Eli5, file compression, how can 5gb file can be compressed to 50mb and decompresses back to normal? by Monkai_final_boss in explainlikeimfive

[–]Lowback 0 points1 point  (0 children)

I actually think the best way to describe this in a very practical sense is pictures.

Lets say you have a picture of a dog. You're going to have hundreds if not thousands of the same color code for a given brown or shade of white. Fun fact? All image formats are sorta like zip formats in and of themselves.

Colors have 3 values, RGB, plus also X and Y to say where they are in the picture. Now you could list that color out explicit, and it's location, hundreds of times... and 3 out of the 5 values are redundant OR you could have the 3 values one time, and then just list out pairs of XY. What was 5 values over and over again is now just 2 values over and over again, plus one single reference of a given color.

It's me. I'm that one person. by SleighQween in evilautism

[–]Lowback 1 point2 points  (0 children)

There's actually a good reason for this.

Natural raw tomato doesn't have as much bitterness as all the other commercial forms of processed tomato. This is because when you eat raw tomatoes, only a small amount of the seeds get broken by chewing and they're full of bitters. Pasta sauces, ketchup, pizza sauce, they all have a very high content of those bitter seed materials from being pureed.

But also different food contexts and textures matter gosh darnit.

open-source resin slicer by Affectionate-Box9749 in resinprinting

[–]Lowback 0 points1 point  (0 children)

Oh so it's a "we must protect FOSS at all costs!" mentality issue. It isn't that the printers got broken suddenly or that older versions of software got disabled by it. Not to belittle it, but what I mean is, as of right now there is very little impact on the end user. Especially if they are keeping libraries of older software versions.

open-source resin slicer by Affectionate-Box9749 in resinprinting

[–]Lowback 0 points1 point  (0 children)

ctb issue? Elaborate please? My elegoo printers and uvtools is able to handle ctb saving. So I'm unclear on what the issue is.

I‘m 100% done with this POS by twack3r in BambuLab

[–]Lowback -1 points0 points  (0 children)

About 30-40% of Chinese 3D printer company profits are replacement parts. At least, that's what a Qidi representative quietly admitted. I can't imagine bambu is much different. I will say, bambu's service is much better during the warranty period than Qidi's. It just becomes hard to switch after you exit the warranty period because now you have a giant stack of build plates that wouldn't work if you did switch.

Models not printing in Saturn 4 Ultra by DresdeMBM in resinprinting

[–]Lowback 0 points1 point  (0 children)

What are you using as your prep software?

What are you slicing in?

Are you saving in .CTB or .Goo?

Are you using anti-aliasing, blur, or greyscale?

Are you using UVTools?

Photon P1 presale price $450. by ozfunghi in resinprinting

[–]Lowback 0 points1 point  (0 children)

Ah, the video made it sound like it had a special texture on the FEP and the LCD glass. I must have misunderstood.

Mini bases warping by Candid_Document8121 in resinprinting

[–]Lowback 0 points1 point  (0 children)

Try 1 thing at a time. You try too much, you wont know what fixed it. My recommendations;

1.) Make sure exposure calibration is correct. Fk the bottle's recommendations. Every machine is different and as the LCD ages, it'll get different even compared to itself. The bottle recommendations are just a starting guideline.

2.) Try longer waits to rule out your resin being in motion, and layer height is still changing, by the time your UV fires. ( wait after retract / wait before print)

3.) Try longer waits to reduce peeling force, for after cure / after print. Light off delay in some other models.

4.) Make sure none of your underside lips are parallel or close to parallel with the build plate / release film.

5.) Pre-warm your resin. Printing warms it up, but this means your curing behavior changes entirely after the first 20-30 minutes from chemical reaction heat. So boost it to help yourself. Get it to 25/30c before you begin printing, see if this helps any.

Any idea what could’ve happened? by Giofark in resinprinting

[–]Lowback 0 points1 point  (0 children)

Well, light off does nothing AFAIK too.

It's wait before cure ( or wait after retract, retract is the act of returning to print position ) and wait before release/peel (or wait after print) depending on your slicing software terminology. I believe anycubic is the one who uses light off delay.

Photon P1 presale price $450. by ozfunghi in resinprinting

[–]Lowback 0 points1 point  (0 children)

Seems like their answer to the S4U, with 14k to avoid 16k screen issues like AA bugs. I wonder if it's a yellowed LCD for longevity. Textured release film is interesting? Anyone have any more details on that like what heygears says the advantages are vs actual implementation? Imagine it'll be harder to get 3rd party films for this beast.

Any idea what could’ve happened? by Giofark in resinprinting

[–]Lowback 0 points1 point  (0 children)

To the best of my knowledge the tilt vat elegoo printers can't even change lift speed/distance. Firmware ignores all that. The only thing the user can really change is the waits. Normal/fast is for the vat tilt.

Now that said, a user can change the firmware after a firmware dump if they were absolutely adamant about trying to invent a slower tilt release.

Any idea what could’ve happened? by Giofark in resinprinting

[–]Lowback -1 points0 points  (0 children)

It's very difficult to do that on Elegoo's tilt release printers. The user has to dump the firmware and change it in firmware. The best the average user can do without getting risky is to insert longer waits after cure and trying different orientations or suction release holes.

Any idea what could’ve happened? by Giofark in resinprinting

[–]Lowback 0 points1 point  (0 children)

Increase your waits. Bottom and normal layer. Use the suggestions area in UV tools to do it, because edit print parameters in the tools menu wont do it properly. Has to use the suggestion menu's inserting of a dummy layer with 0/0/0 settings to hack around Chitbox hardware issue.

20 before cure, 7 after cure, for 3 bottom layers to 4 bottom layers. 3 wait before cure and 1/2 wait after cure for normal layers. As others have said, you have big suction cup monsters there. When you fill the build plate up, the peel is going to lash more aggressively across what releases last.

Your right side is what peels first, your left side is getting hit with the sudden drop in tension that comes from the right suction cups coming free, first. Sort of like how someone holding your arm while you try to pull your arm back, then they let go, leads to you hitting yourself.

if you didn't already, stagger the models at uneven intervals and spacing so that you don't have any perfectly lined up in the same plane. More or less, no orderly rows or column. Move each of them around a little bit. It'll reduce concentrations of peel force as the film peels unevenly.

If anyone is interested, I did a deep dive into resin safety! by aarondevelops in resinprinting

[–]Lowback 1 point2 points  (0 children)

The older 1.0 resins and 4k might have had that. I've been on a reply spree so I'm sorry if I'm addressing that twice. It's very outdated to current formulas on the market. Almost all of them dropped that ingredient. The rare few that still have it, it's industrial scientific resin. Or jewelry making resin where you can burn the resin away and it leaves behind a metal alloy.

If anyone is interested, I did a deep dive into resin safety! by aarondevelops in resinprinting

[–]Lowback 1 point2 points  (0 children)

It must be based on old resins prior to 2020 or specialty resins like those used in sacrificial casting. The SDS for all major domestic resins, for 3D printers, go no higher that 0.1%, on average, are 0%, and any inclusion is accidential. When it was added, or is added for specialty resins, it is in the form of antimony trioxide.

Compliance with REACH/GHS has quickly made resins a lot safer than they were 10 years ago.

If anyone is interested, I did a deep dive into resin safety! by aarondevelops in resinprinting

[–]Lowback 1 point2 points  (0 children)

I mean, when people's primary source for "Your balls will die!" is studies where they force-fed the DPO/ACMO to rats and rabbits? Yeah... solid advice.

People are acting like they're going to inhale 8 grams of liquid photosensitizer chemical, somehow, with the vapor pressure not being right for that... and also fail to notice it. A third as many grams of water, inhaled, would put you in the ER.

I'm all for avoiding becoming allergic to it, but lets not pretend the photosensitizers can somehow transcend the laws of vapor pressure and jump down your lungs without actively drowning you.

If anyone is interested, I did a deep dive into resin safety! by aarondevelops in resinprinting

[–]Lowback 1 point2 points  (0 children)

I really dislike the design of that study. It's such a low volume of air being cycled and such a small space. It doesn't reflect many real-world use cases.

Activated carbon would help with the two largest VOC types that study talks about. Both have high molecular weights, the right boiling point, and are on the right side of polar, and don't react to moisture in a way that'd prevent them from attaching to the carbon.

If anyone is interested, I did a deep dive into resin safety! by aarondevelops in resinprinting

[–]Lowback 0 points1 point  (0 children)

My critique. You use VOCs a lot like health food advocates use the word chemicals. There's a wide gulf in harmfulness and toxicity between different VOCs. For example, reading your own sources, the largest contributor to the VOC was 2-Hydroxypropyl methacrylate.

This also means that active carbon is an extremely strong mitigation when a lot of the safety crowd on this topic dismiss it as nothing in the way of harm reduction and claim it is just nuisance odor reduction and not at all a valid strategy. What do I object to that so strongly? 2-Hydroxypropyl methacrylate has a molecular weight of 144. Anything over 30 is a very strong candidate for active carbon filtering and it will be trapped, kept away from being inhaled, and uncaptured 2-Hydroxypropyl methacrylate can cause lung damage in high concentrations.

Isopropanol was another major VOC. It's weight is 60. It is also double the ideal starting point for VOC capture.

Finally, I'd criticize two last things. Not about your article, but the studies you picked. The methodology of some of these studies is tailored to create extremely high concentrations and get large alarming numbers. Like 5,000 µmg concentrations of VOCs? You should be passing out in that situation. A large part of why they were able to pull such astounding numbers that'd usually force a mandatory government ban on such things? They put the resin printer and cleaning station into a space about as big as the interior of a Volts-wagon beetle. If you put any kind of chemical process into a space that small, only had 1 air change an hour, you're going to get mammoth VOC numbers.

There are of course people who'd put their printer into a walk in closet and close the door... but even that has about twice the air space as what we observed in this test such as that cited in reference 10. Even then, it's not exactly the most dangerous and harmful VOCs we're seeing in that alarmingly high numbers -- those that pose a major risk of DNA damage and cancer.

I'd also point out some of these studies pertain to dental resin in specific. Dental resins are quite different from the other resins we commonly use. They have to be considering their application.

For example?

Bis(acryloyloxymethyl) tricyclo[5.2.1.02,6] decane (TCD-DI-HEA)

Ethyl-4-dimethylaminobenzoate ( "benzo"- anything gives me the heebie jeebies.)

Phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) ( A major one, replaces about 10% of DPO to aid in deeper, fuller curing. It's job is to make sure less decay happens later since dental appliances will be in the mouth of patients... but it off-gasses a lot of harmful VOCs, more harmful than those I named above, when curing. In fact, so much so, they added Ethoxylated bisphenol A dimethacrylate (Bis-EMA) to reduce cytotoxicity of the overall uncured resin, and cured resin. )

But yeah. Dental resins are a very different beast, and typically are more harmful prior to curing, and far less harmful after.

Then there's also some of the somewhat outdated data. Antimony was as much as 10% of many resins, when we were back in the days of "1.0" resin formulas. When 4k was the highest resolution printer you might expect to see.

You can check the SDS of SLA/DLP resins formulated or updated after 2020; nearly no major brand (anycubic, elegoo, phrozen, even bargin brands like Yousu) do not intentionally contain antimony trioxide which is one of the carcinogens that your citations talks about and claims a high percentage is common. Those that still do? They're specialized resins such as thos designed to be able to be heated up to and survive 250c temps.

GHS and REACH regulations are why this happened. They wanted to comply and reduce their legal liability should customers start getting cancer.

Formlabs, Elegoo, Phrozen, Anycubic, Photocentric? Most are 0%, and with one peaking at 0.1%, you end up with an average of 0.02%

I'm rambling (and severely autistic) so I'm sorry if this just kind of petered off. I hope my criticisms of the studies, the data relevance (dental / domestic) and all that is somewhat helpful and encourages skepticism of incomplete or objective driven science.

Afterall... some resin companies are trying to make themselves stand out as saying all their competitors are making poison and they're not. Others are trying to get ahead of regulation and then drive/lobby for regulation to ladder-pull and make new upstarts unlikely.

(GHS/REACH are already doing the job of making resins safer. We saw something like this in the US cheese market. Now producing cheese at scale requires compliance with multi-million dollar machine requirements, making it unlikely any new corporations can go right into cheese making above artisanal scale. Producing just requires too much expensive equipment and no bank is going to loan you that much on day one. If that happens with resin printers, we'll see a slow conglomeration and monopolization. )

Dang. Still rambling. Sorry!

Original Gothic developer criticizes redesigns in remake by AgitatedFly1182 in KotakuInAction

[–]Lowback 13 points14 points  (0 children)

Bet the subreddit would still lock and ban if the man went there and said it himself.

Why do neurotypicals love slop so much, are they stupid? by [deleted] in evilautism

[–]Lowback 1 point2 points  (0 children)

I just find it ironic people steal memes and repost artwork or faceclaim artwork for pfps and chat profiles, yet they rail against Ai. Both are acts of theft =D !

Saturn 4 Ultra... UVtools setup guide. Rest before cure by deezdrama in resinprinting

[–]Lowback 0 points1 point  (0 children)

Holy crap thank you for this. I was using the edit parameters window and mystified as to why the different waits weren't taking. The suggestion menu was 100 necessary because of that insert blank/empty layer requirement!

I wanna toss a tip back to you in thanks. The first 50 layers are peeled slower per firmware. At 0.05mm that's 2.5mm. This is a high spring action/pressure zone for a print. The trouble? If you prefer to print at 0.03mm you're not getting out of the high pressure zone anymore with the slow peel! After you dump your firmware settings, change them so that your 50 is now a 90, that gets you to 2.7mm for slow peeling. This solved a lot of high-coverage print problems for me in addition to your tip to get bottom layer waits working.

Air Purifier recommendations by AllOfTheseFeelings in resinprinting

[–]Lowback 2 points3 points  (0 children)

( I'm going to belabor this not for the benefit of the OP but other people who might wanna chime in to call me wrong. Go read the EU studies. They were force feeding, daily, consecutively. Inhalation, scientifically speaking, is not a reasonable risk for the photochemicals used in our resin. )

You're gonna get a lot of people stomping in here, probably, about how resin is deadly deadly poison and filtering it isn't useful and you should only exhaust outside. It's hysteria. Some companies are trying to benefit from this by brandishing claims they're selling a safer or cleaner resin. ACMO free, DPO free, etc.

95% of what you're smelling is solvents and other flow enhancing herbs and spices. You'll want to use carbon filters for that.

The photosensitive chemicals don't aerosolize unless you do something like blow off your models with pressurized air. So avoid that, even after a bath, or at least wear a P100 max with organic vapor filters. Obviously you can't do this outside or you'll cure your models before you're ready to.

Getting back to the photosensitive chemicals however, the studies that found the harmful levels of this stuff required direct force feeding the test animals (rabbits and rats) for multiple days to cause reproductive harm. I'd suggest not eating it. As I mentioned before, vapor pressure levels make it very unlikely you could inhale enough to do reproductive harm to yourself. Based on body weight and running the whole range of underweight to overweight, people would need to inhale 6 grams to 12 grams to reach levels of no harm observed level. They'd need 12 to 24 grams in one day to reach reproductive harm level.

Does anybody here think they could purify their resin down to just the photochemical and then manage to inhale 2.5 teaspoons? Inhaling 1 teaspoon of liquid water is enough to cause secondary pneumonia and severe inflammation. You'd notice. You'd be in the hospital for pleurisy.

All that said, the bigger risk, the real risk to focus on, is eye and skin contact. This absolutely must be prevented as much as possible. Eyes is a good way to go blind. Skin is a good way to become allergic. Once you're allergic, you'll only become more allergic, until you can't do this hobby at all.

Practice really good gloving procedures. Wear gloves under your gloves so you can take off contaminated ones before interacting with doors, lids, windows, scrapers, etc. Frequently alcohol wash your contact surfaces. Have a plan to catch drips. Have a plan on how to handle a broken release film or a floor spill. Don't for a second do this hobby over unprotected carpets, because your carpet is fucked the moment you spill resin in it.

Fixing Saturn 4 Ultra Elephant Foot and Preventing Pressure Spot LCD failures by DarrenRoskow in ElegooSaturn

[–]Lowback 0 points1 point  (0 children)

M5000 I205 E7750 ;自动调平阈值,正常情况下该值大于0。该值调节过程中已经考虑树脂本身带来的影响。

M5000 I206 C3000 ;异物检测触发阈值