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 (https://openbuilds.com/builds/niko%E2%80%99s-egg-painter-robot-openbuilds.1953/) 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 https://wiki.evilmadscientist.com/The_Original_Egg-Bot_Kit

Note: Google Sketchup file is included

Original Size Images for Reference
Front View:
https://thingiverse-production-new.s3.amazonaws.com/assets/13/be/f5/6d/a7/Front.jpg
Side View:
https://thingiverse-production-new.s3.amazonaws.com/assets/fb/87/08/57/09/Side.jpg
Bottom View:
https://thingiverse-production-new.s3.amazonaws.com/assets/ce/59/f7/c6/a2/Bottom.jpg

Video
https://youtu.be/qzW1a53-I5U

Parts from Open Builds:
2 × Low Profile Screws M5 (10 Pack) (Length: 8mm) https://openbuildspartstore.com/low-profile-screws-m5-10-pack/
1 × Low Profile Screws M5 (10 Pack) (Length: 10mm) https://openbuildspartstore.com/low-profile-screws-m5-10-pack/
1 × Low Profile Screws M5 (10 Pack) (Length: 20mm) https://openbuildspartstore.com/low-profile-screws-m5-10-pack/
1 × Low Profile Screws M5 (10 Pack) (Length: 27mm) https://openbuildspartstore.com/low-profile-screws-m5-10-pack/
1 × Button Head Screws M3 (10 Pack) (Length: 6mm) (to attach pen arm motor to NEMA motor mount) https://openbuildspartstore.com/button-head-screws-m3-25-pack/
1 × M5 Tee Nuts (10 Pack) https://openbuildspartstore.com/tee-nuts-m5-10-pack/
2 × Ball Bearing 625 2RS 5x16x5 https://openbuildspartstore.com/ball-bearing-625-2rs-5x16x5/
1 × V-Slot® 20x80 Linear Rail (Length:250mm)
https://openbuildspartstore.com/v-slot-20x80-linear-rail/
1 × Motor Mount Plate for NEMA 23 Stepper Motor (the NEMA 17 fits too)
https://openbuildspartstore.com/motor-mount-plate-nema-23-stepper-motor/

Parts from Evil Mad Scientist:
1 x EiBot Board https://shop.evilmadscientist.com/productsmenu/188
1 x Precision Egg Coupler https://shop.evilmadscientist.com/51-products/accessories/208-coupler
1 x Aluminum Pen Arm Backer https://shop.evilmadscientist.com/51-products/accessories/702-albacker

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 https://www.amazon.com/gp/product/B076XW73Q7/
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 https://www.amazon.com/gp/product/B071G5L29C/
1/4" cable sleeve https://www.amazon.com/gp/product/B071JH14WZ/
Heat Shrink Tubing

Software:
Inkscape http://inkscape.org/en/