Fluke 179 replacement Selector Knob / Dial (and also Fluke 177 / 175 ?)

This is my attempt at creating a replacement selector knob (or dial) for my Fluke 179 digital multimeter. I suspect this knob will work for the 175 and 177 multimeters as well. This printed model assumes that you still have the metal hex shaft from the OEM dial. Because of the supports, the replacement knob looks a little rough from the bottom (which is hidden from view when installed), but it looks good from the top. If the printed knob is fully inserted onto the metal hex shaft (see details below), then it also enforces the mechanical CCW/CW stops that are designed into the knob body.

My OEM knob cracked down the middle. It is epoxied back together and shown in the pictures for comparison.

There are a few "advanced" steps in the slicer settings. You can see some of the slicer settings and slicer results in the uploaded pictures.

• Special modeling and settings to increase the number of perimeters around the hex shaft hole without affecting the perimeters of the rest of the knob. This is to improve the strength of the knob around the shaft. (Note that I didn't test that this strength increase is actually necessary.)
  • The space around the hex shaft is modeled as a separate body so that the number of perimeters can be set for this body separately from that of the main knob body.
  • Because of the separate body for the hex shaft hole, the STL file needs to be imported as a "single object with multiple parts" to place the hex_hole body in the correct position within the main knob body.
  • The number of perimeters is set to 3 for the "hex_hole" body. The number of perimeters is left at the default (2) for the main knob body.
• I set the layer height to be 0.2mm for the first 2mm and to be 0.1mm above 2mm. This was just for cosmetic reasons to improve the layered appearance of the shallow curves on the knob surface. (I tried 0.1mm layer height across the entire model, but it didn't print well with the support material for the first couple of millimeters.)
• Support material is enabled.
• I put a snug "support blocker" cylinder over the hex shaft hole to prevent it from being filled with support material.

I also uploaded a STL with a single body model (without the separately modeled body around the hex_hole) in case you want to try other options for strengthening (or not) the walls around the hex shaft hole.

The hex shaft hole is slightly tapered for a tight fit on the metal hex shaft. To get it inserted all the way, I ended up taking off the front cover of the Fluke 179 and tapping the metal hex shaft fully into the knob from the back (from inside the cover) with a hammer.