Dual fan mount for Printrbot Simple Metal

thingiverse

After publishing my experiment on how dual fans and fan shrouds impact overhang success and appearance, I became curious about whether using two fans would boost my results. Nobody had created a frame to hold two print-cooling fans onto a Printrbot Simple Metal, so I came up with my own design. Using two fans instead of one improved the printing success and surface quality of tall and thin features like spikes, horns, screws etc, and lessened warping in general. This frame connects to the existing 40 mm fan mount holes and provides an additional 40 mm mount ahead of the hot-end (the bed levelling probe stops me from placing the fan beside it, which is how other printer manufacturers have arranged them). The two fan mounts are equidistant from the hot-end, so you can use any existing fan shroud and be sure it's aimed at the right spot. The demonstration images show my printer prepared for a test print, with blower fans through my universal blower fan mount giving EricY's Improved Fan Shroud air to the working face from two directions. Which fan shrouds should you choose? According to my experiment, different kinds of fan shrouds work well for various things: Fan shrouds that aim air at the nozzle do well with overhangs and thin features. Fan shrouds that blow air widely across the printing area work great at reducing warping. It's no surprise that the results show you should use one of each! Here are the fan shrouds I employ: For the focused shroud, I use EricY's design. I installed it on the left side of the printer, but I don't believe it matters since the dual-fan mount can take any shroud interchangeably. For broad airflow, I'm actually using the blower fan by itself without a shroud, which is what the experiment showed worked best. I'm creating some shrouds on my own to apply what I've discovered. Important points! Don't hot-swap your cooling fans. There's a chance of damaging your controller board. Always switch off and unplug your printer before dealing with its wiring. You'll need M3 screws and nuts for fitting this frame and its accessories to your printer. I used various screw lengths from 15 mm to 30 mm, relying on the shroud I was testing. Printer settings: * Brand: Printrbot * Printer model: Simple Black * Raft: No * Supports: No * Resolution: 0.2 layer, 0.4 nozzle * Infill: 50% * Notes: The angle of the walls is 61°, which can be achieved without support. Designing This The most interesting part of the design was figuring out the spacing and angles to get the frame goal of holding a second fan at the same distance and angle as the first one. The essential thing you can do when designing something to fit an existing object is make a 3D placeholder for it — once you have that, just slap some shapes on it until it looks right. I made a placeholder of the printer's gantry by measuring the original fan mount and hot-end and making a 'sketch' with those dimensions using primitive shapes. Then I got a 360° fan shroud like this one and fitted it to the placeholder as it would appear in real life. Then I duplicated that setup and turned the copy 90 degrees, placing the copy until the space for the hot-end in the shroud was positioned in the same place as the first one. Working with a template makes it easiest for me to design things. Changelog: