Designing for current gen resin printing

[Iain]

Is there a single place where I could find advice on printing with current gen 3D printers?  Things like print angle, supports, feature size, etc.  I know some of these things are scattered in posts in this here forum, but it'd be nice to have things in one (ideally stickied) thread.

[Lemosteam]

Resin printing has SO. MANY. VARIABLES. It’s just not that simple. Almost every user I have seen here and on various Facebook groups has to learn this lesson.

It’s not formulaic at all. Each user ends up coming to their own conclusion, which is why recommendations are hard to find.

Here’s a list of variables to contemplate a matrix:

Room temp
Humidity
Resin temp
Resin type
UV level
Layer thickness
Lift speed
Lift time
Cure time
Wall thickness
Print size
File orientation
Support structure
Plate leveling (if not automatic now)
Resin shaken
Screen life slicer tools
How you looked at the printer yesterday, lol.

Even if you print the exact same file using the exact same settings, these variables can affect the next attempt.

It’s more complex than a golf swing.

Not trying to be negative or talk you out of it.

Just being honest with my frustrations.

[Sumner]

I'll try and talk you into it......maybe  .  First some history.

I'd been printing a couple years with an Ender 3 Pro (now have two and love them) and put off going to resin.  Finally ordered an AnyCubic Photon Mono in the spring of '21 for $200 but put off using it after reading about the smell, mess in cleaning and lots of other issues.  So it sat a couple years until 2023 before I finally started using it.  By that point I had bought about 3 different types of resin that I thought I would use.

Then someone posted about all the good virtues (fine detail, strong, not brittle, can be drilled and tapped) of Siraya Tech Build Sonic Grey resin. That and ordering a $100 wash-n-cure station finally got me to trying out the printer but thinking this was going to be a long process before I'd be happy with the prints.  Boy was I wrong.  I took the walk before you run approach though.  I found that Siraya Tech has the printer settings on their site that you can use with the Chitubox slicer program that you use to slice the .stl file so the printer can work with it.  Wasn't that hard to download free Chitubox and set up the printer settings in it for the Photon Mono.

First print was the AmeraLabs Town print ....



https://ameralabs.com/blog/town-calibration-part/

....  to see how the printer settings were working.  To me it printed perfect the first time so I now had printer settings to use.  Used those settings on all of the following prints and never changed them one bit.  Used Chitubox and usually tilted the print 45 degrees and let it put in the supports, all in a couple minutes.  Still mostly use that approach but try and put the side I care least about towards the build plate.  More on this further down.

After a couple months of lots of good prints without changing any of Siraya Tech's recommended settings the printer screwed up and the screen went out.  I thought I could get the parts cheap enough to try fixing it but was so hooked that I ordered an AnyCubic Photon M3 also for about $200 and it has a considerable larger build plate vs the Mono.  Again I didn't try any of the other resins I had initially bought as the 'Build' was working perfect for me.  Again downloaded the printer settings for the M3 from Siraya Tech's site, printed the Ameralabs Town.  Printed perfect and almost everything I've printed in the last year and a half has also printed perfect without doing anything with the settings.

I'm not saying one might never change any of the settings, I haven't, but you can get a printer and be getting good prints with it without a lot of work.

Final thoughts....

I print in my shop which has a lager volume of air (27'x40') and have no smell problems and the shop is attached to the house (kitchen is on the other side of one wall) and the wife walks through it to the greenhouse and has never complained and has about other smells.  The 'Build' is low odor.  I use denatured alcohol in the wash-n-cure and it smells when open but not in the wash-n-cure so only for a minute or so. 

I would not resin print without the wash-n-cure.  Using it there is no messing with cleaning and the curing is simple.  I have two wash containers (bought a second one).  Wash for 3-4 minutes in the first wash.  Switch to the second wash for a final 3-4 minutes.  Been using the same washes for months.  Will eventually move the 2nd wash to the 1st wash.  I cure for 3-4 minutes depending on the size and thickness of the print.  That's it.  Off the build plate and washed-n-cured in about 12 minutes.

I also wouldn't want to do this .....



... without a printer station where things are organized and clean.  More on the one above here...

https://1fatgmc.com/RailRoad/3D-Printer-2/page-66.html

I have the shop set at 68 deg in the winter and the swamp cooler comes on above 73 in the summer.  I get consistent prints all year and have done a few hundred from...



.... very small to...



..... larger.

Love the resin printer and only use the filament printer now for larger projects and a lot of those I design to be broken into parts so I can resin print them

Keep it simple (at least at first), get a printer that there is good support for (fixed the first one for $40 and kept it as a backup),  get a resin you can download the printer settings for, print the Ameralabs town and if OK take off printing.

Use the free Chitubox at least at the beginning.  Let it put in the supports, less than a minute and you are usually good to go.  I've found that if a print fails there is usually not good supports at the ends of the prints, like the corner of a building.  I'll let Chitubox put them in.  Then look at those areas and add more or larger ones if I feel they are needed.  You will get the hang of it.

If a print fails, not often then some of the failed parts of resin might be in the vat and on the next print could damage the film.  I am religious about filtering the vat if that happens and wiping it clean and looking to make sure there is no resin cured to the film (see the link above about my printer station).  There are other methods but I want to see for sure.  I'm still on the original film and that very small print further up was printed recently so print quality is great still.

Go for it,  I and others have lots you can print on thingiverse.com

https://www.thingiverse.com/sumner/designs

...and other sites.  Doesn't take long to pay for a printer.

Sumner

[Sokramiketes]

As an engineer, I see the appeal in making the printing variable list extra long and pondering all possible factors.

But I'm a guy that just takes the Elegoo printer out of the box, Sets up the build plate leveling, and hits print.  Could I optimize everything?  Sure.  But that sounds boring... and the risk is that things stop working for awhile.  That's the frustration I hear from Lemo or even Bryan at times. 

Hands off don't touch!  You'll have a 90% good print and that's fine. 

[Jesse6669]

Resin printing has SO. MANY. VARIABLES. It’s just not that simple. Almost every user I have seen here and on various Facebook groups has to learn this lesson.

It’s not formulaic at all. Each user ends up coming to their own conclusion, which is why recommendations are hard to find.

This is the correct answer-- Every modeler here will have a different opinion. 

My opinion(s):
--Most of the standard settings are available online/in the slicer software.  You'll have the settings tweaked in a try or three, and be printing train stuff by the 2nd day.   

--Learn a basic CAD program (TinkerCad is easy and free).  Try a relay box or a cab signal box or some detail you've been wanting but can't find.   

--My biggest downside is mess/cleanup.  I always manage to get a drip of resin on the floor, so don't print over anywhere with good rug/carpet;  I use 99% ISO alcohol for cleanup in a cheap ultrasonic cleaner--this stuff is the best to clean with IMO, but nasty to breathe so do so in a well-ventilated area.  Buy bulk nitrile gloves and a woodworking apron--you don't want this stuff on your skin (or clothes).   For curing, I usually just let my models cure on a windowsill, but sometimes a small UV flashlight can come in handy for "spot curing".   The smell of the printing isn't a big deal, really.

--If the above doesn't worry you (and you have a few $hundred to spare), just do it.. As for myself, with the Black Friday deals, I just pulled the trigger on a 2nd Phrozen Sonic Mini 8K and some resin for just over $300. 

[Scottl]

I've had a printer sitting on the floor for nearly 20 months, paralyzed into inaction.  I just need to try it, but I'm trying to deal with the chemical exposure issues.

@Sumner has provided the most compelling argument I have read at TRW to just do it.

[Chris333]

What chemical exposure issues? Just the smell?

My printer had been sitting for 6 months. I lifted the cover, stirred the resin, and hit print. Works just fine.

[Scottl]

Smell is one aspect but the overall volatiles from the resin and the cleaning product (ISO or similar) are a major concern.  Additionally, I'm not convinced standard nitrile gloves are sufficient for protection.  Many of the resins I have worked with require different barriers like vinyl or more exotic gloves.  Some require such heavy glove barriers that they are not practical as disposables for home use.

Basically, I want the equivalent of a fume hood in my house to do this and practical appropriate PPE.  It is not as easy to come up with as I would like.

There will be people that think otherwise and that I am overly concerned, but I don't spray solvent paints and use thinners in my house for the same reasons.  Each to their own.

[Chris333]

Ah. Yes I would agree that usually the alcohol used to clean the resin smells worse than the resin itself.

I've had good luck with gloves. I only wear one glove and only while cleaning. I use an air hose to blow the glove part way off my hand. Then I put the glove on a foam plate to wait for the next time.

Once in a while a sharp part of the print will puncture the glove. So I toss it and get another. Wash my hands with fresh alcohol.

Bleach makes my eyes water and nose run. The resin doesn't bother me at all. Alcohol can be strong though if you get a good wiff.

[Scottl]

That is all sensible.  I'm just particularly attuned to the risks of resin from long experience.

[Sumner]

I haven't had a resin mess yet and have done a lot of printing (hopefully didn't just jinx that).



I take the build plate off the printer and hold it on those paper towels on the silicone mats in the image above and put them in the basket.  From there the basket goes in the wash-n-cure and that is it for dealing with the resin.

I use the nitrile gloves and that has worked fine for me.  I take the paper towels off the mats and throw them away.  One thing that surprised me is that the resin I'm using doesn't run like water, maybe none do.  If some comes off the build plate while removing the print it stays pretty much were it dropped too.  Throw the towels away or if there is some on the mat it wipes right up.  Same if there is a little on a glove.  I wipe the build plated down, top, edges and build surface with no problems.



Also wipe the pallet knife down that I use to remove prints.  With the wash-n-cure there really is very little handling of the prints while they still are wet.  That knife I couldn't live without.  It works way better than the razor type blade in the picture or real razor blades.  It is easy to pick up the side of a support and work the knife under and down along under the other supports.  I can get small or large items off the build plate in seconds.



I don't leave the vat on the printer, even though the picture above suggests that.  I worry that if there was a small leak (haven't had one) in the film on the bottom of the vat it could end up on the printer glass.  Putting on the mat between the printer and wash-n-cure station prevents that possibility from happening.  The vat has a cover to prevent light getting to the resin and I cover the....



... print station also after any printing, also to keep dust out as we have dust here.  I have had no problems leaving the resin in the vat.  Stirring it before the next print.

I wouldn't want to take the printer in the house myself but would use it in a much smaller space than my shop.  I'm sure some do use it in a spare room though.

Sumner

[Chris333]

See I have never washed the build plate. I loosen the build plate, put a foam plate under it, put it on the table. Then use the supplied with machine scraper to pop the print off onto the foam plate. I put the build plate back on the machine. I do all of this without a glove because I never touch the resin.

Then I take the foam plate with my prints and go to the slop sink area to wash them. Now I put the glove on and get "dirty".

[JeffB]

Ah. Yes I would agree that usually the alcohol used to clean the resin smells worse than the resin itself.

I've had good luck with gloves. I only wear one glove and only while cleaning. I use an air hose to blow the glove part way off my hand. Then I put the glove on a foam plate to wait for the next time.

Yes...  The current resins don't smell much at all and you most definitely smell the IPA more than the resin.  It's even more pronounced when using Denatured Alcohol, which while I think it's a better cleaner for resin prints, stinks to high heaven.

I've switched to using the 9mil gloves from Harbor Freight, they're super durable (I use them for working on the cars too).  They're black Nitrile (forget what they call them), but they're about $16 for a box of 50.  I reuse the gloves until they tear.  Wash any excess resin off them using the alcohol bath you wash prints in, then a final rinse in your last alcohol rinse tank.  Dry with a paper towel, then remove from hands and let dry further.  I can usually go weeks using the same two gloves.

Experimenting with printer settings can drive you a bit batty...  Standard settings off the resin manufacturer's site can get you most of the way to a good print.  But experimenting does allow you to do some pretty spectacular things. 

I'm currently printing Sn2 (Maine Two Foot prototype) Jackson and Sharpe passenger car trucks using Siraya Tech FAST grey resin.  The truck frames feature a pair of nested coil springs (a coil spring within a coil spring).  Through a bunch of experimentation, I've been able to get the exposure settings so that the coil springs print hollow and look like functional springs (I used a "wire" diameter of 0.25mm/0.010").  Using my original exposure settings, this didn't work.  But after doing about a dozen test prints, I was successful. 

Anyway...  Lots of variables, but general settings for each resin work pretty well. 

To add to what someone was saying about all the things that can effect a print...  I've had an instance of getting great prints that I had dialed in the settings for, and when I switched to a new bottle of the SAME resin, the print quality changed completely.  After some detailed investigation on my part, I narrowed it down to the original resin being pretty old.  When I switched to the new resin, I had to completely readjust the exposure settings to get the print quality back.

So pay attention to the age of your resin... 

Temp and humidity (already mentioned) definitely have an effect on prints...  In colder months, I'll heat up the resin in the vat with a heat gun (stir while heating and don't dwell in one spot for more than a second or two) for the day's first print.  Any prints after that, provided you're running prints one after another, you don't need to bother as the resin will be warmed up thanks to the printing process.

Out of all my resin printing experiences, the worst of 3D resin printing is the mess.  The stuff gets everywhere if you're not careful. 

Jeff

[JeffB]

T--If the above doesn't worry you (and you have a few $hundred to spare), just do it.. As for myself, with the Black Friday deals, I just pulled the trigger on a 2nd Phrozen Sonic Mini 8K and some resin for just over $300.

Where was that from?  The best deal I've seen of late for a Sonic Mini-8K (not the 8KS) is the $446 Mini-8K + 1 spare LCD "Bundle" on Amazon. 

I almost pulled the trigger on getting a second one with that offer, but opted to buy two spare LCD's instead as I really only have workbench space for the one printer at the moment.

FWIW...  You can pick up a Mars 4 Ultra (18 micro pixel size) for sub-$300 of late off Amazon.  Build plate is slightly smaller than the Mini-8K, but it has better resolution and a flush mount, built-in tempered glass screen protector and no heavy rubber gasket that keeps the build plate from getting super close the print surface.  This is helpful if you want to print parts right on the build plate, without supports, where you need the bottom of the part perfectly flat with little or no "elephant's foot" on the bottom of it.  You can't easily do that with the Phrozen machines...

Anyway...

Jeff

[Scottl]

Is resin that has not been opened but old (a few years) a potential problem?