Replacement handle for files.
Printed with dual extruder, soft TPE over PLA or PETG cores (an attempt at printing with an ABS core failed).
Designed for files with a tang roughly 8mm wide at the root, 45 to 50mm long and tapered in both width and height. In practice the handle is a bit tight - I might try heating the tang to see if I can get the files to sit a little deeper. The temperature needed to soften the plastic should be well below anything that might affect the file's hardness.
20% or so seems to be fine
The TPE needs to print slow and with plenty of cooling. Printing over PLA is the easiest because the temperatures of the two plastics are similar, and the PLA tolerates the cooling fan without any problems. I find PETG finicky to print at the best of times and using it for dual extrusion seems to make things worse. The upside is the elasticity of PETG allows the handle to get an excellent grip on the tang of the file.
The TPE grip was supposed to be 2mm thick but seems to have come out a little more than that. I was printing the grip with a 0.9mm nozzle and 1mm extrusion width and Slic3r added a gap fill line between the two perimeters. The core was printed with a 0.4mm nozzle and 0.5mm extrusion width. Some of the handles were printed with 0.2mm layer height and others with 0.3mm - both worked fine.
I haven't used the handles long enough to know how well they will last. They feel great in the hand, but I may have gone a little on the skinny side at the narrowest point.