Distal pen arm for EggBot

thingiverse

This is a customizable version of the pen holder arms used by EggBots, available at EvilMadScientist.com/productsmenu/51-accessories/205-distalarm. It was designed to be a solid one piece object without any nuts and bolts for holding it together. It turned out to be 2 pieces glued together as that is easier and faster to print this way. To allow fitting different kinds of pens such as Sharpie Ultrafine and Sharpie Fine markers the pen arm itself contains a hole for a pen adaptor module. This way when you want to change pens you only need to replace the adaptor with another one and get a tight fit on any pen of yours. I supplied STLs for adaptors for the ultrafine Sharpie and for the fine-point Sharpie, and also made available a configurable OpenSCAD file where you can change the diameters around. The OpenSCAD file also allows the customization of various parameters like the length of the arm the thickness of the piece and the diameter of the bolt fixing the pen. Extra parts needed are 1x M3 nut, 1x M3 bolt. It is compatible with Basic, Deluxe, and Ostrich EggBots. You can use the same S90 TowerPro servo on this arm as you would with the one from EvilMadScientist. Update 1 @ 2015-04-12 I increased the thickness of the thin part of the pen arm from one layer thickness (0.2mm) to two layer thickness (0.4mm) to increase durability. I modified the OpenSCAD script printing the pen adaptors so that you can specify the top and bottom diameter of the adaptor module in order to model the shape of the pen better. I updated the ultra fine sharpie STL to have better dimensions. The supplied STL files have been generated from the OpenSCAD file and are configured for a standard EggBot, use with an M3 bolt and nut as pen fixers and contain adaptors for the ultrafine Sharpie and the fine Sharpie markers. Print all STL files Glue the stepper arm and the pen arm together Put an M3 nut into the shaft designed for it, found on the inside of the hole for the pen adaptor on the pen arm Insert the pen adapter (fine.stl and ultrafine.stl) into the hole designed for them on the pen arm Pretty straightforward. If you want to customize take a look at the SCAD file it even has comments. The most important settings in it are: l1 size of the stepper arm l2 size of the pen arm thickness thickness of the arms gap gap to leave between objects that should fit into each other For printers that are not 100% exact Like mine. screwDiameter diameter of the bolt fixing the pen in its place nutDiameter diameter of the nut for holding the bolt nutThickness size of the shaft to house the nut diameter parameter for the penHolder module Diameter of the pen to print an adapter for At the end of the OpenSCAD file you will find module calls that you can comment out to obtain the specific parts you want.