a fan base for the cr-10 control box. this piece replaces the original base plate. it screws into the control box with the original screws, the legs attach when screwing in the fans.
the legs are suprisingly solid when filled completely and the holes allow the original feet to be screwed in.
I use two fans in a push-pull configuration. I had two different fans lying around and put the stronger one in the front pushing in, (tested by putting a flimsy trash bag over the base with fans running).
ghetto airflow analysis with some incense shows some exhaust air looping around to the input, the vanes help but haven't completely resolved that issue
the listed remix items were used for inspiration and measurements, but the actual model is designed completely from scratch in tinkercad.
further Side wall reinforcements
- made side walls 1.6mm (2 inner and outer shells, no infill)
- added wedges to the side walls for stabillity while printing
replaced honeycomb grill
- reduced honeycomb supports to 2mm
remade the front/back face
- increased side walls to 1mm for stabillity (and removed sloping)
- added 45° angled bottoms to overhangs similar to curas 'make overhangs printable'
- increased middle screw cutout to 10mm wide (my dingus didnt fit)
legs 100%, plate doesent matter
I used PLA for everything, all pieces can be squeezed onto the bed when plate adhesion (brim / skirt) is turned off, but i havent tried printing this becasue the legs might detach without a brim. (and i designed the pieces one after the other)
no brim / skirt
no supports ( I may have used curas "make printable" feature to get the screw holes slightly conical, I dont remember)
any infill ( 20% triangles? something like that)
brim for better adhesion
support (I used concentric at 1% with 7mm xy distance to support only the floating legs but not the honey comb holes)
exhaust vanes: (experimental)
0.2mm layers (0.4 not tested, the part that slides under the legs is very thin)
skirt ( a brim might break it)
no supports needed
- attach the original feet to the legs
- add two fans to the base plate
- (optional) add the exhaust vanes to the rear side
- screw the fans in with the 4 holes at the center of the plate
- add the legs to the front and rear and screw them to the fans through the base plate
some fans dont work with self-tapping screws, i used m4 screws with nuts for the front (pulling) fan because of this.
- attach the control box. with the original 5 machine screws
be careful, as the plastic is pretty thin and cracks easily
*** blood sweat and tinkercad tears ***
many parts went through several iterations before they sliced right, but once cura was happy it worked well. one corner curled up during printing, but a heat gun and a lot of cursing got the fan to fit.
the base plate is made of boxes surrounded by very slim wedges and quarter-pyramids for the corners. the screw holes are half cylinders with boxes in between.
the front was originally one solid wedge, but to reduce infill the wedges were reduced to were the screwholes are and the front is just a box. this was a real pain before I knew tinkercads "workplane" feature
detail of combined pieces for the base plate front and sides
*** not a fan: hexagons, airflow and structural integrity ***
looking for grills i got hung up on "honeycomb" patterns and tinkercad had multiple tiled hexagon (or polygon) shape generators.
the biggest problem was fitting the hexagons to the (modeled) 120mm fan. after multiple failures i found a combination of radius, spacing and offset that was only slightly imbalanced, and put the thicker connections lengthwise.
to have space for screw holes (and because they were outside the fans diameter) the corner hexagons were manually cut out before inverting the hexagons into holes.
(the transparent yellow squares were just a placeholder for the 120x25mm fans)
hexagon fan grilles and fan mounting holes
*** the tipping point: legs, feet and stabillity ***
the legs went through several ideas and revisions. I liked the open "beam" leg design by summerside guy https://www.thingiverse.com/thing:2659909 , but didnt want to mix curved legs with a straight / polygonal baseplate.
Also i wasnt sure how stable and strong such an open design would be. Thankfully they have been super solid.
for the actual design i built a paralelogram (wedge - box - inverted wedge ) and cut out a cross from the center by duplicating and scaling them. the top plate shares its holes with the base plate.
the feet are boxes with quarter pyramids that are clipped (and scaled) to stay within the surrounding wedges.
legs and feet taking shape (left to right). some cutout polygons are slightly oversized because the sloped faces left a super thin plane after combining
*** rebreathing: airflow issues and exhaust vanes (experimental) ***
this design helps, but does not completely solve air-recycling issures, to be improved
originally I had a piece of ducttape to seperate the front intake and rear exhaust, but after seeing a youtube video using incense to analyze airflow i realized the exhaust air went all the way to the floor and back to the intake, so I needed to redirect the exhaust far away from the intake.
I had a polygonal duct in mind (more wedges and pyramids, yay) but the output area was less than half of the fans area and reading about corners, bends and turning vanes (little redirection fins to reduce turbulence) I realized something round would be needed.
The model is quite simple, a cut of plate with screw & fan holes and 3 hollow half cylinders, cut to 45° wedges, stacked and clipped so they clear the legs.
I didnt want to have 3 parts between the rear screws and the fan, so I left some super thin tabs to slide under the rear legs.