Kernel Bob 
@3dprinting The hinges have bar magnets to hold them closed. That's from Prusa's design, but I moved them to give them about 60% more mechanical advantage and increase the closing force. They feel very satisfying to operate, but I won't know for sure until the doors are attached.
@3dprinting I suspect most of you, like me, get to see the insides of IKEA furniture far too rarely. So here's a LACK table undergoing surgery.
Now I'm trying to excavate out to the corner to find out how much wood is there for the legs. I want to run a cable in next to the leg and hide it inside...
@3dprinting Calling it wood was far too generous. As I expected, there's a block of sawdust-glue porridge in the corner just slightly bigger than the leg. It's hard to measure in there, but it looks like it extends about 60mm from each table edge. When I drill the hole for the cable, I can get a better measurement.
@3dprinting Now that we know where the solid parts are inside the table, we see that most of the screws in Prusa's enclosure design are screwed into air. Hmmm...
(Source: https://blog.prusa3d.com/mmu2s-printer-enclosure_30215/ )
Prusa Printer Enclosure V2 - with MMU2S support - Original Prusa 3D Printers
Our first 3D printer enclosure became incredibly popular - and naturally, once we released our new Multi Material Upgrade 2.0 and 2S, people started asking us for an updated enclosure that would accomodate the Original Prusa i3 MK3S (and 2.5S) 3D printer...
@3dprinting I redrew the prop arm to move the bracket to the corner of the table. Numerous picky little changes later...
@3dprinting This joint locks two PETG pieces together far better than it has any right to. I had to force the pieces together with Knipexes.
I'm printing the prop arm (previous toot) in two interlocking pieces. Prusa's design used a very loose mortise and tenon with Superglue.
@3dprinting Here's the new prop arm and the tool that squeezed it together. The pieces aligned pretty straight but not perfect.
Note that the two halves of the arm were printed in different orientations. I had to print the left half with support.
@3dprinting I've solved the problem of mounting LEDs to the underside of the LACK table in my printer enclosure. I'm very happy with the result.
@3dprinting ??? This was supposed to be a video. It looks like I just uploaded a still.
@3dprinting I am still working on the printer enclosure when I'm not traveling. Today I made a test piece that slides along an IKEA LACK leg. I put steel dowel pins on two sides for a tight but low-friction fit. It works better than expected.
@3dprinting I plan to put the printer's power supply outside the enclosure attached to one table leg. The bottom of the power supply will fit into a cradle, and a cap will slide down over the top of the PS to keep it stable. To remove, I'll just slide the top up and lift the PS out.
@3dprinting It took the entire day, like 12 hours, just to model this power supply cover. It doesn't look that hard, but it took a long time to collapse the infinite possibilities down to this one. It's on the printer now; I'll see if it fits in an hour.
@3dprinting I adjusted a few dimensions, and the second try fits nicely. There's just barely room enough (I hope) to bend the wires around and connect them into the jack.
This is the same receptacle Prusa uses for their enclosure's optional quick release. So if I ever move my printer into one of those, it will be ready to plug in. https://www.prusa3d.com/en/product/psu-cable-quick-release-for-original-prusa-enclosure-mk4/
PSU Cable Quick-release for Original Prusa Enclosure (MK4) | Original Prusa 3D printers directly from Josef Prusa
A quick-release connector for the 3D printer’s PSU cables. This is an ideal solution for everyone who often takes the printer out of the enclosure. This spare part is compatible only with the Original Prusa Enclosure.
@3dprinting Here's the power supply mount I came up with. The upper bracket slides up, and the power supply can be removed without tools. That way I can take the printer to the bench without a lot of hassle.
The AMP MATE-N-LOK connector is rated for 70 amps! The power supply is rated for 10.
@3dprinting It will go outside the enclosure on the back side, as shown here.
@3dprinting The cable passes through the foot under the leg to another MATE-N-LOK connector inside the enclosure.
You can see ribs on the upper bracket. Those house the dowel pins I'm using as bushings for the slider. I posted photos of the prototype of that upthread on May 9th.
@3dprinting Unrelated, but also visible in the first photo above, the purple ("aquamarine") hexagonal tube in the lower left is for the LED wiring. The LED power supply will be underneath, and one strip of LEDs will be in the enclosure lid. Power and signal will run through that tube and up through the leg to the lid.
@3dprinting Stupid Fastener Tricks, Episode 87.
These dowel pins I got on Amazon have internal threads. I had no idea why, but I got 'em anyway. Turns out they're pretty useful for inserting/removing them into deep holes and making 100% hidden hinge pins.
@3dprinting I have finally started assembling the Black LACK Stack Hack (printer enclosure). I am nothing if not slow^Wdeliberate.
I found out that the "plugs" that go between the hex nuts and the table corners (the red parts) are too tight to slide over the threaded rods. I tried forcing one on with the flywheel wrench, but that got old. So I'm printing new plugs now.
(The flywheel wrench works very well.)
@3dprinting Here's the next layer. At this point, I should stop and do some more design. I want to attach several things to the underside of the next table, and I'm not sure they'll all fit. Nor how to attach them.
- a rackmount power distribution unit in back
- steel sheet storage in front
- a Gridfinity shelf in front
- LED power supply and cabling
- Raspberry Pi or mini PC for Octoprint
@3dprinting Stupid Fastener Tricks, Episode 88.
To hide the screws on the power distribution unit, I printed some plastic covers that are held in place with magnets.
This brings the total magnet count in this enclosure to 120, I think. If I put a shelf of Gridfinity slots in front, that'll be another 48 magnets.
@3dprinting One more layer. This is the surface the printer will sit upon.
This is by far the most rigid IKEA furniture I've ever handled. So that validates the steel rod idea.
But the back right rod is not parallel to the others now. I must have torqued it somehow. The rest of the assembly seems square. Not worrying yet.
@3dprinting After all the progress I've made on the Black Lack Stack Hack recently, I was due for a setback. I carelessly picked this assembly up by one end to show it to someone, and it cracked under its own weight. When it hit the floor, the opposite joint cracked too.
They were wobbly anyway, so I should design something better.
Edit: two more photos.
@3dprinting I spent yesterday designing a new joint. I ended up using a bigger mortise/tenon plus three dowel pins. (I really love dowel pins.) The pins are 5x50mm and 3x30mm. The screw is M3x10.
I printed these two test pieces to verify fit. They are plenty rigid, and I have to pry them apart with a screwdriver. This is definitely overengineered. (I really love overengineering things.)
@3dprinting The bad news is that the two parts that broke are the two longest-printing parts in the whole enclosure. Reprinting all three parts is about 15 hours. Fortunately, I started last night...
@3dprinting One more layer. The cord at the back left is for the addressible LED strip in the lid. It was a pain to fish through. It is a power cord with the ends snipped off; I'll crimp on some JST SL connectors later.
I've been looking at the CAD drawing for so long that it doesn't even look like a new thing.
@3dprinting One more layer. I test fit one door and one window. Each door is held on by 4 magnets and has another four keeping it closed. Each window is held on by 8. The windows have just the right amount of magnetic glomp (technical term). The door is kind of wobbly but it stays closed.
I have errands for the rest of the day, so the lid will have to wait.
@3dprinting I think if I wanted to improve the door action, I'd make it so the closure magnets are further apart. They are too strong, so the door slams.
@3dprinting I amuse myself.
The precut acrylic pieces came with holes for door handles, but I didn't like the handles they suggested. So I made these.
Note that there's still no printer in this alleged printer enclosure.
@3dprinting I put the eyes on long, thin stalks and added a machine screw for weight. Hopefully, when the printer starts the cabinet vibrating, they eyes will jiggle. We'll see.
@3dprinting I'm working on the LED strip power supply for my printer enclosure.
I've been pondering the layout of these parts for a while. Last night I got the power entry units, and I spent the whole day today coming up with this. It's nowhere near done, but it shows the general layout. I'll split the blue part into two halves suitable for printing somehow.
I should have bought a power supply with a power plug integrated.
@3dprinting Yeah, so, the Feather SCORPIO. It's based on a RP2040, and it has eight 5V outputs for driving addressable LEDs. I only have 195 LEDs, but it makes the wiring easier to have three short strips instead of one daisy chained strip.
I'm putting in four JST connectors in case I want MOAR LEDS!!!! later.
@3dprinting Here's what I came up with. First picture shows the bottom half with components attached. Second pic is the top half.
I just started printing it; I'll see what doesn't fit.
I'm grateful that Adafruit publishes CAD models of their boards.
@3dprinting I put in a partition to isolate the 120V power from the low voltage stuff. It's not a perfect seal, but it'll probably keep my fingers safe.
@3dprinting I printed three iterations of the bottom half yesterday and one of the top half. Today I spent a solid 16 hours in Fusion360 tweaking the design -- why is F360 so tedious and manual? Every time I changed anything at all, I had to redo the flanges where the case halves meet.
This should be pretty close to finished, so I'm using the good filament.
@3dprinting Everything fits perfectly. The top half is printing now.
(Yes, that's a 3D printed stand-in for the controller board. Adafruit published an STL. It has 0402 components, and they came out more 0402-shaped than blob-shaped. But the connectors cracked when I removed the supports.)
I'm running out of ways to procrastinate crimping the cables. I do not enjoy crimping.
@3dprinting The next challenge was attaching leads to the LED strips. I glued this 144/meter RGBW strip into this aluminum channel. I'd printed end caps with embedded magnets (the aquamarine parts). I'd drilled holes through the table to run the leads down to the power supply (previous post). But the solder tabs on the strip are tiny, and I'd made no provision for strain relief.
This is what I came up with. I've assembled one, and it seems to be okay.
@3dprinting The cable tie will be inside the hole in the table when this is in place. There's room, because this assembly is smaller than the connector on the cable end.
I printed tall jaws for the StickVise to hold the aluminum channel, of course.
@3dprinting This strip will run vertically up the left side of the cabinet. Another will run up the right side and will be just the same. I don't know what I'm going to do for the strip across the ceiling, because there's no room on either end for anything. I'd assumed I'd run the leads straight up somehow, didn't really start thinking about how to attach the leads until yesterday. I've got 1.5 or 2 mm of space on each end, I think.
@3dprinting I never posted photos of the LED power supply after wiring. Here are some photos of the LED power supply after wiring.
Everything unplugs or unscrews except the wires on the power inlet module.
@3dprinting And here it is with the lid on. It looks remarkably unremarkable, just another power supply thing.
@3dprinting The LED controller and light bars are installed into the enclosure. FInally. Hooray!
I am very pleased with the way they came out, though I worry that the top bar is fragile. There's no strain relief on the cable; it's just hanging on by its solder joints.
I might tack the wires up to the underside of the table later, but for now, they're staying in place just by their own stiffness.
@3dprinting Here's a test pattern, viewed from the back. From the front and sides, you can't see the LEDs directly.
@3dprinting That test pattern uses golden ratio colors to generate apparently random but pleasing color sequences. It's a pretty cool technique which I just re-learned about. This 'blog post describes it pretty well.
https://martin.ankerl.com/2009/12/09/how-to-create-random-colors-programmatically/
How to Generate Random Colors Programmatically
Creating random colors is actually more difficult than it seems. The randomness itself is easy, but aesthetically pleasing randomness is more difficult. For a little project at work I needed to automatically generate multiple background colors with the following properties: Text over the colored background should be easily readable Colors should be very distinct The number of required colors is not initially known Naïve Approach The first and simplest approach is to create random colors by simply using a random number between [0, 256[ for the R, G, B values. I have created a little Ruby script to generate sample...
@3dprinting The LEDs have firmware now. I made a short video that puts them through their paces -- they have modes that match the LEDs on the MK4's front panel, but with more flair. I have no idea how to sync up with the printer's state yet. I'm assuming Octoprint will make that possible somehow.
LED Demo - Black LACK Stack Hack
@3dprinting Yesterday I _finally_ put the printer into the enclosure. After a few hours debugging a badly assembled power connector, it's up and running.
This enclosure is far from finished, but I was having trouble with air currents in my office ruining prints.
@3dprinting I decided it was time to redesign the googly eyes on the printer enclosure. (See upthread at June 19th.)
a) they don't wobble as intended
b) they stick out and get in the way of the door handles
c) they rotate freely in the round holes and the eyebrows are always at weird angles
d) I dropped one of the doors and broke an eye stalk.
🧵 60(?)/∞
This time, the googly is a multi piece assembly that screws tightly onto the door. No wobbling, no protrusion, no rotation.
Note the place to insert an 8mm Allen wrench to hold the eye in alignment during assembly. The eye is held onto the orange bit with double sided Scotch tape.
🧵 61/∞
@3dprinting I'm adding an (Un)original Prusa Drybox to my printer enclosure's lid, along with auto-rewinders. (Thanks to @GavinCampbell for the tip.)
The drybox uses lots of heat set inserts, so I completed a side quest to build an insert press. Now I'm back.
🧵 62/∞
@3dprinting I'm trying to resist the urge to mod the drybox, but I'm putting the drybox on the printer's lid, and the lid tilts past 90°. So I need a way to keep the rails from falling out.
The original is in the first photo; my version is the second.
🧵 63/∞
The autorewinder adapter for the (Un)original Prusa Drybox did not fit. The sleeves that surround the rail are too thick, and they keep the bottom cover from going on.
This isn't an issue for other users; they just let the rails ride higher in their slots. But I screwed my rails down.
So I added a shim under each rail. (It's teal in the photo.) It's temporary; I'll eventually redraw the sleeves so they fit.
🧵 64/∞
@3dprinting Actually, the sleeve thickness is a problem for other people. The rails and therefore the filament spools, up to 5kg, are resting on the bottom panel, putting high stress on the screw holding it up.
🧵 65/∞
@3dprinting The (Un)original Prusa Drybox is installed. I made feet, and the front feet engage little cleats. They're not exactly French cleats, but they're francophone.
🧵 66/∞
@3dprinting The cleats hold the drybox on even when the lid is tilted.
But when I tilted the lid all the way up, just past vertical, the box fell off. So I shouldn't do that. I'd need bigger cleats or a different angle of engagement.
🧵 67/∞
@3dprinting Here are some renders of the foot and cleat. The back feet don't have cleats; they just rest on the lid.
🧵 68/∞
@3dprinting Now that I have an MMU, I am thinking about how to route the PTFE tubes from the drybox to the MMU. My original plan, before I saw how far back the MMU sits, was to route it through the lid. Something like the green line here.
But that wouldn't work. The cable is kinked way too tightly.
🧵 69/∞
@3dprinting Prusa's solution looks like this. Five holes in the back window.
I don't like that because the window is no longer removable without unthreading the tubes. My intention is to make it possible to install/remove the windows while printing or remove the printer and drybox, separately, without tools.
But the routing is much cleaner.
(Photo by Ondřej Stříteský)
🧵 70/∞
@3dprinting So I'm pondering exactly how to do it. If you have ideas, please let me know.
🧵 71/∞
@3dprinting @Siff Maybe something like this? (Very rough draft.) The orange part would slide into the slot in the back panel and be glued in place. The green part would snap in, held by magnets, after the tubes were in place in the grooves at the bottom.
🧵 72/∞
@3dprinting @Siff @esden Here's my idea for passing tubing into the drybox. Once again, the goal is fast easy disassembly so I can remove the printer to the workbench.
(sound on; it's narrated.)
🧵 73/∞
Siff@kbob @3dprinting This looks nice, especially since it minimizes the cutout!
What I was thinking is a simple split of the back in two with magnets to keep the split as rigid as possible (like in the picture). In case embedding the magnets is not an option or they are not strong enough, you can print bars which will have the half circles and the magnets.
@kbob @3dprinting Maybe split the back window horizontally at the holes (or print a two-part separator with slots for the windows) and mount the panes with knurled screws/magnets? This way you can remove the back without tools and without unmounting the PTFE tubes. This might also help with servicing the tubes.
Hope this helps
@Siff @3dprinting Magnets, yeah. You've given me an idea...
Piotr Esden-Tempski@kbob why not make comb style notches at the top of the window? The window is removable and you don't need any complicated mechanics to accomplish that.
@esden I think that would be too high. The tubes have to be low to have the right entry angle to the MMU.
@kbob You can move the holes lower by introducing interlocking fingers from the top to fill the gaps between the “comb" teeth. If this starts becoming flimsy you might need to add some features that keep the fingers from flapping around when you slot them in. Still it might be a relatively simple solution all things considered.
@kbob @3dprinting Heat set insert press in action! 👍
@Siff @3dprinting The even bigger milestone is that I designed inserts into a thing. My previous stance was that captive nuts are superior. But inserts can be placed where nuts can't.
@kbob @3dprinting Before heat set inserts were a thing, I used to heat nuts and embed them in plastic to, essentially, do the same thing. So I’m inclined to use heat inserts where possible. 😀
Captive nuts are great too, especially where the height is limited or the walls are too thin and might get deformed while the inserts are pressed - I had to use a piece of metal as heat sink in such scenario on a recent project.
Gavin Campbell@kbob you will like it. The auto rewinders make it so much easier. The only extra piece I added was a ptfe tube guide for the mmu3. It makes feeding the filament a lot better. Worth it.
https://www.printables.com/model/751530-mmu3-ptfe-tube-guide
@GavinCampbell Yeah, I was having trouble understanding how the auto-rewinders work, so I printed two units: two roller assemblies and three triangular supports. I've been using them standalone on top of the enclosure for about a month. They work great except when they fall off. (-:
I would like to be able to remove the drybox too. Did you publish the model files for your quick release?
@GavinCampbell I haven't figured out how I'm routing the tubes into the enclosure yet. I'm thinking it'll be a hole through the lid, but exact placement and orientation are TBD. I will try to keep it straight enough that I won't need a guide, but if I do, I know where to get one. (-:
@kbob I didn’t post the models. I created them in tinkercad and they were just good enough for me but not polished enough to be something to release. If you are on tinkercad I can share them with you if you want.
For the pass through I did it through the top. You can find passthroughs on printables for that.
I also have mine sitting on legs on top of the enclosure. This allowed me to still open the top if I needed.
@GavinCampbell Okay, thanks. I've got some ideas about how I want to do it, so I'll whip up a model myself.
You're using a Prusa enclosure, and I'm using IKEA tables, so the passthrough will be a little different.
@kbob Oh ya. Ok. That will be a bit different. It was fun creating my setup and works so great. The rewinders always amazed me. Amazing how somebody thought that up.
@GavinCampbell Yeah, I really didn't think the friction of the spool against the hub would be consistent enough. But it works great.
PlantagoLabs@kbob @[email protected] Are those... coffee tables ?
@plantagolabs Yeah. Three IKEA LACK tables in a trench coat.