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> 1. Just look around you: Where do...

I mean, I actually see quite a few, but none of them are things that I would ever bother printing since I can just pop around to the store and buy a new garbage can etc...

> 3. FDM printing is inherently an unreliable process

Yeah, I have a well-tuned and reliable machine and it's not really cut out for long stretches of lights-out operation. Worse, most failures are at the bed/plastic interfaces. If you're printing conventionally, that's great because things fail early - but this belt process manages to stretch out the process of making that interface throughout the entire print.

> FDM based printing is a dead end in the history of 3D printing

I don't think so. It's a mature technology, and is already quite useful. It's not going to radically improve in terms of geometric accuracy/feature size, but materials are constantly improving and I'm excited for stuff like ASMBL, tool changing printers, and more multi-material/multi-process integration in general. I don't really see 3DP ever getting to "magical replicator" levels, so if FDM is a dead end, it has found a nice little cul-de-sac in the same neighborhood as the eventual end-game printing process.

most resins are nasty, toxic materials that you dont want to have around in your home

Got a source for that?

I've been using Formlabs resins since they did their SLA Kickstarter ~6 years ago. Never seen any toxicity warnings in their MSDS. Know lots of other people who use them, including a couple who ignore all the guidelines and get their hands covered in the stuff. The worst I've heard of is something like a skin allergy reaction after prolonged, chronic contact. The company themselves have dozens of employees printing with these things in regular office environments and their homes, and I imagine would get a nasty lawsuit if it turns they've been subjecting their staff to toxic conditions. Also know loads of people who run with third party resins (e.g. Peopoly is popular at the moment).

Eye irritant and skin irritant. The only toxicity one mentioned is reproductive toxicity; it causes reduced fertility and shrinking of the testes:

https://archive-media.formlabs.com/upload/Clear__Resin_SDS_E...

> Repr. 2, H361f (Fertility, causing [1] atrophy of the testes)

That's for uncured resin, which you shouldn't touch anyway. I think protocol calls for using gloves when handling this stuff.

Do you happen to know if that fertility issue is only for clear resin, or all resins they offer?

Frankly somewhat surprised to learn this. I think I've seen them push clear resin for microfluidic applications where you would have biological samples, which would indicate low or no toxicity.

> That's for uncured resin, which you shouldn't touch anyway. I think protocol calls for using gloves when handling this stuff.

This is the issue with hobbyist use. Of course there are protocols to handle it safely, but such things make it inappropriate for the average joe.

I agree with you it's not for the "average joe".

I.e. yes you need to be really careful not to touch the uncured resin, cleaning up is a bitch, and you need really good ventilation when you're developing with isopropyl alcohol.

But for folks who do manage to somehow get a room dedicated to this craft, of a hobbyist hackerspace with a dedicated spaced, it's probably fine. And, I think arriving to the point of being able to make a good print (modeling, slicing, etc.) is a good enough filter -- folks who can do that will and should understand you need to wear gloves when operating this thing. And I do believe if you get a printer it comes with a few gloves so that is made pretty clear.

The resin itself isn't a huge problem. It's that it will enter and cure inside your body. This causes an allergic reaction that will grow stronger over time until it becomes unbearable.

> Just look around you: Where do you see bigger than 300mm^3 (around the maximum size of common FDM printers) plastic objects? Barely any.

I wonder if that's a effect or a cause though?

There were barely any cars on the road in 1900. There were very few super computers in people's pockets in 2000.

I know literally 3 or 4 people who'd jump at the chance to use one of these to print model glider wings (or at least moulds for them). There might be several hundred or even _thousand_ potential customers for that around the world ;-)

I can't think for any actual real world useful use cases for this, but I'm somewhat hesitant to use the "but nobody has the kind of thing this makes possible now" argument against them... I am highly aware of my lack of imagination and my innate ability to go "Well, yeah, that's obvious!" after someone with a way better imagination than me does something creative with new tech...

>1. Just look around you: Where do you see bigger than 300mm^3 (around the maximum size of common FDM printers) plastic objects? Barely any. Larger single-piece objects (or parts of them) are made from metal, wood etc.

The guy (NAK3DDesigns) who created the design the Creality Ender 30 is based on is exclusively printing large objects like guns and swords as two halves that he glues together. Pretty much most of them are longer than 1m. If I had such a printer I probably wouldn't hesitate printing 50cm long parts.

>2. To make things worse FDM parts are weaker than injection molded ones, your big parts will be very brittle.

Not everyone can afford to spend a few thousand dollars to make single unit parts. Especially when you exceed the size of most injection molding machines you would have to either use multiple molds or one gigantic one which will cost more than $10000 for something you only make once.

>3. FDM printing is inherently an unreliable process. There are lots of moving parts (the simplest FDM printer needs 4 motors, lots of belts, idlers, gears etc) and very tight tolerances (e.g. the print needs to begin 0.08-0.12mm above the printing plate; the whole priting plate needs to be very level and parallell to the printhead.). This is achievable at surprisingly low cost today (an entry level Creality printer is <200$)

The reason why 3d printing is low cost is that rigidity requirements are low. On a 3d printer you don't even need a ball screw or linear rails. Just a belt with a crappy tightening mechanism and some plastic rollers on an aluminum profile are enough. There are no cutting forces in a 3d printer and the print head weighs laughably little so you can get away with small stepper motors.

>I am starting to think that FDM based printing is a dead end in the history of 3D printing (mainly because of reason #3). Likely the future is resin - a simple LCD resin printer has 1 moving part. But they need to solve the issue that most resins are nasty, toxic materials that you dont want to have around in your home.

Funny that you say this but I personally don't want an SLA printer precisely because of the nasty side effect of photosensitive resin. One day you'll become allergic and that's the end of your hobby. FDM printing is safe and mechanical reliability is just a property of the specific printer, not a property of the process itself.

>"endless" printing is a niche feature that would barely see any use.

3D Printing pieces for large scale unique art projects (some people make a business out of this), producing a steady stream of parts for a small business, printing very long pieces. That's just ideas I had in the last 15 seconds since I read your comment.

I like resin but doesn’t that limit your choices of materials? And isn’t there a lot of post processing?

An increasing library of materials is becoming available for SLA, e.g. I've used those with properties resembling clear acrylic, silicon, rubber, ABS-ish, bio-compatibility for dental, "nano-dispersions" for tinting and even some exotics infused with glass powder or with high temperature-resistance (HDT of 238°C @ 0.45 MPa). But FDM still offers more variety (e.g. carbon fiber infused filaments).

There's post-processing if you do prints that require supports (overhangs, etc). I've gotten good at designing within the constraints of the process to eliminate that as much as possible, but yes, it's still a pain.

A typical advantage of SLA over FDM or SLS is a smoother surface finish. But I think the industry will ultimately land on a material jetting design (akin to an inkjet) that can dispense multiple types of polymers and dissolvable supporting material. The NexD1 had promised to be the first consumer-grade printer to do this but it was a scam.

I print a lot of miniatures which require tons of supports, but the support process most people in my space use result in supports that are incredibly easy to remove - it got to a point for me where I enjoyed removing supports that I was printing too much. Sort of like when we'd put Elmer's glue on our hands just to pull it off after it dried back in school. :)

Post (or pre) support removal is an isopropyl or acetone (or other agent) bath to remove any liquid surface resin and then a final UV curing.

I use an Anycubic curing station so that definitely speeds things up. To process a full build plate from my EPAX X10 it takes upwards of five minutes of my time [in terms of attention] (plus six minutes in the alcohol bath and six minutes in the UV cure chamber, which are both unattended processes).

Interesting. How much faster is the print time vs fdm?

It's much slower than FDM (at least in my experience using a formlabs printer).

It really depends. an LCD resin printer prints a single layer at once, but it prints much smaller layers than an FDM printer (resulting in better quality). So for something small like a minifigure FDM will be faster, but for something big (especially if it has lots of small features) resin is faster usually. And resin prints are always more detailed.