User:Wayland
Release status: Experimental
Description | A new belt-drive repstrap loosely based on Darwin and the McWire Cartesian Bot
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The Golem is a work-in-progress RepStrap. It'll be big and cheap, as much as I can make it. It probably won't have a great print area for its size, but I don't need to keep this thing on a desk. Y axis runs on aluminum channel, X axis will run on steel rod, and z axis will be on threaded rod, with the print platform moving. I'm thinking about using pololu sepper drivers and the sanguino for a motherboard. For the extruder, I might use Adrian's geared extruder, if I can get someone to print the parts for me...
Current Progress: Need pulleys and belt for z-axis.
Contents
To Do List
(things will be listed as they are foreseen, stricken out when they are completed, and deleted when they are documented and photographed.
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Cut and drill angle and channel for the z-axis -
Put z-axis legs together -
Put in threaded rod -
Build a coupler for the stepper and the threaded rod - Obtain timing pulleys and belt
- Build print platform from
Parts
I have basically a scrapyard in my backyard, so a lot of these parts are salvaged. This is a prety cobbled-together thing, using whatever I have or can get cheaply
- Aluminum plate, channel, and angle - Salvaged, cut to size with circular saw, drilled with drill press
- 3 Stepper motors - Cheap surplus-store Molon steppers (these guys) - Almost no specifications, I will test them and figure out voltage and current once I get my power supply and drivers. They don't have a great resolution - I'm thinking I will gear them. If they're no good, I can always buy some NEMA 17s.
- 8 skate bearings - Salvaged from an old generic-brand skateboard. These are pretty nice bearings and perfect for what I have in mind. These are just for the y axis - I'm gonna need to find or buy some more for the carriage.
- Threaded rod - Salavaged
Y-Axis
I really liked the self-adjusting bearing arms used in the McWire Cartesian bot, so I made something similar; instead of using a platform, though, I'm using separate (for now) carts that will have the x-axis running between them. Each cart will be driven by a separate belt, both of which attach to the same stepper.
The cart is made of sheet aluminum , as are the bearing arms. The fixed bolts have on them: a spacer, the bearing arm, the bearing, and the nut. The floating bolts are just the arm, bearing and nut. There is a small hole on the inside of each bearing arm; I had planned to use springs like in the McWire, but I only had rubber bands around to test it with, which ended up working fine. If the rubber bands break, though, I'll switch. These carts run on a frame I made from aluminum channel.
Z-Axis
The z-axis runs on four threaded rods arranged vertically in the frame's corners. There are holes in the corners of the x-y frame which the threaded rods go through, and, over the hole, is a washer and a bearing to lessen friction. On the bottom of the legs are guides to keep the threaded rod straight and more bearings. A stepper will be powering one threaded rod, which will then power the res of them via pulleys and a timing belt.