BS Hot Fins and Anti-sag PINDA for MK3S R4 Extruder

This is a remix of the Prusa MK3S R4 extruder.

Adds separately printable hot fins to bottom of extruder body and extruder cover. If printed with ABS or polycarbonate, these help avoid the oft report sagging of extruder thin portions on the MK3S extruder. The fins also let you replace just the sagged portion rather than the entire extruder.

Adds support brace for PINDA clamp to help resist thermal sagging reported by MK3S users printing at higher temperatures.

Only hot fins, extruder cover, and extruder body supplied. Remainder of extruder should be printed from Prusa MK3S R4 extruder files.

Original (uncorrected) Prusa filament path is retained.

Print hot fins in high temperature material like ABS or polycarbonate.
Main portions to be printed in PETG.

Hot fins attach using M2 x 12 mm bolts.

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Change Log

Increased opening diameter of M2 holes of main bodies for easier M2 screw start.

Split fins into separate 3mf preset for for Polymaker Polymax polycarbonate.

Added support brace for PINDA clamp

Polymax polycarb 3mf now has entire extruder main body and cover. Delete items not needed before slicing.

If you have not printed previously with Polymax, coat smooth PEI print bed with glue stick, dissolve and spread glue with wet paper towel, dry at 100C to form reliable bonding surface for Polymax.