Chewbacca Posted July 17, 2021 Share Posted July 17, 2021 Had my Elegoo Mars since Christmas and after a few teething problems which were largely me not putting in sufficient supports and getting nothing but bases and few supports printing on the build plate, I've now hit a more fundamental problem. Tried to print some davits for my 1/350 HMS PUMA build to replace the PE which is too thin and despite loading them up with excessive supports and trying multiple different angles, absolutely nothing prints. Not even the bases. It gives me all of the indications that it is working properly but then the build plate lifts clear of the resin bath with absolutely nothing on it. And there's nothing printed on the bottom of the resin bath either. I've tried it 3 times with the same results. I haven't changed the print settings from when it was working fine and I've reset the Z plate axis in accordance with Elegoo's instructions. The only thing I can think is whether the resin is contaminated (I use the Elegoo water washable photopolymer resin). I must confess I did leave the resin in the bath for about 3 weeks but before I tried to use it again I emptied and filtered it and thoroughly cleaned the resin bath. Like a muppet though I did pour the filtered resin back into the bottle so I wonder if the resin that was left in the bath had changed its chemical composition due to being exposed for so long (the printer is in a room that faces north so its not as if it is in direct sunlight) and having been mixed with what was in the bottle has now contaminated the entire bottle. Grateful for anyone's thoughts Link to comment Share on other sites More sharing options...
Chewbacca Posted July 17, 2021 Author Share Posted July 17, 2021 Just to expand on that I'm using 65 secs bottom exposure, 8 secs exposure and 0.05 mm layer height Link to comment Share on other sites More sharing options...
bootneck Posted July 17, 2021 Share Posted July 17, 2021 The only time I've had that happen, no print and no residue dropped into the vat, was when the plate hadn't been zeroed and started higher from it's proper setting. You mentioned that you had zeroed the plate so it does't sound like that. My recommendation would be to clean out the vat completely, but don't change any settings. Refill with fresh clean resin and do a test with a QC test print. If that works then you can suspect the STL file, clear all supports and re-support it. cheers, Mike 1 Link to comment Share on other sites More sharing options...
ICMF Posted July 17, 2021 Share Posted July 17, 2021 1 hour ago, Chewbacca said: I must confess I did leave the resin in the bath for about 3 weeks Shouldn't be the problem. Remove vat and build plate from the printer (so it's just the bare, exposed screen) and run the print again. Is anything showing up on the screen? If not, then can you see any light bleed from the LEDs? If the image displays fine, then I guess it's the resin - 'good' resin WILL cure on the FEP if its exposed to UV. If you can't see the image, try running the test screen, or a previously successful print. If the slices appear on your screen as per normal, then the problem is with your file; re-slice and try again (I'd check it with the vat and plate removed, just to make sure). If the slices DON'T appear on the screen, then you've either got a problem with your LCD or the LED array. If you can see light from the LEDs, then obviously they're fine and it's probably the LCD; if you can see a dim outline of the layer on the screen, but no light, then it's probably the LED, not the screen. Open the printer, re-seat the connectors to make sure they're properly connected, then try again. If it's still not working, you probably need to replace the parts diagnosed above. 1 Link to comment Share on other sites More sharing options...
Chewbacca Posted July 18, 2021 Author Share Posted July 18, 2021 Thanks both for your comments. I'll give that a try and let you know how I get on Link to comment Share on other sites More sharing options...
Chewbacca Posted July 18, 2021 Author Share Posted July 18, 2021 Tried the dry print. Absolutely nothing. So I tried the exposure test. Equally absolutely nothing - a completely black screen with no traces of any lit pixels anywhere. So based on your comments that suggests to me that the LED has failed. Is that correct? However, as far as I can see, the only line replaceable part is the LCD screen - Elegoo don't seem to offer a replacement LED or am I misunderstanding your explanation. If I could get hold of a replacement LED (any suggestions where from?), how easy is that to replace? I can find lots of videos showing how to replace the LCD screen and that seems very straightforward but nothing for replacing the LED. Link to comment Share on other sites More sharing options...
ICMF Posted July 18, 2021 Share Posted July 18, 2021 Your best bet would be to contact Elegoo for help. Link to comment Share on other sites More sharing options...
Anthony Kesterton Posted July 25, 2021 Share Posted July 25, 2021 On 7/18/2021 at 8:49 AM, Chewbacca said: Tried the dry print. Absolutely nothing. So I tried the exposure test. Equally absolutely nothing - a completely black screen with no traces of any lit pixels anywhere. So based on your comments that suggests to me that the LED has failed. Is that correct? However, as far as I can see, the only line replaceable part is the LCD screen - Elegoo don't seem to offer a replacement LED or am I misunderstanding your explanation. If I could get hold of a replacement LED (any suggestions where from?), how easy is that to replace? I can find lots of videos showing how to replace the LCD screen and that seems very straightforward but nothing for replacing the LED. Definitely contact Elegoo. The LED generates the UV and the LCD allows/blocks the UV light. Link to comment Share on other sites More sharing options...
Chewbacca Posted July 25, 2021 Author Share Posted July 25, 2021 (edited) Have to say I am impressed with Elegoo customer support. Emailed them last Sunday with a description of the problem. Over the next two days we exchanged emails and photos while they diagnosed the fault before concluding it was definitely the LCD screen, and despite the fact it was technically out of warranty (apparently the screens are only warranted for 6 months) there was no quibble, I think they accepted that there must have been something faulty with mine as it had had so little use and a replacement was with me on Thursday. Just fitted it and it is now working - at least I think it is. Just done the first print and everything seems to be there. Won't know for certain until I wash the parts but it looks better than anything I've had in the past 3-4 months so fingers' crossed. Changing the screen was a real faff though. It looks easy enough on YouTube and indeed it would have been, were it not for the fact that some resin had gotten into the edge between the frame and the screen which meant that when I tried to lift the screen out it completely delaminated and I took about 6 layers of LCD screen off one at a time! Thanks everyone for your advice. Edited July 25, 2021 by Chewbacca Link to comment Share on other sites More sharing options...
Chewbacca Posted July 27, 2021 Author Share Posted July 27, 2021 Just to follow up on my earlier post. Pleased to report that everything is working fine - indeed this latest print round is better than I have ever achieved before! 1 1 Link to comment Share on other sites More sharing options...
paulyoung666 Posted August 3, 2021 Share Posted August 3, 2021 (edited) Good stuff , the only thing I would add is that your layer times seem excessive , I’m using WWR with a Mars 2 and about half the time works fine 👍 Edited August 3, 2021 by paulyoung666 Typo 1 Link to comment Share on other sites More sharing options...
bootneck Posted August 3, 2021 Share Posted August 3, 2021 looking at that old screen glass, there shouldn't be any residue whatsoever on it. The amount of saturation shows either a leaking FEP or there is too much suction when the plate lifts. The suction would cause the FEP to get pulled up with the plate and then snap back when released, causing the resin to splash out of the vat. Just a note, never let any fluids - resin, cleaning fluid or anything else find their way into the seam around the screen as that will find its way onto the LED and that can become an expensive repair. If resin does find its way onto the screen, clean it off immediately. If it has dried like on your photo then it can easily be removed with a new flat blade. I use a new No.9 scalpel blade for this as it glides across the screen smoothly and removes any dried resin. I also leave resin in the vat for long periods and that is fine if there is absolutely no UV exposure; I plave a pillowcase over the printer when it isn't being used and that keeps all UV out and the resin fluid. Don't forget that in daylight, UV can start acting on the resin in the vat even in the short period whilst the door is open whilst removing the plate and printed item. If I am printing during daylight then I keep all doors closed and windows fully curtained. HTH, Mike 1 Link to comment Share on other sites More sharing options...
darthspud Posted August 3, 2021 Share Posted August 3, 2021 Home casting, what's required? not 3d printer Link to comment Share on other sites More sharing options...
bootneck Posted August 3, 2021 Share Posted August 3, 2021 Hi Darthspud, that is a totally different medium and methodology. Rather than divert this thread, I recommend that you ask the question in the CASTING FORUM. Check out the threads already in there, otherwise I'll be pleased to give you some answers to any questions you have. See you over in the casting forum. Mike 1 Link to comment Share on other sites More sharing options...
Chewbacca Posted August 4, 2021 Author Share Posted August 4, 2021 Thanks all for your comments. On 03/08/2021 at 06:38, paulyoung666 said: Good stuff , the only thing I would add is that your layer times seem excessive , I’m using WWR with a Mars 2 and about half the time works fine 👍 Interesting. The times I am using I think I took from Elegoo's recommendations with a very slight increase on first layer time following a few early failed prints. It all seems to be working fine now with those settings 22 hours ago, bootneck said: looking at that old screen glass, there shouldn't be any residue whatsoever on it. The amount of saturation shows either a leaking FEP or there is too much suction when the plate lifts. The suction would cause the FEP to get pulled up with the plate and then snap back when released, causing the resin to splash out of the vat. Just a note, never let any fluids - resin, cleaning fluid or anything else find their way into the seam around the screen as that will find its way onto the LED and that can become an expensive repair. Unfortunately that was exactly what happened. I developed a pinprick leak in the FEP about 4 months ago and got some resin on the screen. I thought I had cleaned it all off but clearly some did get into the seal. 21 hours ago, darthspud said: Home casting, what's required? not 3d printer Tried that once. Total waste of time which was why I went down the 3D printing route though I do concede that for some things (and people with the right skills) it does produce some good outputs. When the printer works I am getting far better results with that than I would ever get with casting, especially as some of the things I am printing are one-offs so I'd still have to create the master. For example I think casting would struggle to produce this dockyard crane job (for context, in 1/350 scale it is about 65mm long) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now