Why this mod?

* Tempered glass hotbed takes time to cool down

* Non-magnetic removable plates aren't easy to remove with low-profile clips

Features

* efficiently cools down the hotbed by blowing along it

* designed for the standard 80x80mm fan

* an easy print with almost no supports

* benchmarks show the cooling time decring TWICE, going from 60 to 30C in 15 minutes

* can be used with OctoPrint plugin like GPIOCoolDownFan for automated operation

Tradeoffs

* rapid cooling from very high temperatures can potentially make the glass to shatter - AUTHOR TAKES NO RESPONSIBILITY FOR ANY POTENTIAL DAMAGE

Requirements

* 80x80mm fan and a way to power it (external or printer's power supply, control schematic to switch it on/off)

* 2 or 4 fan screws

* PLA or other filament of your choice

Printing guide

* funnel - print as is, no support

* clamp - print as is at 45 degrees - this requires minimal support

I used OrcaSlicer with 0.2mm layer height, 10% cubic infill, 230/60 for the nozzle/hotbed temperatures. Black eSUN PLA-Matte for the material.

Assembly guide

* put the funnel half way through the clamp

* put the clamp on to the prnter side

* adjust the level fo the funnel to blow along both top and bottom surfaces of the hotbed

* IMPORTANT: with the motors off, move the extruder to ensure it never hits the funnel - adjust if needed

Post-print fast cooling mod for Ender-3 S1