3D Printer Enclosure... Almost entirely from scrap!

    Most people intuitively grasp why people put plants in greenhouses, but the average non-3d printer may not even consider doing something similar to a 3d printer, let alone understand why it is worthwhile.

    Why build an enclosure:

    3D printers basically melt plastic, squeeze it through a nozzle, and lay one layer at a time and stack those layers atop one another. However, while the heating up is covered by the extruder or "hot end", the cooling down is heavily impacted by ambient temperatures, and this is a concern because cooling plays a critical role in:

    • Adhesion to the bed - From this, all dimensions are defined. If your model comes loose, there's no way you'll get a successful print. Too cold, and your first layer may not stick to the bed.
    • Layer adhesion - a layer that cools too quickly won't stick to the layer below very well (or at all).
    • The avoidance of aesthetic defects such as stringing. If temps are too high, when the extruder stops pushing hot plastic through, instead of breaking, the filament will stretch out into stringy fibres and even connect points that should only have empty space between them... like this:
    A rather serious case of stringing.

    Printing is best done in a room that's around 22oC. Colder temperatures are problematic. Similarly, dusty environments can be very bad for 3D printers, so building an enclosure that can be heated by the printer itself, with the added benefit of keeping dust out is often a good idea.

    Now there are thousands of different designs for 3D printer enclosure. The most popular involves one, two (or more) modified $12 Ikea "Lack" tables, add some 3D printed hinges and spaces, with some perspex or polycarbonate sheets for windows, and you've got yourself a cheap, functional, and reasonably pretty enclosure. There are literally dozens of variants that you can find online, but here's one example:

    A nice 2.5 Lack table based enclosure that I found online.

    Unfortunately, I can't keep the printer inside the house due the fact that we're running out of space, our cats sometimes "spray" the printer with their personal scents, and other times, they get a little too close to the hot stuff for my liking. So an enclosure in the garage was the only choice.

    I wanted to build something like a Lack table enclosure, but when I found out how appallingly breakable, hollow, etc these tables costing the princely sum of $12 really were (I shouldn't have been surprised), I knew I wasn't going to be content with that. Also, since the garage is also my primary workshop, the potential of wood flying across the garage (doesn't happen very often, but it's a concern when I'm teaching newbies how to use power tools), I wanted something significantly stronger, shock resistant, and a little roomier inside.

    Hence my latest scrap wood challenge....

     

    The cabinet during assembly. You can see the internal cross beams, but nothing on the outside of the windows. The wood under the clamps was simply scrap used to hold the windows in while the glue dried.

    The corner posts aren't actually posts, but scrap plywood glued together, then shaped. 73 pieces of 17mm scrap plywood were used. I then sanded it down, added adjustable shelving holes into each post, and pocket screwed the internal tapered cross beams that would make up the inside frames of my windows. I then spray painted it (which in Canberra winter takes forever to dry), lightly sanding between layers, then spraying again until an even coat was achieved. I then cut up some excess bench top from another project.

    The bench top (here the top and bottom of the cabinet) was exceedingly prone to cupping. I left the cut pieces unvarnished for about a week, and the middle of each piece was roughly 1.2-2.8cm higher than the edges. So I slowly (and incrementally) pressed the boards flat under about 15 clamps over the space of about three weeks, then sealed up the convex side with varnish. This allowed the moisture to slowly seep into the concave side, which expanded and straightened the piece. Once it was flat again, I sealed the underside, with multiple coats and light sanding between layers to get a nice semi-gloss finish.

    I then pocket screwed and glued the bench pieces to the cross beams, put the windows in place, cut some tapered/compound edged pieces for the outer window frames, and screwed them together. I also did something similar to make the door as well. Unfortunately, I forgot to tighten the fence on my router table, and managed to take a chunk out of the corner of my door, but it was a purely aesthetic blemish, so I just left the door as it was. Once the door was finished (albeit imperfectly) I installed it with a continuous hinge, and two magnetic clips at the top and bottom of the opposing edge.

    I learned the hard way that the screws supplied with hinges and clips are often made of very soft metal. It's essential that you pre-drill your holes and I'd even recommend using a perfectly-sized screwdriver over a drill or impact driver to drive them in to avoid stripping the screw.

    I put some 45mm x 90mm wood "struts" underneath the cabinet floor along the side and back edges to attach height adjustable feet, and I decided to put a drawer in underneath with some drawer runners, handle and additional ply wood I had laying about.

    For safety, I did buy a smoke detector and installed it inside the cabinet. I also bought some self-adhesive LED lights to illuminate the printer from the enclosure's ceiling.

    Here we have the cabinet, with lights off, and lights on. I've placed my adjustable shelf inside, sat the printer, web cam and dehumidifier on top. There's actually a gap between the back window and the adjustable shelf to run cables. The bottom half of the enclosure stores the power board, filament, and my Raspberry pi that runs OctoPrint. If I get a larger printer, I can swap it out with the current printer. Alternatively, if I get a second, similarly sized printer, I can put both in this enclosure. The drawer stores my manual, assembly instructions, spare nozzles, lubricant, spare heat bed sheets, maintenance tools, keyboard and mouse for the Pi.

    The windows are made with 3mm polycarbonate sheets. The sheets are considerably stronger than perspex, and far more impact resistant than glass. Each panel was epoxy glued, then screwed to the frame in at least 20 locations. Unfortunately, I had to buy a piece of polycarb for the door as I used all my suitably-sized scrap on the windows. You'll notice that the drawer handle is identical to my planer trolley chest of drawers. They come in packs of two, and my planer trolley only has 3 drawers.

    You might be looking at this and ask: "Why didn't you sand out the saw blade marks on the edge of the bench top pieces?" There's two parts to that...

    1. I forgot to do that before I attached the pieces to the posts and cross beams that were already painted.
    2. I don't actually mind it, after all, this was largely thrown together with bits that were intended for other projects... or the bin.

    As a completely incidental side note....

    The table this cabinet sits on was made 20 years ago when I lived in a tiny college room. I got the pieces cut at the local hardware store, then built it with nothing but some screws, a screwdriver, some L brackets, a chisel, and a hammer. I've since reinforced the original frame, and sanded the plywood top down after years of neglect, and re-coated it with an oil finish. I'm honestly surprised how resilient the little rough-hewn table has been, especially considering that it has been flood damaged, routinely urinated on by invading possums, gnawed on by rats, soaked in beverages by drunken university students, used as an improvised scaffold, and many other events that would have utterly destroyed your usual Ikea-grade furniture.

    Which is why I have certainly spent more on polycarbonate, lighting, and screws in this enclosure project than two Ikea "Lack" coffee tables would have been, but I've recycled a bunch of wood, used up a lot of half-used paint cans, added some nice drawer based storage, used up some adjustable feet, handles, drawer slides, 3 sheets of polycarbonate, magnetic clips and hinge that had been sitting around for ages, and really cleaned up my scrap box, wood trolley, and workshop overall in the process.

    Was it a much more involved process? Yes!

    Was it frustrating and slow going? Absolutely!

    But I finally got this finished, and I'm proud of the result.

    Where to from here?

    1. I need to build a better mount for the web cam.
    2. I'd like to put the Raspberry Pi in some sort of case.
    3. I will move the printer's power supply out of the cabinet so I can keep it cooler and stop it from going to an early grave.
    4. I'd like to wire the Raspberry Pi to a relay and configure it so it can cut the power to the printer if it starts to malfunction.
    5. I'll probably put the entire enclosure onto it's own safety switch, as an additional precaution.
    6. I need to 3D print a plug to seal the hole that the power cord comes in through to prevent dust and spiders getting in.

    Always more to do. But I hope you find this interesting. Stay safe and happy tinkering!

    Ham.


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