Yeah, so I started over. Now I'm tying components together with rigid joints and tying them to points on sketches whose measurements use parameters. This is the measurement I tweaked that blew my model up last time...
Maybe I should hashtag this thread. #Fusion360 #MCAD
Wheee! Look at me! I figured out how to get two hinges and a door to move in sync. (Revolute joints for each hinge pin, rigid joints between the pieces, then let F360 figure out the rest.) Anyway, the LACK printer enclosure continues slowly.
As promised, there's just a little #gridfinity storage under the lid.
It's about time to stop pushing pixels and start melting filament. I think this is at least a week of print time and about three Kg of PETG, if I get everything right on the first try. Which I won't.
@3dprinting This is part of the top rail where the Gridfinity bins go.
The two rail pieces are held together by dowel pins, and they are tight and rigid. I made the grid floor a separate insert because I couldn't get a good surface finish when it was printed upside down. (And now it's a contrasting color.) The grid floor is also two pieces joined by dowel pins.
The rest of this rail is on the printer now.
@3dprinting The bottom of the slot between the rails is 0.2mm wider than the top, so the gridfinity tray snaps into place and isn't coming out. (I can push it out from the bottom.) I tried 0.8mm on the first iteration, but I couldn't force the tray in.
@3dprinting The purple piece is the end cap for the LED channel. It press fits into place. The wires will feed into the channel from the other end. This will probably be one of the trickier bits to assemble when sliding this down onto all four legs at once.
The filament is Prusament Ultramarine Transparent PETG. The other colors are Prusament Prusa Orange and Prusament Matte Black. The ultramarine is outside the gamut of most LCD screens.
@3dprinting The orange post on top is not a separate piece. I did a layer height color change.
@3dprinting Here's the other end of the LED channel. It's open on the bottom for wires. I can drill a hole through the table anywhere that is hidden by the square plate and doesn't interfere with the screw holes. I think I'm using JST SM connectors, so the hole needs to be that big.
This is by far the most complex mechanical assembly I've ever designed.
@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/ )
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/
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 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/
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.
@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/∞
@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
Kernel Bob 
Gavin Campbell
PlantagoLabs