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Ask HN: Why did consumer 3D printing take so long to be invented?

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Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#151

Post by kragen »

Doxin wrote: post #138
jdietrich wrote: post #66

Earlier quoted context omitted.

The widespread commercial availability of polylactic acid was also a significant factor. It's one of the few plastics that can reliably print on an open-framed printer. The cheap i3 and Ender clones just wouldn't have taken off if we were stuck with ABS.

I think PETG would've also worked. Keep in mind neither of those plastics were rare at the time. The filament form factor was essentially nonexistent though, which makes the whole 3d printing business a lot trickier.

It depends on what you mean by "rare". Both PETG and PLA were commercially available when RepRap started, but they weren't very widely used. PLA's biggest use at the time was reabsorbable medical implants, for example. I don't know what people used PETG for in 02005. I'm not sure either of them existed in the 01970s.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#152

Post by kragen »

fragmede wrote: post #122
kragen wrote: post #65

Earlier quoted context omitted.

It's plausible that our current 3-D printing design workflow has grown up in the computationally intensive way that it did because all that computation was available; it's easier to just use a least-common-denominator but bulky file format like STL than to worry about the incompatibilities that would result from using more expressive files. People have been doing CAD/CAM since the 01950s. Boeing started using CNC in…

Computation for the printer was possible, but home computing definitely was not there enough to let someone model something up in fusion 360 like we think of today. That was the realm of srs workstations like the ones SGI made. I don't think that's a show stopper though. If we had had 3D printers in the 1970's and 1980's, sold at Sears, between the computers and the tools, you'd bring home a paper catalog from the 3d…

I agree that you couldn't have done Fusion 360 on an Apple ][ or a Compaq Deskpro 386. But see https://news.ycombinator.com/item?id=42087099 for my notes on what kind of 3-D graphics you could have done on hobbyist computers of that time period and how we actually did do 2-D CAD on them.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#153

Post by kragen »

foxglacier wrote: post #33
jeffbee wrote: post #23

It was the polymers that needed to be invented. In the 1990s we used to order quick-turn prototype 3D prints for parts to check fit before committing to tooling for hard materials, but we only had 3 days to work with it before it fell apart into a puddle of goo.

I don't think that's a reason. PLA and ABS were invented before the 1990's. What was this self-destructing material, and why?

A surprising number of popular plastics are chemically unstable to one or another extent.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#154

Post by kragen »

stevekemp wrote: post #149
kragen wrote: post #145

Earlier quoted context omitted.

Floating-point was ubiquitous in the BASIC interpreters on early home computers. It was just slow. CP/M didn't really do paging, although you could read and write 128-byte records to disk. But CP/M disks were typically only 90 kibibytes, or maybe up to a mebibyte for 8-inch floppies. And a lot of hobbyist home computers omitted disk drives because they were too expensive.

Sure floating point is possible, but if you're thinking of something like a 6502 or Z80 you'd have to implement it yourself - no maths co-processor, or dedicated instructions for it. In terms of paging I was thinking of paging in later layers of data from disk, perhaps from a large file, perhaps from a series of files. But CP/M certainly did have support for paging RAM, in 3.x, if your hardware supported it. (My own…

Yeah, people did do overlays a lot on CP/M.

If you were using a 6502 or Z80 in the late 70s you wouldn't have to write the floating-point routines; you could just call the ones in the BASIC interpreter you probably had in ROM. They'd still be slow.

As for paging RAM, do you mean bank switching? The 8085 and Z80 didn't have MMUs, so you couldn't do "paging" in the sense people normally understand it today.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#155

Post by kragen »

vel0city wrote: post #139
Novosell wrote: post #135

Earlier quoted context omitted.

Why are you giving your numbers leading 0s?

It's to showcase their superior thinking over four digit year neanderthals. A very iamverysmart thing, as if people don't know after the year 9999 there will be a 10000. Which is why I'll always prepend even more digits when replying, because I'm thinking even further ahead than the short-sighted five digit people and even bigger numbers all the time. https://longnow.org/

HN comments are not the right place for personal attacks, and especially not personal attacks for being too nerdy.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#156

Post by numpad0 »

jdietrich wrote: post #66
sottol wrote: post #25

I think it's probably correct that few people *really* cared until the Reprap project showed a real DIY 3D printer was possible. Early machines were industrial machines with huge price tags, proper linear motion systems, complicated extrusion systems and so on. There is a bit of a mental leap to go from seeing $100k+ machine and dreaming to design something that can be built for $200-500. The problems were: no "refer…

The widespread commercial availability of polylactic acid was also a significant factor. It's one of the few plastics that can reliably print on an open-framed printer. The cheap i3 and Ender clones just wouldn't have taken off if we were stuck with ABS.

IIUC, airsoft "biodegradable" bullets were always PLA. They were bought in killos and expended in hours.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#157

Post by simne »

kragen wrote: post #143
simne wrote: post #134

Earlier quoted context omitted.

Just for info, Centronics interface is very slow for 3D printer. It could work (as 2D plotters work), but people make figures faster, and 3D made things even worse.

3-D printers are much lower bandwidth than conventional 2-D printers, and the conventional Centronics parallel port could handle up to "75,000 characters per second", according to https://en.wikipedia.org/wiki/Parallel_port#Centronics . The total amount of data in a print is larger, but typically the 3-D printer is only processing 1–10 commands per second, compared to about 100 for a dot-matrix printer. But the point…

3D FDM printers need much higher bandwidth, because their controller need to make PWM for motors control, and for other things.

Yes, one could make 3D printer without PWM, but it will be extremely slow, or even cannot do some things.

With modern microcontrollers this problem resolved by using interface just for high level commands (all low level control performed by microcontroller), but on early machines used computer as controller and they have to deal with this.

I have some experience with modern FDM and SLA, and I seen many cases, when FDM was severe limited with microcontroller PWM range.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#158

Post by vel0city »

kragen wrote: post #142
vel0city wrote: post #119

Earlier quoted context omitted.

I mean "render the gcode" as in going from a 3D model to the gcode you want your tool to follow. Following the gcode would be generally pretty simple; I agree. However, I doubt most home hobbyists had computers in their house in 00000000001959 capable of manipulating 3D graphics in a meaningful way that would really be approachable to a general hobbyist. Wikipedia suggests 1960s CNC's were often controlled by a PDP-8…

We were talking about "the 70s and 80s", not 01959. My point about APT is that a "beefy machine" in 01959 was the embedded controller in your keyboard by 01983; it wasn't a beefy machine any more. The PDP-8 was indeed pretty common for CNC control in the late 01960s, and it could run about 333000 12-bit instructions per second, which is about half as fast as the original IBM PC. So, yeah, a machine like that was exac…

> it's possible I have a different concept of general hobbyists than you do

Yes, we're talking about very different levels of hobbyists here. I'm talking about the people who are frequently doing 3D printing today. They're often not thinking about the actual algebra and Bézier curves and what not. They're playing around in CAD software extruding surfaces and connecting vertices and what not, if they're even going that deep. They're downloading pre-made models off Thingverse and printing them with their printer, tinkering with the physical aspects of their printers. Lets try printing this model in this material, lets mess around with this fill, what if we print it at this angle, etc. They're not digging deep into the code of how the CAD application actually works to draw the curves. They absolutely wouldn't be hand typing out the functions to draw The Rock's face on to a toilet, letting it render all night long, going back to tweak their math, letting it render all night long, rinse and repeat.

> on an IBM PC-XT with a 4.7MHz 8088

> the machines had two video cards

A pretty high-end machine for many home users (~$5k new in 000001983, almost $16k today). I realize there were even higher end machines out there though.

> a version whose 3D functionality was inadequate for any real use

Exactly my point. And when would that machine have come out? The PC-XT released in 000001983. So even in 000001983 decently high-end home computers with $001,000+ (of 1982 money, >$3k today) software suites weren't very suitable for even basic CAD work without many pitfalls and limitations.

So general home users who barely passed highschool algebra and don't have degrees in mathematics trying to use 3D printers wouldn't really have the compute capacity to think about what they're trying to make and modify without getting really deep into it, at least until about the 90s. The 3D printing scene as it exists today pretty much couldn't exist until the 90s. Sure, very smart people with piles of cash could have done it in 000001980, potentially even the mid 000001970s, but not like a go to the computer store, buy all you need for <$000,500 (about $000,060 in 000001970s money), plug in to your cheap $000,200 (about $000,020 000001970s) computer, dial into the BBS, grab some files for The Rock's face on a toilet from your BBS, and start printing in an afternoon.

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#159

Post by stevekemp »

kragen wrote: post #154
stevekemp wrote: post #149

Earlier quoted context omitted.

Sure floating point is possible, but if you're thinking of something like a 6502 or Z80 you'd have to implement it yourself - no maths co-processor, or dedicated instructions for it. In terms of paging I was thinking of paging in later layers of data from disk, perhaps from a large file, perhaps from a series of files. But CP/M certainly did have support for paging RAM, in 3.x, if your hardware supported it. (My own…

Yeah, people did do overlays a lot on CP/M. If you were using a 6502 or Z80 in the late 70s you wouldn't have to write the floating-point routines; you could just call the ones in the BASIC interpreter you probably had in ROM. They'd still be slow. As for paging RAM, do you mean bank switching? The 8085 and Z80 didn't have MMUs, so you couldn't do "paging" in the sense people normally understand it today.

Bank switching was the term I should have used, thank-you!

Re: Ask HN: Why did consumer 3D printing take so long to be invented?

#160

Post by Suppafly »

kragen wrote: post #147
Suppafly wrote: post #127

Earlier quoted context omitted.

Sure but they did by the 80s and 90s. I had a cad/cam class in the 90s and the pen plotter we used, not sure which model but HP 7090 from the 80s is similar, had all the technology necessary to build a 3d printer. Hell you could build a 3d printer from essentially first principles using old broken tech and stuff from a hardware store. The first time I saw a 3d printer years ago, my first thoughts was why it took so l…

You will probably be interested in reading my summary in https://news.ycombinator.com/item?id=42080682 of the things the RepRap project struggled with in the first years of the project; it explains why it took so long.

>They wasted a lot of time trying to make it work without even a heated bed, to keep costs down.

I'm not trying to downplay the reprap team and their work did lead to some of the innovations in home 3d printing, but I suspect a lot of the project is like this, losing time by ignoring things that already existed and trying to reinvent things using cheap household items by going down unnecessary rabbit holes. Thank god that people serious about actually making a shippable product actually got involved at some point or it'd all still be theoretical.

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