Shoe dryer

While looking for a shoe dryer, the original model looked like one of the best available, but it unfortunately had no Bill of Materials, and the photos do not make it clear which parts were used either.

I had a 120mm 12V fan from an old PC lying in a parts drawer, so I decided to remodel the lower body to fit that. That worked, but the shoe inserts were fitting very loosely into the lid, causing them to stay in the shoe when it is removed. The lid also could not be used with the screw holes near the fan location, as they would interfere with the 120mm fan.

This turned out to be almost a complete replacement.

I used a USB-C PD Decoy, which provides a USB port and will select 12V from a PD-compliant charger. The fan came from an old PC case. I just cut off the plug and soldered the power leads to the decoy board. I bridged the gate to select 12V operation. If I had to do this again, I would opt for a decoy that does not need soldering to select a voltage - it is quite small and is a bit annoying to do, I'd go for something with switches. The decoy will only select the correct voltage from chargers with that ability (PD standard), otherwise it will run on 5V, which provides much less airflow but is very quiet, so it is still usable. You could also select 9V for an in-between option.

I used hot glue to hold the USB board in place.

There are 2 models of the lower body: one for self-tapping screws (3mm holes) and one for 4mm thread inserts (5mm holes). The fan is held in with 4mm x 30 screws, and the lid is fastened with 4mm x 12mm pan-head machine screws. The 30mm screws are the bare minimum length - there are only a few threads worth of engagement, but there is no load on them.

Parts:

• 120 mm 12V fan

• USB-C PD Decoy, set to 12V

• 4 x 4mm x 30mm pan head machine screws

• 4 x 4mm x 12mm pan head machine screws

• 8 x 4mm thread inserts

• Glue to hold the USB board in place

• Soldering iron:

  • Some soldering required

  • Installing thread inserts

Printing:

I've printed everything in PLA with srandard profiles from PrusaSlicer, no special adjustments are needed. The top of the rounding of the fan cavity was printed with support, as well as the top arch of the USB port.  The bosses for the screw that hold the fan in place also need supports. There is a picture showing all the supports I have used. The tabs where the lid mounts do not need support. The foot pieces were printed in an upright orientation without any support. The lid prints upside down for a smooth top finish, the lower body prints "as is".

A 0.4mm nozzle with 0.15 - 0.2 layer height or a 0.6mm nozzle with 0.25-0.32 would both work; there are no real fine details, and considering the size of the print, I'd opt for a 0.6mm if available. I printed this on my XL, but this was originally intended for an Ender 3 and would easily print on an i3 and up as well.

A note on licensing: The original model dictates the terms of the license, which limits my options, but please go ahead with suggestions and/or improvements.