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Linear Rail Eggbot

Download free 3D printer designs Linear Rail Eggbot, 8ranDownload free 3D printer designs Linear Rail Eggbot, 8ranDownload free 3D printer designs Linear Rail Eggbot, 8ran

3D model description

Does the world really need another eggbot? At first I didn't think so, but then I ran across Niko's eggbot design over on OpenBuilds ( and got super inspired. I loved the look of the extruded aluminum rails, but wanted a design that hid the ends and felt a little more balanced (where the egg motor was over the rail instead of being mounted off the side of it). This is my attempt - I hope this helps someone. Also, this is not a cheap project!

I used Niko's pen arm STLs so have not provided those here.

Instead of using a hardware store hinge for the pen arm, I cut out a piece of polypropylene and screwed it in. My goal was to eliminate the possibility of any slop in the mechanism. Polypropylene is a very resilient plastic for applications where it will be bent back and forth repeatedly. Mine came from a yogurt tub ;)

I'm sure I missed something, so leave a comment if something isn't clear about the design and I'll try to get back with you. However, I can't help you troubleshoot your own project or Inkscape. Be sure to read over the Eggbot Wiki over at Evil Mad Scientist

Parts from Open Builds:
2 × Low Profile Screws M5 (10 Pack) (Length: 8mm)
1 × Low Profile Screws M5 (10 Pack) (Length: 10mm)
1 × Low Profile Screws M5 (10 Pack) (Length: 20mm)
1 × Low Profile Screws M5 (10 Pack) (Length: 27mm)
1 × Button Head Screws M3 (10 Pack) (Length: 6mm) (to attach pen arm motor to NEMA motor mount)
1 × M5 Tee Nuts (10 Pack)
2 × Ball Bearing 625 2RS 5x16x5
1 × V-Slot® 20x80 Linear Rail (Length:250mm)
1 × Motor Mount Plate for NEMA 23 Stepper Motor (the NEMA 17 fits too)

Parts from Evil Mad Scientist:
1 x EiBot Board
1 x Precision Egg Coupler
1 x Aluminum Pen Arm Backer

Materials from Other Sources:
1 x M5 tap to cut threads in the end of the extruded aluminum rail
2 x NEMA17 Stepper Motors
1 x MG90R Servo
1 x 5mmx100mm shaft
2 x shaft collars (5mm bore)
1 x Knob to hold the pen (drill and tap the pen arm first according to Niko's instructions)
4 M3 screws to mount egg stepper motor
4 x little screws for the polypropylene pen arm hinge
4 x little screws to hold EiBot Board in place
9v, 1.5A Power Supply (center positive, 2.1 x 5.5 mm barrel plug)
1 x Spring (goes on the 5mm shaft to provide tension to hold the egg - I had one laying around)
1 x rubber stopper thingy
1/8" cable sleeve
1/4" cable sleeve
Heat Shrink Tubing


  • 3D file format: STL



I design and print stuff for my kids. I hope yours will enjoy them too!



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