HewlettHackard @ HewlettHackard @lemmy.ca

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51

Joined

2 yr. ago

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!

https://jerusalemdeclaration.org/

https://m.youtube.com/watch?v=5YGc4zOqozo

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.

This looks great! I’m super happy with my MK4, and have never had to do anything with it after the initial kit build and re-seating the LCD cable to fix some early screen-blanking issues.

I’ll probably skip this for my own printer since it seems like most (but not all) of the speed up comes from layer height, but $99 is not terrible for anyone who gets value from it. And anyone buying a new printer gets this stuff with no price increase, which is nice and makes the MK4/MK4S even easier to recommend.

I didn’t know how much more dimensionally accurate Prusa’s prints are compared to the competition, but it makes sense now why there are so many calibration models online if that just isn’t the way every printer works. I’ve designed some parts that need an 0.1mm first layer because I’ve never had any failures with that, but I guess if I share the STLs other people might have trouble.

They definitely don’t know what they’re doing. They featured this one, which is a death trap. It has a disclaimer that it might not be safe above 120V, but it’s absolutely unsafe and a code violation in the US, where we use 120V (and are very litigious). The disclaimer says they’re trying to get it approved which implies they believe it could be and that the design is sound, but fundamentally it cannot meet code in the US for mains voltage use.

Even if the design were sound, there are material requirements, and having seen the quality of prints some people find acceptable, there’s no chance allowing random people online to print their own boxes is safe.

I think they basically run the contests and feature things based on “ooh this is neat” and “this will excite people to use 3d printers”. It’s a marketing thing, and I guess I accept it because I have low expectations of even pretty-good businesses. But if it’s illegal…someone should probably let them know.

I haven’t bought used myself, but based on my own experiences with my printer (MK4; I love it) I don’t think there’s a ton to worry about buying a used quality printer. I would not buy a used low-end printer because the odds are much higher that the seller found it frustrating.

A used Prusa MK3S is probably an excellent choice if a Prusa MK4 kit is out of your budget and a Bambu printer is out of your budget or doesn’t meet your other requirements. The seller probably either realized they don’t actually print often, or upgraded to a MK4 (or XL if they had the budget). While you can upgrade a MK3S to MK4 with Prusa’s upgrade kit, the cost of the kit is so close to just buying an MK4 that it’s not worth doing (and Prusa admits this; they only offer it because of the flak they got for not doing such a kit in the past). The MK3.5 or 3.9 upgrade kits could make sense for some people…but in many cases someone looking to upgrade would likely leave the MK3S untouched and just buy an MK4.

Do you want the printer to be a tool, or a hobby (i.e. you don’t mind fiddling with the printer itself to improve the results, you don’t mind spending more to upgrade components, etc)?

If the printer itself is a hobby you can go cheap, but if you want something reliable you don’t have to mess with or upgrade, I’d suggest getting something as nice as you can afford, maybe a Prusa mini or Bambu A1 mini if you don’t care about open source. Also consider something like a used Prusa Mk3.x.

You’re affecting the hardness of the metals if you’re heating them to glowing point, because you’re heat treating them. The actual consequence is probably minimal, but you could potentially be softening the brass tip which could affect the rate of wear. From skimming a few random online sources, brass is only work-hardened, so if the nozzle was previously hardened, you’re un-hardening it (apparently quenching from high heat only hardens ferrous metals like iron and steel?).

I was expecting Hal