Replaced by http://www.thingiverse.com/thing:1652
I got tired of manually untwisting filament while my MakerBot prints. There are multple spindle designs on Thingiverse, but they all use laser-cut parts instead of printed parts. I don't own a laser cutter, but I do own a MakerBot (#238), so I decided to design a spindle that can be printed.
This is the early result and somewhat flimsy. I'm releasing it in its current form in the hope that it will be useful even though I don't consider it complete. My to-do list includes tying the legs together and providing a way to prevent the filament from unspooling while it's not in use.
STL and GCODE files
This set of files is adjusted for my printer; the fit may or may not be correct on yours. Just in case, the part generation script (spindle.py) has many adjustable parameters.
- 2 skate bearings.
- 2 M3x16 screws (you should have plenty left over from building your MakerBot).
- 2 M3 nuts.
- 12 1/4" x 6" dowels. These are the radial dowels. You may choose different length.
- 6 1/4" x 6" dowels. These support the filament. You may choose a different length.
- 4 1/4" x 7" dowels. These are the legs. These must be longer than the radial dowels.
- spindle_inner_ring (2). This is the part which holds 6 rods in a radial pattern.
- spindle_inner_ring_cap (2). This part helps lock spindle_inner_ring into the bearing.
- spindle_outer_ring (6). This connects the radial dowels to the filament support dowels.
- spindle_bearing_support (2). The legs connect to this. It holds the bearing.
- Press 3 radial dowels into a spindle_inner_ring. Skip a hole between each pair of dowels.
- Slide a spindle_outer_ring over each radial dowel. Orient each ring so that the holes for the filament support dowels face away from the spindle_inner_ring's bump.
- Slide 3 more radial dowels through the outer rings and press the dowels into spindle_inner_ring.
- Press a bearing onto spindle_inner_ring's bump.
- Press a spindle_inner_ring_cap into the other side of the bearing.
- Use a M3x16 screw and M3 nut to hold the bearing assembly together.
- Press 2 leg dowels into two consecutive holes of a spindle_bearing_support.
- Press the bearing into the spindle_bearing_support.
- Repeat 1-8 for the other side.
- Use the filament support dowels to attach the two sides together.
Optional (part of step 10): press another dowel into the centers of the two inner rings.
I used FreeCAD ( http://sourceforge.net/projects/free-cad/ ) to generate the parts. None of the parts are hand-drawn; I created a generation script which builds the parts and exports them to STL. The script makes it easy for you to adjust the parts for your printer.
- Edit spindle.py and change outputPath to the directory you want your STL files to live. Keep your editor open.
- Start FreeCAD. You should see a window docked at the bottom with a tab named "Python console." If not, then use "View->Views->Report view" to open it.
- Paste the contents of spindle.py into the Python console. One of the parts should appear onscreen and a set of STL files should now be in the directory you specified.
Note: there's no need to save the FreeCAD drawing. Treat the script as your drawing.