Gondola for v-plotter/polargraph

thingiverse

This is my take on the Gondola for a v-plotter/polargraph machine. Its meant to be lightweight, use as little filament as possible, have the pen at the center of the pivot point, not require much in the way of additional hardware (no big bearings needed), be quick and easy to assemble/disassemble, and have a push fit pen holder so I can do quick pen changes. Pen Holder/Organizer: http://www.thingiverse.com/thing:1393182 Pen Depth Setting Tool: http://www.thingiverse.com/thing:1393200 Print Settings Printer Brand: RepRap Printer: Huxley Rafts: Doesn't Matter Supports: Yes Resolution: 0.2mm layer height Infill: 20% Notes: The double arm, weight arm, and pen holder will require printing with support. For the arms, once printed, it is essential that they are clean and free of any support material as they will need to slide around the gondola and past each other. This could be a tricky print or require lots of finishing. I spun my Gondola in a drill for a while to free up the rotation of the arms. Some silicone grease on the pivot point will also help. Post-Printing Assembly: Should be straightforward, but as mentioned in print settings, finishing the pivot parts well is essential. See the assembly pictures. Align the three arms' pivot points with the 'single arm' inside the 'double arm' and both inside the 'weight arm'. Slide the whole thing onto the Gondola and push fit the 'swing arm collar' to keep them in place. The two arms that attach to the ball chain are designed with slots to accept the chain. There is a slight recess on one side of the ball chain sockets. These should both face the same way. When you fit your ball chain, pass the chain through from the other side so a single ball can sit in the recess. Drop the chain through the larger of the two holes at the end of the arm and push the chain up to the end of the arm, and it should stay locked in place. Alternatively, if you are using string, tie it onto the holes in the end of the arms. The pen holder (pen collar) takes an M3 screw to secure the pen. The hole should be about the right size to allow an M3 screw to self-tap, but your mileage may vary. Use a drill and/or a tap if you need to. The pen collar should be a push fit with the Gondola; if it isn't, you might have to tweak your printer settings (or the scad files). The weight arm is designed to take an M4 screw with a large washer at the bottom, packed with nuts (they fit snugly inside the bearings' inner race) and a number of 608 'skate' bearings. You could just tie a suitable weight to the bottom of this arm. How I Designed This Designed in OpenSCAD. Some of these parts are parametric, some aren't, and some are a mix.