Whatever you want to use :-) • If you work exclusively with PLA, it is quite enough if they also make the upgrade with this material...really! • If you also want to continue working with ABS and more specific materials, please make the upgrade, at least with ABS. • Take 5 mm wide Kapton film and insulate so the Hotend as much as possible. If you make it as suggested then you reduce external contamination on the Hotend effectively, and an improved temperature-stability is achieved. • The red marked areas in the design, these are necessary support elements. If you want This Design Print in PLA, then no further optimizations in the slicer are regularly required. You may want to print with very low temperatures, so that the support elements can be easily removed from the object later. For most PLA varieties I recommend a temperature in the range of ~ 195 °. Small addition: • The fan cages are not made of metal and much more sensitive than the originals. That is why it is a good idea to print each variant more than once to get a spare part is in stock. - Smaller drooping deformations near the hottest zones can be easily corrected with a nail file. • Before printing of very large objects, you need to check if risk of collision with the glass bed retaining clips. The perforated insulator bolt at the ColdEnd (Teflon-piece), allows you to slightly adjust the Z position of the Hotend. Then be sure to realign the print bed. • The CPv9 design is slightly wider than the original UM-design, we lose a few millimeters building area. Please also indicate what adjustments need to be optimized in the Cura-machine settings. • The UM-original cages may differ slightly in their dimensions, since it is folded sheet metal, and sometimes it might already be too bent on some machines. Of course, several measurements at different UM2s are good for adaptations so people, please join...