

The whole reason I had to open mine up is that water got inside, and I don’t even use it in the shower. I think they removed the screw to either cut costs or make it more difficult to repair.


The whole reason I had to open mine up is that water got inside, and I don’t even use it in the shower. I think they removed the screw to either cut costs or make it more difficult to repair.


My previous one (an older model, which had a screw in the bottom) lasted a long time. This newer “sealed” one got water inside within 2-3 years and had no screw. Fortunately it seems that opening it up and cleaning the circuit board helped.


Interestingly, the supports could even dissolve in the main liquid ingredient of the original resin, like a cube of ice in water. This means that the material used to print structural supports could be continuously recycled: Once a printed structure’s supporting material dissolves, that mixture can be blended directly back into fresh resin and used to print the next set of parts — along with their dissolvable supports.
Unless I’m reading this too optimistically, it seems like recovering the resin just requires adding more of the original solvent, which sounds pretty good (as long as that solvent isn’t much nastier than a regular resin solvent).


My quick and dirty math based on some captions of the figures from the paper suggest it’s unlikely they’re getting amplification for now, because it seems like the even the “low” resistance state is quite resistive. But I still suspect it can be done, and they do characterize their structures as “active” - thanks!


Well, a logic gate doesn’t fundamentally have to amplify… if the control current exceeds the output, it isn’t amplifying but fill performs logic. I am too lazy to look myself, but did they demonstrate amplification? If not, I think it’s doable.


Couldn’t you build an amplifier by using a thin wire that heats up a larger wire? If you size the large wire to minimize self heating, then a small current would cause the thin wire to act as a heater, switching the large current.
For what it’s worth, it’s the same with Prusa. The only work I do on my printer is glue stick on the PEI sheet when printing otherwise-incompatible materials.


Well said. It’s just important that when recommending printer models to newcomers that we’re honest about time vs money and printer vs printing.


In practice, I haven’t found the print volume of my MK4 to be too limiting. Occasionally more X/Y would be nice, but plenty of parts that are too big for my printer would be too big for any printer and still need to be cut. The other issue is that even fast 3d printers are slow and I don’t really print things that take entire days. Even printing dactyl keyboard halves takes hours thanks to the need for supports, so I can’t imagine someone frequently doing really huge prints (particularly in height).


I had the same experience the one time I tried it. It seemed like it might be trying to do a “ramming” sequence like used on the XL, but it just jammed my extruder. I haven’t tried it again. If you have the time and motivation, it’d be great to submit a bug report to Prusa.


Interesting, it took me a while looking at your images to figure out why the original design didn’t work. The problem was that there was no solution that could avoid at least one extremely long bridge, and that bridge also forced the adjacent bridges to be “wrong” (though maybe if it printed the super long bridges first, it could’ve made the rest short).
I don’t have much to add besides being surprised the problem was more interesting than it first seemed…and I don’t accept that you were being an idiot because it want immediately obvious to me either. Or I am one too :)


especially if it were printed vertically, i.e. you would be pulling the final product into your extruder in such a way that it would be pulling against the layer lines.
I agree that vertically-printed filament would have poor tensile strength, but isn’t most of the load from the extruder going to be compression, shoving it from the extruded gear to the melt zone and nozzle? Other than during retractions, doesn’t the tensile stress just comes from pulling the filament off the spool?


What about printing it in two halves the each have a flat bottom? Since the optical quality doesn’t matter, the line down the middle of the lens won’t matter.
I think the Jerusalem Declaration on Antisemitism is much better, and allows for legitimate discourse on apartheid, genocide, et cetera. I actually learned about it on Lemmy!


Fortunately it looks like the federal courts don’t allow this any more: https://www.ussc.gov/about/news/press-releases/april-17-2024
But of course the state courts have their own separate rules.


It was sold in the gift shop, not on display. I know it’s not an enormous difference, but let’s try our best to keep the misinformation just on their side.


Sure. And you can import them too if you’d prefer.


Do I just connect thermal pads to the ground plane and call it a day?
Yup.
Wouldn’t that make the components hard to solder with hot air?
Sorry, I’ve never tried hot air assembly.
Do I make an isolated polygon that only acts as a thermal pad?
Ideally the copper area is big to spread out the heat. If you have an isolated polygon it can’t spread very far and buys you less cooling.


The 7333A is a linear regulator, which means it drops voltage by converting power to heat. Typically those make sense when the input voltage is close to the output voltage or the load is very small. If it’s getting too hot, the load is high enough that the efficiency will be very bad…whether or not this is a problem depends on your application.
Some random site claims 170mA and another claims up to 400mA. 170mA * 8.7V (12V in minus 3.3V out) = about 1.5 watts, which is too much for a TO-92 package.
Can you use a tiny buck converter instead? Or a larger package for the linear regulator that can add a small heat sink?
As for your actual circuit, the second transistor is an interesting idea (you’re using it to invert the state so you can have the GPIO pulled in the non-problematic direction?) and I don’t have enough experience to give further suggestions.
Correct: newer models have no screw.