Resin printing problems, what am I doing wrong?

[DGO]

For what it's worth I've found thin walls that are not a consistant thickness seem to warp the most, in my case it was a "timber clad wall with internal framework" not that dissimilar to the sides of those wagons, I think that as the resin cures it actually adds stresses to the print, thicker walls have sufficient strength but with thin walls theres no internal strength so they warp, I think this occurs because the shrinkage that happens during curing is not uniform with the thicker frame areas shrinking the tiniest bit more. A few things seem to help, firstly do not over cure the resin the more you cure the greater the shrinkage, secondly make sure you have some internal bracing, a small amount of curve can be removed by warming up the part removing the curve and allowing it to set, but you need to control how it sets, in my case I could put the flat walls between a couple of heavy books for a week and they were fine, but those wagons will be harder to do that with.

 

A number of people have issues with water washable with solid thick prints, the resin in the middle never fully cures and it eventually results in a big split and leaking resin, now this is only a guess but I believe the shrinkage of the cured resin compresses the incompressible liquid resin inside whichj again causes stresses that result in fractures in the resin days or even weeks after the printing

 

In theory for the best curing you would go with a less opaque resin as that allows the UV light to pass through more easily, however for high detail prints a black or dark (blue or grey) is best as this allows less light bleed to occur giving crisper details.

 

David

[billbedford]

29 minutes ago, DGO said:

A number of people have issues with water washable with solid thick prints, the resin in the middle never fully cures and it eventually results in a big split and leaking resin, now this is only a guess but I believe the shrinkage of the cured resin compresses the incompressible liquid resin inside whichj again causes stresses that result in fractures in the resin days or even weeks after the printing

 

If you have liquid resin inside a solid print, there is something very wrong with your settings. Or you don't understand how resin printers work. 

[DGO]

11 hours ago, billbedford said:

 

If you have liquid resin inside a solid print, there is something very wrong with your settings. Or you don't understand how resin printers work. 

 

None the less it seems to occur with some people, I think it's either because they have a void inside the 3d model where the resin is just not cured OR in some way the resin is not properly cured and somehow pools up. I don't know I've never had such issues because I only do thin walled models, but there are a number of examples out there purporting to show solid models that have cracked open at some point after printing (days or even weeks later) and liquid resin has leaked out, there are sufficient reports of this occuring for me to be inclined to believe it does occur, so if we accept that this occurs we then have to work out what is happening that causes it to occur, the liquid resin leaking out would suggest incorrect curing, so the only thing that makes any sense to me is the hypothysis that the outside properly cured resin has shrunk more than the inside  creating significant internal pressure buildup, or the alternative is that there is a chemical reaction going on between cured and uncured resin that causes a pressure buildup,if you can suggest an alternative explanation that fits the evidence I am all ears. 

 

David

Edited June 7, 2023 by DGO

[billbedford]

I suspect these people are using FDM settings in their slicer with a percentage fill in the expectation they will "save" resin. This is never going to work unless each cell is open. It is possible to print hollow shells, but there have to be sufficient drainage holes for the uncured resin to escape. 

[DGO]

2 hours ago, billbedford said:

I suspect these people are using FDM settings in their slicer with a percentage fill in the expectation they will "save" resin. This is never going to work unless each cell is open. It is possible to print hollow shells, but there have to be sufficient drainage holes for the uncured resin to escape. 

 

Quite possibly especially if they purchased a pre supported model from someone else

[ikcdab]

On 25/02/2023 at 14:29, monkeysarefun said:

The one possibility you didn't list in your first post was the resin. Ive read a couple of Saturn reviews such as the one linked below  which describe a litany of inconsistent results and unsuccessful attempts to fix via relevelling, changing settings etc. 

 

https://geekdad.com/2022/08/adventures-in-3d-printing-the-elegoo-saturn-2/

 

Problems in this case were only resolved when they bought a bottle of standard Elegoo grey. Granted, they were originally using ABS like resin rather than your water soluble one but given the similar issues to  what  you are dealing with  that's what I'd be trying next I reckon.

Thank you to all who have helped here. To be honest, a few months ago I gave up and parked the printer in the cupboard.  Trouble is I can't let it rest.

So i have now bought a bottle of standard elegoo resin and I have given up with the water based.

I will try again with the standard resin and see what happens.

Ian

Edited December 11, 2023 by ikcdab

[ikcdab]

On 11/12/2023 at 20:07, ikcdab said:

Thank you to all who have helped here. To be honest, a few months ago I gave up and parked the printer in the cupboard.  Trouble is I can't let it rest.

So i have now bought a bottle of standard elegoo resin and I have given up with the water based.

I will try again with the standard resin and see what happens.

Ian

The good news is that last night's print run was perfect. Best I've done so far! Coincidence? Or just that i used standard resin rathewr than water-based?

Anyway, i am now going to have another go and see if this has the same result.

Ian

[njee20]

I've nothing good to say about water based resins. They're harder to work with, vastly less stable and no less toxic! Glad it's working for you!

[monkeysarefun]

Resin is a funny old thing. I bought an Anycubic M5S or whatever it called - the 12K jobby - and just could NOT get my favourite resin (Elegoo ABS like) to work at all. I just got the initial layer stuck to the bottom of the vat over and over again, even if I dialled the settings to "ludicrous" like 2 minutes or something exposure time  for the initial layers. Non-ABS  resin was fine,  which eliminated levelling, temperature and so on as issues, and I bought at least 3 bottles of ABS-like in case it was a bad batch or old resin etc, all with the same result. Or non-result.

 

In the end I bought an Elegoo Saturn 3 Ultra due to other issues with the Anycubic and the resin worked perfectly straight from the test print, and I've not had a failed print (oh except one when I forgot to hit the "create supports" button before I hit the print button!)  in 4 months of pretty much daily use.

[ikcdab]

1 hour ago, monkeysarefun said:

Resin is a funny old thing. I bought an Anycubic M5S or whatever it called - the 12K jobby - and just could NOT get my favourite resin (Elegoo ABS like) to work at all. I just got the initial layer stuck to the bottom of the vat over and over again, even if I dialled the settings to "ludicrous" like 2 minutes or something exposure time  for the initial layers. Non-ABS  resin was fine,  which eliminated levelling, temperature and so on as issues, and I bought at least 3 bottles of ABS-like in case it was a bad batch or old resin etc, all with the same result. Or non-result.

 

In the end I bought an Elegoo Saturn 3 Ultra due to other issues with the Anycubic and the resin worked perfectly straight from the test print, and I've not had a failed print (oh except one when I forgot to hit the "create supports" button before I hit the print button!)  in 4 months of pretty much daily use.

Yes it is funny stuff. Just run a second print with the standard resin and, again, it's perfect. Using water based I can guarantee it would have failed as I never had two successful prints on the trot. So great, I now have renewed enthusiasm for the printer. 

[billbedford]

On 11/12/2023 at 20:07, ikcdab said:

Thank you to all who have helped here. To be honest, a few months ago I gave up and parked the printer in the cupboard.  Trouble is I can't let it rest.

So i have now bought a bottle of standard elegoo resin and I have given up with the water based.

I will try again with the standard resin and see what happens.

 

Manufacturers will always tune their machines so the published settings work with their standard resins. Try other resins, and new settings appropriate for that resin will need to be found.

 

I found this guy helpful:

 

https://www.youtube.com/watch?v=llQN-70i36M&t=7s

 

His printing guide also helps. https://bit.ly/3OZTPsi

[ikcdab]

9 hours ago, billbedford said:

 

Manufacturers will always tune their machines so the published settings work with their standard resins. Try other resins, and new settings appropriate for that resin will need to be found.

 

I found this guy helpful:

 

https://www.youtube.com/watch?v=llQN-70i36M&t=7s

 

His printing guide also helps. https://bit.ly/3OZTPsi

Thank you that's very helpful. I was using the manufacturers resin, just the water-based version, and using their published settings. My problem was that one print would be perfect yet the next would fail completely, even with the same settings and print file.

I have my fingers crossed that things might have now resolved.

Ian

[billbedford]

1 hour ago, ikcdab said:

Thank you that's very helpful. I was using the manufacturers resin, just the water-based version, and using their published settings. My problem was that one print would be perfect yet the next would fail completely, even with the same settings and print file.

 

How prints fail is important. As is the temperature of the resin. 

[ikcdab]

5 hours ago, KimDurose said:

Tips for problem-free resin printing:

 

Find a quality brand resin and stick with it. Buy cheap, buy twice.

 

Use FEP2 sheets on the vat. Much hardier than the original FEP specification. I’ve printed almost every day since June without changing FEP.

 

Print environment must be at least 20 degrees Celsius or the resin will be too thick and not have chance to flow during lifts.

 

Stir and pre- heat the resin to the consistency of semi skimmed milk.

 

Support the models. Support them some more. No one ever died from using too many supports.😉

 

Use a quality slicer like Lychee rather than the freebie Chitubox. The annual subscription will pay you back in perfect prints.

 

Two stage washout: First in IPA in a STEEL ultrasonic cleaner. Second in running warm water. 
 

Remove supports while washing in warm water. The bonds will soften and come away really easily.

 

Dry on a piece of kitchen towel in a windowsill and leave there to post expose using the sun’s natural UV rays.

 

Post expose large or thick models for no longer than a minute in a UV exposure unit.

 

 

Thank you some really helpful tips here. Most of these i now do, some are new. Since i swapped to standard elegoo resin, the prints have been 100% successful. 

[billbedford]

5 hours ago, KimDurose said:

Tips for problem-free resin printing:

 

Much of this sounds like the usual internet voodoo. 

 

5 hours ago, KimDurose said:

Find a quality brand resin and stick with it. Buy cheap, buy twice.

For the last few years, I've used some (semi-)professional resin that costs £180 per litre. Consequently, all the resins which people talk about look very cheap. However, almost all resin suppliers offer various formulas with different characteristics. It is worth trying some of these to find one that's optimal for your use. 

 

5 hours ago, KimDurose said:

Stir and pre- heat the resin to the consistency of semi skimmed milk.

The printer can be set up to do all the stirring necessary. I have small heat inside the printer hood that keeps the resin tank at  25-26ºC

 

5 hours ago, KimDurose said:

Support the models. Support them some more. No one ever died from using too many supports.😉

Support quality is a thing. Placement and the size of the support tip are often more important than the total number.

 

5 hours ago, KimDurose said:

Use a quality slicer like Lychee rather than the freebie Chitubox. The annual subscription will pay you back in perfect prints.

VoxelDancer costs twice as much as Lychee. Is it twice as good?

 

5 hours ago, KimDurose said:

Two stage washout: First in IPA in a STEEL ultrasonic cleaner. Second in running warm water. 

Ultrasonic cleaners work by cavitation, effectively producing bubbles from the working liquid. If you insist on using IPA in an ultrasonic, I would ensure you have up-to-date fire insurance. 

 

5 hours ago, KimDurose said:

Remove supports while washing in warm water. The bonds will soften and come away really easily.

I've adjusted my settings so that supports can be easily peeled away. 

 

5 hours ago, KimDurose said:

Dry on a piece of kitchen towel in a windowsill and leave there to post expose using the sun’s natural UV rays.

Uncured resin absorbs both IPA and water. If it is not dried adequately, warping is likely. My prints are left at least 24 hours before attempting to remove the supports. 

 

5 hours ago, KimDurose said:

Post expose large or thick models for no longer than a minute in a UV exposure unit.

Curing with UV links the resin into longer polymer chains, so over-curing is not an issue. 

 

 

Learning to resin print is any other skill. Learners advance by making mistakes and overcoming them. 

 

[njee20]

So you say you need to buy quality resin, and then use about the cheapest resin going…? 🤨

 

I personally think settings and process make a bigger difference than the specific resin, within reason. 

 

I’ll certainly take a lot of your ‘advice’ with a pinch of salt. Washing under warm running water concerns me; you need to catch that water to ensure it’s not going back into the water system. Glad your processes work for you, but I’m not sure you’re a beacon of authority on the subject.  

[tom s]

The IPA left on the parts after the first wash still has resin suspended in it is the concern when washing it down the drain is all, hence the  two IPA wash stages are most popular. Its not like the second IPA wash is wasteful either when the liquid can be demoted to the first stage wash container when the session is over.

[tom s]

1 minute ago, KimDurose said:

I do the first wash in IPA then drop the parts in a container of IPA and give them a swish before rinsing. I count that as one operation. The second IPA (the cleaner stuff) then gets reused in the IPA bath after a few prints.

Ah that makes sense, apologies for the misunderstanding!

[billbedford]

29 minutes ago, KimDurose said:

I find over-curing can also add to the brittleness, hence I try to find a balance.

 

You are using an inherently brittle resin. Not fully curing your models means they will become more brittle over time. Many formulations are designed to be more resilient, but they need a degree of experimentation to discover which is best for your work. 

[monkeysarefun]

1 hour ago, KimDurose said:

 

I’m getting the impression people on RMWeb don’t like others giving advice of what works for them? Touchy subject?

 

 

 

Mate, compared to the  Facebook 3D printer groups,  this is like a gathering of  the Royal Society for Improving Natural Knowledge.

 

 

 

 

In my  5 years of printing, Facebook remains some kind of Dante circle of hell where the damned are forced to endlessly argue the same questions in a loop for ever more.

 

"Sand your buildplate"      /      "No need to sand your buildplate!"

 

 

"I ALWAYS print  flat on the buildplate"         /      "Never print direct on the buildplate!"

 

"You need to use a raft"     /      "Rafts are a waste of resin!"

 

"Follow the manufacturers levelling instructions EXACTLY!"     /     The levelling instructions are rubbish - I just level straight in the vat!" 

 

"I tune my  FEP to 240HZ!"   /         "323HZ is the ideal FEP tune!"

 

"Make sure you calibrate your resin "        /       "Just use the manufacturers values, they designed the resin so know exactly what is best!"

 

etc etc etc etc

 

Those that have lost the ability to write make their points by using  animated GIFS.

 

 

 

 

 

 

 

Edited December 29, 2023 by monkeysarefun

[njee20]

Looks like he’s deleted his account, which seems random. 

 

I was going to say that I think people here are receptive to hearing (and learning from) what works for others, but passing your opinion off as fact is likely to get people’s backs up. 

[ikcdab]

1 hour ago, billbedford said:

 

You are using an inherently brittle resin. Not fully curing your models means they will become more brittle over time. Many formulations are designed to be more resilient, but they need a degree of experimentation to discover which is best for your work. 

Hi Bill, are you saying that elegoo standard resin is inherently brittle? if so, what would you recomend instead?

[billbedford]

Yes, all the first-generation resins were much the same, it's only in the last few years that more resilient resins have come on the market. 

 

I'm using Elegoo ABS 2.0 for most of the models, but I use Sirya Tech Blu for finer stuff like couplings and buffers, particularly the buffer springs. I also have some Photocentric Durable UV80, but I find that a bit softer than the Sirya Tech ones. 

Edited December 29, 2023 by billbedford

[GWR57xx]

I also started with Elegoo standard grey resin. Had plenty of successful prints, but they were very brittle. OK for some purposes, but I wanted something more resilient for printing wagon chassis. I then tried Elegoo ABS like v2 grey and this has been much better (much less brittle, much more forgiving while still being plenty rigid enough for what I wanted).

I did do a lot of exposure test prints though, to find the combination that gave the best results for my needs.

So far these are the only two resins I’ve tried.

I’m sticking with the ABS v2 grey for now, until I find a reason to change.

[monkeysarefun]

35 minutes ago, billbedford said:

Yes, all the first-generation resins were much the same, it's only in the last few years that more resilient resins have come on the market. 

 

I'm using Elegoo ABS 2.0 for most of the models, but I use Sirya Tech Blu for finer stuff like couplings and buffers, particularly the buffer springs. I also have some Photocentric Durable UV80, but I find that a bit softer than the Sirya Tech ones. 

 

 

YEah I remember the translucent green that came with my first gen Anycubic Photon of 2018 or so. I printed off the test cube, carefully cleaned it and cured it as per the instructions, brought it inside out of the sun and promptly  dropped it onto the tiled floor where it shattered into several bits..... That didnt give me huge confidence in the resilience of future prints.

 

Now though, I too use Elegoo ABS V2 and its chalk and cheese, models have the resilience on par with plastic kits as far as flexibility, hardness, and machinability are concerned

 

. The only thing that marks it down for me is that it is quite viscous so models have a fairly thick coating of excess resin on them, even if I leave them in the printer on the build plate  to drain for 24 hours or more, It just doesn't seem to run off.

 

The other thing is a fairly nasty allergic reaction I have acquired, even though I've always been diligent with gloves etc but still inadvertently it does got on me sometimes, for example on my wrists above the gloves if I brush the buildplate on them trying to release prints. There is no visible rash or anything, but it gets unbelievably itchy for ages even if I wash the skin straight away. I do have an identical reaction to spray-on insect repellant (roll-on is fine) and one or two brands of deodorant though, so its possibly me rather than the resin.. (Not that I'd want it on me either way!)

 

 

Edited December 29, 2023 by monkeysarefun