This is a way to mount a 40 mm CPU cooling fan to your Ecksbot so that it blows cool air directly on the part being printed. This helps when printing small parts or tall thin parts, but can also help with larger parts if you're seeing any pebbling around the edges.
- 1. Select a 40 mm cooling fan from your junk drawer, or online, or at a computer store. Mine measured about 50 mm across, and the holes are 40 mm apart on each side.
- 2. Print out the bracket, and test-fit the fan. You will need screws and nuts to mount it. There isn't a lot of clearance between the center of the screw holes and where the outside of the shroud sits, so use screws with small heads.
- 3. Print out the shroud
- 4. Remove the filament from your extruder, then pull the bottom plate off (the hot end). The bracket clips around the right front bearing, much like how the extruder fan mount clips onto the back left bearing.
- 5. Re-attach the extruder hot-end plate.
- 6. Mount the 40 mm cooling fan to the bracket.
- 7. Wire the cooling fan into where the existing Ecksbot extruder fan is wired into at the top of the printer. I suggest disconnecting the existing fan from there and wiring it directly to 12V so that it runs all the time. You want the board to be able to control the new fan.
- 8. The fan shroud should be press-fit into the bottom of the fan bracket. It's a tight fit on mine, but each printer's tolerances are different. If yours doesn't give you a tight fit, then use superglue or ABS glue. I meant for it to be glued. The shroud should point directly towards the hot end, and should be angled down so that when you home the Z axis, the bottom of the fan shroud only sits about 0.5 mm above the surface. It'll likely be a tiny bit too high if you seat the shroud all the way, so you might want to angle it down a very small amount. If it's a good press fit, then you can use a screwdriver to lever the end down a bit.
- 9. Turn the fan on to 50% before you heat up the hot end and keep it on even after your print is done. I added a "M106 S255; fan on full" g-code command at the end of my prints to make sure it stays on. Enable the cooling option in Slic3r (or the cool plugin in Skeinforge?). I find I'm getting best results if I run the fan at about 50% speed all the time, no matter what size of print I'm doing. I also increased the extruder temperature (5 to 10 degrees) and decreased the bed temperature, as long as you don't get adhesion issues. A hotter bed gives you adhesion, but gives you more uneven shrinking in the X/Y direction, I find.