I've only had my TwoTrees SK1 for a week now, and have had to remove the front toolhead cover to disassemble the extruder & hotend twice already. Since my hands don't work especially well these days, dealing with the poorly designed cover that hangs on the PTFE tube, attaching with screws that are so tiny they're likely to become lost one of these times I'll be dismantling it, it was quickly apparent that a change would be in order.
I'll often do a quick search for something I'm preparing to model, and sometimes I find somebody has already done most, if not all of the work for me, and I found Hassla's “SK1-Fanshroud-Backshroud-Partsfanduct LED”.
Hassla modeled a complete three piece cover set for the toolhead, as well as a fan duct intended for shining LED's down onto the model being printed. It's a fantastic piece of work IMO. Hassla's model is at: https://www.printables.com/model/746102-sk1-fanshroud-backshroud-partsfanduct-led
Hassla's model addressed most of the issues I had with the front and rear covers, except for my personal difficulty in dealing with the tiny screws that attach them to the toolhead. Since his design was 99% of what I was looking for, I simply opened up the screw holes to form slots, so that these covers may be slid on to the screws while they're already in place, and then snugged down. Since I no-longer have to remove the screws to remove the covers, I'm far less likely I'll lose them. Now I simply loosen those four screws and slide the covers straight out and off while leaving the screws in place. Once whatever maintenance is being done to the hotend or extruder, I simply slide either cover back on and snug those four screws.
I've only included the front and rear cover here as they're the only parts I I've altered. I haven't modified the geometry of Hassla's model in any way, so if you need a top cover, or duct, the parts from Hassla's original model should fit to these nicely.
I printed these as oriented in the STL's with tree supports to buildplate only for the front cover, and since I printed the rear cover face down, I used “normal” supports to “touching buildplate”.
UPDATE 01222027: I decided I liked Hassla's covers so much that I thought I might spruce it up a bit by adding the “TwoTrees” logo cut-out from the top of the front cover and add “fuzzy skin” to the exterior of both covers while slicing. I left the unbranded front cover here and added a second front cover with the logo. Use whichever front cover best suits you.
The author remixed this model.
I slotted the holes for the tiny 2mm screws that secure the front cover to the toolhead. I liked Hassla's front cover on my SK1 so much, I decided to open up the mounting screw holes for his rear cover and add that here as well.