FLsun SR invisible enclosure

This enclosure provides effective isolation for heat, noise, nasty fumes, and dust, while preserving the minimalist look of the printer, and the 360° view on the printing process.

Prerequisites

A number of changes are required to allow the printer to be enclosed in this way:

• Limiting the usable printing area to an equilateral triangle with an inscribed circle radius lesser than 85mm (and not doing auto-leveling), to prevent the parallel arms from hitting the acrylic panels. But the panels are easy to remove for larger prints and for auto-leveling (just loosen the top corners' screws). Beware that when homing from some positions inside this reduced area the effector can move beyond and cause collisions, so the end gcode should do an abolute move to X0 Y0 before homing ! (Now I know that my 3mm acrylic panels are somewhat forgiving)
• Moving the extruder so that it is included in the printer's boundaries: this mounting option achieves that, and allows you to enclose the spool too
• Moving the printer's display out of the extrusion slot, which I did with an adhesive mount
• Rerouting the electric cable between the bottom and top cases. The simplest option would be to drill a hole on the side of the printer's top (similar to the existing one on the bottom). I took the more complex way and put the wires through the aluminium extrusion, in a compartment at the extrusion's back (not the center compartment in which the linear rail is bolted, but one next to it). This requires more work as the column must be disassembled to drill the extrusion with a drill press, and it has to be cleaned thoroughly from any aluminium chips which could find their way to the linear rail… I also had to replace the wires, which were too short (since the connector cannot be kept).

Components

The enclosure is made of three identical acrylic panels of dimensions 328x688mm, 3mm thick. One of them is hinged, I made the other two fixed. The panels do not require any further cutting or drilling.

The panels' edges almost touch the extrusion's slots (with a 1mm gap on each side), making the edges almost invisible. Each panel is secured by four 3d printed corners which are screwed in the extrusion slots with plastic screws and custom sliding nuts. The corners have some play to allow for thermal expansion (and the top corners are screwed slightly higher for the same reason). The door has four hinges instead, which use a short length of 1.5mm nail as axle. The corner hinges are bolted in the extrusion slot, while the intermediate ones are just slid, which is OK since they don't hold any load but are only here to keep the door's edge straight. The moving halves of hinges are glued on the acrylic panel. Symmetric handles are fixed with double sided tape on the door's remaining corners.

Adhesive foam tape makes the joint between the frame and the acrylic panels airtight. I used 2mm thick, 5mm wide tape for the sides, (at a 2mm distance from the edge) for the sides, and 6mm thick (actually, twice 3mm thick), 6mm wide tape for the top and bottom (at a 0.2mm distance from the edge).

An army of small magnets (3mm diameter, 0.8mm height) ensure a continuous contact of the foam tape joint which improves noise isolation (for the top and bottom, stronger or more numerous magnets would be needed). These magnets also keep the door closed. For the sides I used pairs of facing magnets separated by a tiny gap: one glued on the acrylic panel's through a spacer, one on a 3d printed clip which slides into the extrusion slot. The absence of direct contact avoids transmitting the vibrations from the linear rails to the acrylic panels. For a the top and bottom, a single magnet is attracted by the steel case.

Building

The main cost if the price of three acrylic panels (which I ordered laser-cut from a local shop). I printed everything in PLA, but PETG or ABS could be used if heat is an issue (I don't expect this will be the case). The corner, corner hinge, and handle parts should also be printed mirrored.

I'm pleased with the result, the noise reduction is significant, and ABS printing is now much easier !

Reducing print area

To avoid collisions, I reduced my print area to an equilateral triangle with an 82mm inscribed circle radius, which corresponds to the area between the pillar's inner edges, and leaves 5mm clearance w.r.t. the panels. I did this in Cura, by adding

machine_disallowed_areas = [[[-130, 82], [130, 82], [130, 130], [-130, 130]], [[130, 61.1666], [19.6299, -130], [130, -130]], [[-130, 61.1666], [-19.6299, -130], [-130, -130]]]

in the [values] section of $HOME/.local/share/cura/4.11/definition_changes/FlSun+SuperRacer_settings.
inst.cfg. I also added

G0 X0 Y0

to the end gcode, before homing (G28), and after switching back to absolute positioning (G90). This prevents collisions when homing, which would otherwise happen when the last position is along an edge, close to a corner.

A safer solution would be to let the firmware know about the reduce build space, and/or, add physical endstops to the effector to detect collisions and do an emergency stop if it ever happens.

Finally, I take care to remove all panels every time I need to do a bed auto-leveling (this could be avoided by changing the firmware).