If you've tried to use any of the existing fan shrouds for the PB Simple Metal (or really any printer), you've probably found that a lot of the air being driven by the 40 mm PC case fan is actually just going backwards out of the shroud; the fan can't develop enough pressure to drive the air through the shroud and onto your print. This even happens with the official Printrbot fan shroud, just put your hand behind the fan and feel it for yourself.
I designed this mount to securely hold a 50x15 mm blower fan (also called a centrifugal fan, or cage fan, or squirrel fan) onto mounting holes designed for a 40 mm fan. I designed this for the Printrbot Simple Metal, but it will work with any printer that accepts a 40 mm fan. By pairing this mount with the (optional) 40 mm fan spacer, you can use a blower fan with any existing PB Simple Metal shroud you can find. The blower ensures strong airflow through your shroud, making your prints happier.
You may need to enable Cool head lift so that the printer stops to allow the small layers of the fan mounting posts to cool down.
- 1x 50x15 mm blower fan like this one from eBay. They cost <$10.
- 1x 2-pin to 2-pin fan cable extension to reach the Printrboard. The stock fan's cable is 75 cm long, so you'll need a similar length.
- These extensions are actually really hard to find because most PC fans use 3- or 4-pin connectors so that their speed can be controlled intelligently. Printrbot doesn't do that, it just uses 2 pins for GO FAST.
- I recommend just grabbing your soldering iron or wire nuts and splicing more wire into the middle of the fan's cord.
- 5x 25 mm M3 screws, four for attaching the mount to the printer and one for attaching the fan to the holding arms. I really like socket head hex screws to match the factory Printrbot screws, here or here.
- 5x M3 nuts. I bought this kit of nylon M3 stuff so I use those.
The snout of the blower fan should be a snug press-fit into the opening, and the fan is sandwiched between the arms and screwed in to secure it in place.
The optional 40 mm spacer item should be used when a shroud is designed to stack on top of a 40 mm fan — the official Printrbot fan shroud, for example, or the Improved Printrbot Fan Duct by 50an6xy06r6n shown in the example photos. Otherwise you can screw the shroud straight to the bracket, or omit the shroud altogether and just use the blower fan by itself.
20 Nov 2015
14 Jan 2016
- One-piece version released, old three-piece version obsolete. After much head-scratching I figured out that there's no good reason why this object should be broken up into three separately-printed parts, as it was before. The old version is still here and downloadable, but it is marked obsolete and users should use the one-piece version instead.
- Fixed mounting hole alignment.