Resin printing problems, what am I doing wrong?

[ikcdab]

This is a follow up from my original post which I started the thread with.

So I had a typical experience yesterday.

1. i printed a few 4mm scale signal lamps and signal platforms - so small stuff. All printed perfectly. Great, we are on a roll.

2. then without cleaning or doing anything else i tried to print 3 girders, each about 100mm long by 10mm high. These have printed perfectly before so i know the supports and the file are all OK. Total failure, no print at all.

3. So i cleaned out the vat, filtered the resin to remove bits, polished the glass screen and cleaned and relevelled the build plate. I then tried to print 3 x SR concrete tool sheds. One came out OK, one half printed and one was the usual pile of mess in the bottom of the vat. 

All other variables are the same. The printer is in a spare bedroom which is heated. This is using elegoo water washable resin. This is the Saturn printer.

Here are my settings - are these OK...? Please comment!

 

So today I am going to renew the FEP film and have yet another go. I do find this all very frustrating. I see on youtube people printing the most wonderful things, yet I struggle to to get any kind of consistency on the simplest items.

 

Grateful for all of your comments!

 

Ian

 

[GWR57xx]

Have you tried any other resins?

There seem to be several reports online of issues using the water washable type.

[ikcdab]

1 hour ago, GWR57xx said:

Have you tried any other resins?

There seem to be several reports online of issues using the water washable type.

No i havent, I have only used the water washable one. My issue is inconsistency - sometimes it works and other times it doesn't. As I have always used the same resin, I'm not sure that is the problem?

Ian

[PhilH]

Have you done the exposure pattern test to make sure all is well with your UV light source? What percentage power are you running at?

 

[ikcdab]

38 minutes ago, PhilH said:

Have you done the exposure pattern test to make sure all is well with your UV light source? What percentage power are you running at?

 

Yes I have done the light test and ask seems ok.   I don't know about the percentage power, how do I set that?

Looking at the glass screen very closely, I can see tiny scratches (about 30mm long but very shallow) in one spot on the screen. Ive no idea how they got there.  Can minute scratches diffuse the light source? The printer is meant for home use so must be able to deal with things like that. 

[PhilH]

On checking my Elegoo Mars 2 pro I’m now not sure if you can adjust uv power, sorry. Certainly you can on my Anycubic machine but can’t find it on the Elegoo. As regards the scratches I’m not sure they would have any adverse effect if they are indeed minute. By glass screen I suppose you mean the lcd screen, one thing is an absolute must is a screen protector in case of spillage or Fep failure. I don’t know if your machine comes with one ex factory, if not get one on asap. 

One of the reasons I think that minute scratches don’t matter too much is that when I applied a protector to my Mono x I couldn’t get all the air bubbles out so there are bubbles in it. I did worry that it would make a difference to printing quality etc., but it would appear not.

[stevel]

I don't think your doing much wrong, if anything. I have heard a few reports of very inconsistent results with washable resins.

I found these settings with a G search, they might help some.

 

[PhilH]

When I got my Anycubic Photon Mono X I was very disappointed after the first few attempts at printing with it. Results were variable to say the least, ranging from superbly detailed prints to shapeless blobs stuck to the fep. There seemed to be  no rhyme or reason to it.

 

The game changer for me on this machine, and the only change I’ve made, has been to ensure that the resin is ~25deg. C. before and during a print. I now do this using the fermentation belt detailed in a previous post, prior to this I spent a fortune heating the house to this level. I’ve now done enough printing without a failure to convince myself that this is not a coincidence.

 

Whether the bigger printers are more susceptible to cooler temps I don’t know, maybe the above is a load of nonsense, but it seems to work for me.

 

Caveat…I use various makes of ABS like resin, all seem to work ok, I don’t use water washable as I’ve heard a few negatives about it.

Edited February 1, 2023 by PhilH

[stevel]

50 minutes ago, PhilH said:

When I got my Anycubic Photon Mono X I was very disappointed after the first few attempts at printing with it. Results were variable to say the least, ranging from superbly detailed prints to shapeless blobs stuck to the fep. There seemed to be  no rhyme or reason to it.

 

The game changer for me on this machine, and the only change I’ve made, has been to ensure that the resin is ~25deg. C. before and during a print. I now do this using the fermentation belt detailed in a previous post, prior to this I spent a fortune heating the house to this level. I’ve now done enough printing without a failure to convince myself that this is not a coincidence.

 

Whether the bigger printers are more susceptible to cooler temps I don’t know, maybe the above is a load of nonsense, but it seems to work for me.

 

Caveat…I use various makes of ABS like resin, all seem to work ok, I don’t use water washable as I’ve heard a few negatives about it.

Heat cured my printing issues also, and a cardboard box over top to keep the heat.

[ikcdab]

Thank you to all who has replied.  This is what I am finding frustrating.  Here we have three models.  A PW hut, tool shed and coalbunker.  I have duplicated the models in chitubox after adding supports so the duplicates are identical. You will see that in each case, one has printed ok, the other has failed.  The toolshed appears to have slipped a portion of the side.  This looks to me as if it's supports, but why would one work and the other fail?

 

Any advice?

 

 

 

PS I had already removed one coalbunker hence only one in the pic.

Edited February 2, 2023 by ikcdab

[PhilH]

Have you tried a higher density of support? I don’t use Chitubox much now, nothing wrong with it but prefer Lychee. On there my go to are medium supports at normal density (I can’t be bothered to add them manually, so let the slicer do it for me).

Yes, there is usually a forest of them which some would say is a waste of expensive resin….but if it saves one print and all the associated clean up etc. for me it’s well worth it. They strip from the print easily enough.

This what atypical print would look like with supports as above.

Edited February 2, 2023 by PhilH

[ikcdab]

15 minutes ago, PhilH said:

Have you tried a higher density of support? I don’t use Chitubox much now, nothing wrong with it but prefer Lychee. On there my go to are medium supports at normal density (I can’t be bothered to add them manually, so let the slicer do it for me).

Yes, there is usually a forest of them which some would say is a waste of expensive resin….but if it saves one print and all the associated clean up etc. for me it’s well worth it. They strip from the print easily enough.

This what atypical print would look like with supports as above.

Hi Phil, yes thats a good point.  Each time I have a failure I say "never again" and then a couple of hours later I am having another go.  I have lychee so I'll try that today and see what happens. 

Looking at my fusion 360, I have made the walls of the huts quite thick, 1.5mm, plus the prototype reinforcement, and the roof is 2mm thick so it is quite a heavy model.  I might try thinning them a bit to make it lighter.

Ian

[PhilH]

1 minute ago, ikcdab said:

Hi Phil, yes thats a good point.  Each time I have a failure I say "never again" and then a couple of hours later I am having another go.  I have lychee so I'll try that today and see what happens. 

Looking at my fusion 360, I have made the walls of the huts quite thick, 1.5mm, plus the prototype reinforcement, and the roof is 2mm thick so it is quite a heavy model.  I might try thinning them a bit to make it lighter.

Ian

 I wouldn’t worry too much, those tank hulls in my example are solid, so pretty weighty. 

[Graham R]

Hi Ian

 

To eliminate (or at least control for) another uncertainty, spend three quid on a digital thermometer (search on eBay or elsewhere for something like “LCD Digital Fridge Freezer Thermometer Temperature Gauge”), put the probe in external contact with the resin tank, lead the display outside the printer cover, and check what temperature you are actually printing with each time. I have been printing successfully with an Anycubic Mono SE in a cellar as low as 8 centigrade: I use a crude insulating-board enclosure and a vivarium heater pad to get the starting temperature up to 16 or so and once printing starts it runs at 23-25 since the process releases heat. If refilling from the resin bottle, put it on a radiator first to warm up. I’ve had very few failures. I can understand your frustration since, at first, nothing printed at all. Anycubic diagnosed faulty firmware and guided me through a field upgrade which solved the issue. I do wonder whether you have some sort of intermittent problem with exposure. I don’t know Elegoo or their field support but have you tried asking them for advice?

 

Anyway keep going, you will solve it, you are not doing anything fundamentally wrong.

 

cheers

Graham

Edited February 2, 2023 by Graham R
typo

[monkeysarefun]

My printer is in a metal shed. In summer it can reach high 30's, low 40's inside, even at night it'll be mid twenties. I rarely ever get a failed print, I call it "The printing season".

 

In winter the shed will be down to single figures overnight, in  daytime will usually be low twenties - the amount of failed overnight prints I get in winter means that I just don't bother to do big prints then. 

[ikcdab]

I am having slightly more success now, though still not reliable.

I ran one print that came out well.  Great, so I started another and that failed completely.

So I relevelled the bed and now ok.

So, does anyone else have to relevel the bed for each run?

Ian

[monkeysarefun]

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.

[PhilH]

7 hours ago, ikcdab said:

I am having slightly more success now, though still not reliable.

I ran one print that came out well.  Great, so I started another and that failed completely.

So I relevelled the bed and now ok.

So, does anyone else have to relevel the bed for each run?

Ian

Definitely shouldn’t have to. As an example I’ve just done 66 prints over two weeks on two printers for the Army project with one failure which was my fault due to orientation and support issue…so I would definitely say you shouldn’t have to do that unless there actually is a fundamental issue with your printer. The only thing I really pay attention to is resin temp which I measure before each run, if not >20deg c. I either use the heater band or blast it with a fan heater.

 

Are all of the screws etc. tight on your printer? It might be worth giving it a once over to see if you can identify any problems. Another thing if not sticking to build plate is that it needs scuffing up.

 

As far as resin goes and in response to earlier post I only use ABS like resin as I find standard too brittle. As detailed fortunately I don’t seem to have problems with it.

 

BTW I assume you’ve dialled in your printer to the correct settings for the resin you’re using?

 

 

Edited February 25, 2023 by PhilH

[Arun Sharma]

I routinely check the level of the build plate before each print run - it only takes a minute or so. Like you I have only ever used Elegoo Water Washable resin - usually Ceramic Grey but occasionally Mint Green. I have found that mixing the two in the tray is fine and has no effect on the build. 

As far as the FEP film goes [assuming no holes or leaks] the main problem is going to be scratches giving rise to an area where resin has hardened in the scratch. This will give rise to a consistently poor uv transmission and hence incomplete or absent curing. Thus if the piece has any significant mass, then it will be more likely deform along the line of partially cured resin.

Personally I have never paused a print although the software allows it. Given that resigration is of the order of microns, it seems very simple to spoil the registration and alignment.

 

I tende to leave the resin in the tak for days/a couple of weeks at a time and it seems to do no harm. If a print fails, then I agree that filtering the resin in the tank and examining the FEP is essential. Again, try not to scratch the FEP or LED.

 

Regarding supports: Most of my prints are 7mm scale. If I was printing something the size of a hollow matchbox or AA battery, then I would use medium supports as well as a raft/skate. 

 

I have attached two pictures - the first is the settings I use and the second is a screen shot of orientation of part of a 7mm Routemaster [front part of the upper deck route display]. Note that this has been turned though 45degrees TWICE not just once. This minimises the pull on the FEP because the strain is taken by the raft which has the effect od spreading the load.

 

Hopefully that will help.

[ikcdab]

Thank you for your replies.

Trial and error means that I can now get a more reliable result. But now to my next issue, warping.

Here are some 009 open wagons. They printed fine with water washable resin. I then wash in lukewarm water and then about 10 to 15 mins in the UV curer.  

This is a home made curing box. The prints are static in this, ie no turntable, but I move them around every few minutes.

 

At that curing stage, the sides then warped out. I found that if I heated them with a hairdryer, they would go back into shape. Great, I thought. So then under coated with rattle can and top coated with acrylic through the air brush.

Then I added a sand load fixed with PVA.

Now look at the result. Massive warping to the extent that one has cracked at the corner.

 

 

This is not the first time this has happened, this is the second print.  Those did the same without the painting and sand load.  The cured resin just seems to keep moving and I don't know why. Is it on the printing process? The curing... Do they need to be constantly moving on a turntable? Subsequent temperature changes.... Or are my wagons just too thin with sides 1mm thick. 

My next move is to print them with reinforcing sprues.  The sides are only 1mm thick, so maybe I should thicken the lower sides below the load for added strength.

Any comments?

Ian

 

Edited April 29, 2023 by ikcdab

[PhilH]

When are you removing supports? Others may have different views but I found I was getting warping and general deformation when I removed supports immediately after washing. I now wait till everything is fully cured (I invested in a wash and cure machine, one of the best £90 I’ve ever spent) before removing supports, As I said earlier I exclusively use Sunlu ABS like resin, but the combination of this resin and above way of doing things has eliminated the previous problem.

[ikcdab]

2 hours ago, PhilH said:

When are you removing supports? Others may have different views but I found I was getting warping and general deformation when I removed supports immediately after washing. I now wait till everything is fully cured (I invested in a wash and cure machine, one of the best £90 I’ve ever spent) before removing supports, As I said earlier I exclusively use Sunlu ABS like resin, but the combination of this resin and above way of doing things has eliminated the previous problem.

I remove supports before curing. It seems impossible to remove from the build plate with supports in tact.  I normally just cut through the supports with scissors to release the model. Then I gently remove the remainder while washing. In any case, I don't have supports across the width anyway.  Maybe I should add some crossways bracing at design stage.

Ian

 

[PhilH]

12 minutes ago, ikcdab said:

I remove supports before curing. It seems impossible to remove from the build plate with supports in tact.  I normally just cut through the supports with scissors to release the model. Then I gently remove the remainder while washing. In any case, I don't have supports across the width anyway.  Maybe I should add some crossways bracing at design stage.

Ian

 

Thinking about it when post print pre curing the resin is very soft and flexible. If you are printing 1mm thick sides and removing supports before the resin has a chance to harden off in my opinion it is almost certain to deform. 
 

As to removal from build plate  on my mono x I invested in a flexible one as I found it virtually impossible to remove standard resin prints from it, the resin being very brittle it was akin to firing shrapnel everywhere. On the mars 2 pro it has a heavily scuffed standard plate from which it is relatively easy to remove prints with the supplied scraper persuaded with a few taps from a piece of 2x2 wood. Again this became easier when I changed over to the less brittle abs like resin.

[Trainshed]

Hi, also check that your build plate is spotlessly clean. Clean with isopropyl alcohol. If you want to go even further, try sanding the build plate on a flat surface with 600 grit wet and dry sand paper. Sanding and a good clean fixed my issues with models not sticking to the build plate (Elegoo Mars 2 Pro).

I also discovered that prints were failing due to the z axis servo becoming sticky. When I took the servo apart, the top bearing must have become contaminated with resin and was really stiff, so that every so often the servo got stuck and would ruin the print.

Once I replaced the bearing, normal operation resumed.

 

Also, I only use ABS like resin now, as the normal stuff is way too brittle. I have found that Jayo resin is ok and cheap at £16 for a kg bottle.

Hope this helps.

[billbedford]

On 29/04/2023 at 08:49, ikcdab said:

Thank you for your replies.

Trial and error means that I can now get a more reliable result. But now to my next issue, warping.

Here are some 009 open wagons. They printed fine with water washable resin. I then wash in lukewarm water and then about 10 to 15 mins in the UV curer.  

This is a home made curing box. The prints are static in this, ie no turntable, but I move them around every few minutes.

 

At that curing stage, the sides then warped out. I found that if I heated them with a hairdryer, they would go back into shape. Great, I thought. So then under coated with rattle can and top coated with acrylic through the air brush.

This is not the first time this has happened, this is the second print.  Those did the same without the painting and sand load.  The cured resin just seems to keep moving and I don't know why. Is it on the printing process? The curing... Do they need to be constantly moving on a turntable? Subsequent temperature changes.... Or are my wagons just too thin with sides 1mm thick. 

 

Any comments?

 

 

Resins absorb whatever liquid you clean them with. Prints should be left to dry at least overnight and preferably for more than 24 hours. Curing on the supports can also help to minimise warping.