Watch Band Adjustment Tool / Pin Extractor

I needed to adjust the band length of a new watch and wasn't happy with the adjustment tools I found.

I am too forgetful to stop midprint to put M4 nuts in so the printer would sit idle for hours. I am too clumsy to drill a hole into the center of the front end of a M4 screw and put a tiny pin into it. And I am too lazy to take a scredriver and make the many turns needed with the fine threads of a M4 screw when actually using the tool.

Some other tool I found (https://makerworld.com/de/models/1584337-watch-pin-extractor?from=search#profileId-1672415) uses a 4mm bit in a printed screw, which solves the issues above. It may be unjustified, but I didn't like the 4mm bit being turned with the screw, potentially scratching the pin.

For ease of use, I needed the tool to be sitting on the table. Therefore the tools needs "feet" so the band can run through under it.

So this is hopefully a solution that works for you, too:

• You need a 4mm bit, e.g. from a smartphone repair kit. I'm using 0.8mm torx bit, but any with a fine enough tip would do.

• Part 1: horizontally sliding holder for 4mm bit

• Part 2: screw with grippy wheel

• Part 3: base body

Printing:

• No supports needed (print the base body standing on the front end surface)

• Single-material PLA prints will work perfectly fine.

• I printed in PETG, as I wanted to have some parts (wheel grip, feet, mounting surface) made of softer material (TPU). See attached .3mf

• 15 % infill, 5 perimeters for structural strength are more than enough.

Mounting:

• Insert the 4mm bit into the holder (you can also do it later, but it's just easier now).

• Insert the bit holder into the back of the base body.

• Screw the screw in.

The watch band pin has to be pushed only a few millimeters before it can be easily pulled by hand.

Let me know if there is any need for adaptions of the bit holder, e.g. for standard 6.3mm bits or for using a thin nail instead a bit.