printed parts, I've included the file "3D Printed Parts.pdf" containing the part names, count, layer height, infill and support settings for the 3D parts I printed. "Ghost.3mf" is the dual extrusion ghost, and "Ghost.stl" is the single extrusion ghost, you only need one or the other.

This is a high precision print and assembly model using at times very small parts and in very tight spaces. Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on you printer, your printer settings and the colors you chose, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step.

The model also uses threaded assembly, so I used a tap and die set (6mm by 1) for thread cleaning.

I used light machine oil for lubrication of the gears and axles.

Step 2: Wire the Ghost Motor and On/Off Switch.

To wire the ghost motor and on/off switch, I performed the following steps:

  • Cut the wires on the JST connector to 40mm in length, then stripped and tinned the ends.
  • Soldered the black wire from the JST connector to the motor "-" terminal.
  • Soldered the red wire from the JST connector to one of the outside switch terminals.
  • Soldered the center switch terminal to the motor "+" terminal.

After wiring, I connected the JST connector to the battery and operated the switch to turn the motor on and off.

Step 3: Assemble the Base.

To assemble the base, I performed the following steps:

  • Pressed the gear motor into "Base.stl" such that the motor shaft was 3mm above the motor gear plate.
  • Pressed "Gear, Crown, Motor.stl" onto the motor shaft.
  • Slid "Mount, Ghost.stl" down from the top base assembly and secured in place with two "Axle, Body.stl".
  • Pressed one "Cam.stl" onto the short hexagonal shaft on "Axle.stl".
  • Positioned "Gear, Crown, Axle.stl" inside the base assembly over the smaller axle hole.
  • Slid the longer hexagonal shaft of the cam and axle assembly into the base assembly larger axle hole.
  • Pressed the longer hexagonal axle shaft through the axle gear and out the smaller axle hole in the base assembly.
  • Rotated the gear train such that the cam was at its upper most position.
  • Pressed the remaining "Cam.stl" onto the long hexagonal shaft end of the axle assembly such that the cam was at its lower most position (180 degrees from the first cam).
  • Slid one "Leg.stl" into the base assembly and positioned the cam ring over the cam and secured in place with one "Axle, Leg.stl".
  • Slid the remaining "Leg.stl" into the base assembly and positioned the cam ring over the cam and secured in place with the remaining "Axle, Leg.stl".
  • Rotated the gear train until the leg pins were level (one cam straight forward, remaining straight backward).
  • Positioned "Seesaw.stl" over the upper threaded hole on the base assembly and secured in place with "Axle, Seesaw.stl", making sure the center two teeth of the seesaw surrounded the center tooth on the body mount.
  • Secured the battery to the rear of the base assembly with doubled sided tape.

At this point, I connected the motor to a power supply in order to test the assembly. I lubricated and operated the assembly and noted the power consumption to be 18 to 20ma. When completed, I connected the battery to the motor using the JST connectors.

Step 4: Final Assembly.

For final assembly, I performed the following steps:

  • Secured the switch to the inside of the foot using either one small dot of cyanoacrylate glue or a small strip of double sided tape.
  • Slid "Ghost.3mf" (or "Ghost.stl") downward from the top of the base assembly until in contacted the body mount, aligned the ghost mount holes with the body mount holes, then secured the ghost to the body mount using two "Bolt, Ghost.stl".
  • Double checked that the wiring did not interfere with the moving components.

And that is how I printed and assembled Halloween Happy Ghost Pin Walker.

I hope you enjoyed it!