Update: Added a new version that is compatible with both the K1 and K1 max. The cooling performance is unchanged and the old versions are still there if you prefer those. The changes are:

• Updated appearance - Like me, it looks better in person than in a picture.
• Reinforced the top holes. - I had a break around one of them when removing the cover.
• One file with for K1 and K1 max. This also makes for easier access to the Lidar port in case someone wants to make a remix with LEDs.

Features:

• Better cooling than the stock cover for overhangs (all directions) and bridging. The test prints below were printed back to back with the same g-code. The difference is consistent with many test and regular prints. The air flow difference can be felt by hand (and seen if you want to put a cup of water underneath it).

• About 33% lighter than the stock cover when printed in ASA.
• Easy to print and requires no supports. Its been heavily tested as I have printed about 3 dozen prototypes and fixed any issues as I went along.
• Easier to install and remove than the stock cover due to bigger clearances overall (particularly between the fan and breakout board connector).

Notes:

• You will need to keep the fan on when printing high-temperature materials, including the first layer, to avoid overheating the cover near the outlets.
  • I keep the fan at a minimum of 10% when printing ABS at 260 C extruder and 110 C bed. A lower fan setting may also work but 10% has not caused any problems.
  • Keeping the fan on is not necessary with PLA, TPU, or (most likely) PETG.
  • You can see many warped ducts in the last pic of the slide show. That was from trying to eliminate this problem. It was by far the most persistent and irritating issue and, unfortunately, keeping the fan on is only solution I found. On the bright side, attempting to eliminate this problem led to many other improvements.
• The cover may hit the auxiliary fan duct during the first homing pass. This has no affect on either the cover, the fan duct, homing, or printing. However, it may make a annoying noise at the end of the print.
• Big props to Henlor's K1 models as they made the modelling and testing process much easier (its Henlor's hot end and carriage models in the CFD diagrams).
• The test print is Teaching Tech's “Cooling fan test torture test”
• If you are interested in the auxiliary fan duct in the cover photo, click this link. It's quieter than the stock fan duct.

Print settings:

• Model is in the recommended print orientation.
• I recommend ABS or ASA. PLA and PETG may also work. The one time I accidentally printed ABS (260 C nozzle, 110 bed) with a PLA prototype, the cover warped at the top but the duct outlets did hold up very well (better than some ASA prototypes). Its also possible that I accidentally annealed the PLA cover. So, it could have been a fluke.
• Ensure you get good layer adhesion. The model is meant to be flexible. If you print too fast or at too low a temperature, the model will be fragile.
• Lowering acceleration (<3000 outer wall) will help keep the sides clean. Portions of the sides will vibrate when printing resulting in zits. That said, I have never print fail and any zits can be easily cleaned up with a bit of sand paper.
• 2 Walls at a width of 0.5 mm.
• Layer height is fine at 0.2 mm or less. I use 0.16.
• I get better results without supporting the 27.5 mm bridge at the duct inlet. That said, you can use a tree support if you wish.

Please leave your feedback and enjoy.

Rick

Updates:

• Added a version that allows access to the Lidar port.
• Added step file to make remixes easier. Please don't sell derivatives of my design. It started free, it should remain free.