Stuck in a 3d rut..

[Bangseat]

Hi all,

 

I'm having a bit of a time of it with my Elegoo Mars, and wondered if anyone had some advice?

 

I've been having consistent failed prints for a couple of weeks now. In some cases half the parts haven't formed and/or stuck to the FEP. In some cases I have got the parts or most of them, but with significant deformation of some layers.

 

I have changed the LCD - that was due anyway, and changed the FEP twice. I regularly level the printer. I have tried brand new resin. And last night, I put it on thinking it must surely be perfect now...but no😒

 

Now I'm thinking peel force and ambient temperature. My print beds are quite busy. I have the first 12 layers on 90 sec exposure on my 'busy plate' setting, to try and ensure good adhesion as the first few layers are big chunks - typically 20 odd support bases, and this has worked well before. This, I am reading, means a large radius of build (well, multiple large radii), which will add to the 'peel force' (the yanking-Anthony-Quayle-in-Ice-Cold-In-Alex out of the quicksand force) which increases the chances of the layer staying on the FEP film or deforming. Viscosity may be a factor too. It was cold last night - freezing in fact - and it probably was in my attic too, so the resin was more viscous. (As as side note, I am hearing a 'pop' sound as the layer separates when I first turn on the printer).

 

The next step I suppose will be trying reducing the lift speed (which will slow down prints which are already running to 20 hours). But aside from scaling down operations until it warms up, I'm a bit stumped. 

 

Is 3d printing a seasonal activity?

[Alvaro Rodriguez]

Cold temperatures may have some effect on the prints but its impact may be relative and variable from case to case.

 

Fact is that the resin releases heat during the cure -it´s an exothermic reaction- and gets warmer -and with less viscosity- as long as the print run progress.

 

Leaving apart the enviromental factors, a few other ones may be preventing you from having a successful print run. For some troubleshoting some images of the object in the slicer and a screenshot of your printer settings would much welcomed me thinks.

 

Regards!

Alvaro

 

Edited November 23, 2020 by Alvaro Rodriguez

[Bangseat]

Thanks @Alvaro Rodriguez, will post some pics from Chitubox shortly.

[Alvaro Rodriguez]

BTW, and just for confirming, may I ask if the new replacement screen is sitting flush with the printer metal body as per the stock design or is it slightly below?

[hendie]

photos of the "significant deformation" would also help

 

I also have an Elegoo Mars, and I also hear the pop sound as the layer separates from the FEP.   I think that's more to do with the surface area in contact with the film than any particular stage in the process.

I have had a few failed prints, but have traced every one of those back to something I have done.  Just as an FYI, I level the build plate every time I remove it from the Mars

What thickness FEP film are you using?

[Bangseat]

@Alvaro Rodriguez - this is the print that has given me the most trouble:

 

 

@hendie thank you, I'll dig out the malformed pieces when I get a chance - the fuselage is the worst offender, bulging layers and some irregularities where longer supports meet the part. The FEP is Elegoo OEM, 0.15mm.

[Bangseat]

Hi @hendie, these are the layers I was talking about:

The grey is not completely unusable, but the clear is rather disappointing.

 

@Alvaro Rodriguez, I just checked the lcd, and it is pretty much flush, if anything slightly proud of the metal body. 

 

[hendie]

Are you using the automatic support feature in Chitubox?

I found that with the last update I need a lot more supports than Chitubox thinks I need in order to get successful prints.

What is the ambient temperature where you are printing?

@wellsprop had issues recently with temperature, so I wonder if he has any input on this?

[Bangseat]

Well, I don't have any definite data, but it there was a frost on Saturday night which means it would have been single figures in my loft. More supports is definitely an option - generally I am using auto supports and deleting some rather than adding. 

 

 

[Alvaro Rodriguez]

Hi!

 

Firstly, thank you for doubleckecking the LCD is sitting flush with the printer body. I asked that for a reason and it´s because LCD replacement kits -like the Elegoo one- use to have a tempered glass thinner than the original stock one. And while having a thinner tempered glass is not an issue -quite the oposite in fact-, that may lead to LCDs sitting a tad below the printer metal body. And that´s a serious issue always.

 

Secondly, and based on your images and previous comments, I would never -never!- rely on the auto support function. It´s not just that it´s not fault free it is also that uses to place less supports than required often. I´m for one thinking that it is always better to have one support more than a failed print.

 

Thirdly. looks to me your parts could be placed in the build plate with a more rational distribution. Any part placed in the certer is going to have more chances to print successfully than those in the perimeter. If you asked me I would put the fuselage in the center, surounded by the wings and after that I would place the rest of parts closer to the previous, avoiding the edges as much as possible. Note also that unless your printer had a led array UV lamp, the exposure is weaker in the edges too.

 

BTW, note that in RGB printers -like the Elegoo or the Photon and Photon S-, I use to have sharper details in everything paralell to the X axis than to paralell in the Y one or that´s my experience at least. Just saying in case you wanted to rotate your wings 90º for trying to have a more precise surface detail.

 

And a last note. Just for troubleshooting use a single and small -in height- part for a quick print run. There is no need to do a production print run for discovering everything is working -or not- as expected.

 

HTH!

Alvaro

 

Edited November 24, 2020 by Alvaro Rodriguez

[bootneck]

I had a problem with bulging on the fuselage and was recommended to add a few side supports.  There is a reluctance to add supports on the sides of fuselages, where it will show; however, these can be filed and cleaned off afterwards. 

I am also of the opinion that there needs to be more supports up towards the tail on your fuselage, otherwise you are likely to get a droop effect which would push out the sides.  Think of the effect as bending a kitchen/toilet roll cardboard  tube.

Chitubox has a facility to show where the supports are needed by highlighting the areas with white dots and red colouring.  The deeper the red colour, the more supports or even thicker supports may be needed there.  I'm sure that you already knew that but I've posted this in case any beginners are reading this also.

 

View of an over accentuated layout to show the white markers where supports are needed.

 

Inverted view showing the red areas that need special attention on supports. Note the supports are on Medium setting - probably double would be needed if set at Light supports.

 

cheers,

Mike

[Kushan_Farsight]

your lifting speeds on the z axis seem very quick compared to mine. have you considered trying to lower them?  i think i use around 25mms. 

[Alvaro Rodriguez]

58 minutes ago, bootneck said:

There is a reluctance to add supports on the sides of fuselages, where it will show; however, these can be filed and cleaned off afterwards. 

 

Indeed! 👍 We all love to have our printed parts in pristine condition out of the build plate... but it is supposed that removing a print support never should be a problem for a modeller that has been removing kit parts from the sprue trees for a life! 😅😆

[wellsprop]

The photo of the clear part looks like the issue I had when there were too few supports. 

 

You mention frost, I had lots and lots of problems printing at temperatures below 15 degrees.

 

Im unsure about the ridges on the grey parts. It almost looks like the print plate isn't raising perfectly vertically (but this is speculation). 

[Bangseat]

Guys, thank you so much for the advice. Alvaro, Mike, yes I should bite the bullet and add more supports. It is a job to clean, apart from sanding they often need filling where breaking off the support takes off a bit too much resin, but as you say, better that than a failed print. And it makes perfect sense to print bigger parts more centred. I am on the old model Mars with a simple UV light source. 

 

Will report back!

[Alvaro Rodriguez]

7 hours ago, Bangseat said:

they often need filling where breaking off the support takes off a bit too much resin

 

Ensure you to use a ball tip in your supports trees for avoding them taking off any resin from the printed part.

 

Decide a ball diameter according to your needs and the end of the conical section of the support and insert it halfway into the model.

 

You will see that when removing the support trees those use to break at the start of the ball tip often.

 

The result is that you will have to remove any remains of the protuding half ball in the printed part later but that´s much easier than filling holes left by any support with pin type tip.

 

Regards!

Alvaro

 

 

Edited November 25, 2020 by Alvaro Rodriguez
Added reference image

[Blacktjet]

Just to jump in here with a suggestion ( there are far more knowledgeable people on here with technical advice). When I started printing with my Photon S, I was getting failed prints regularly. It now seems that I have found the sweet spot as I have zero failures. First of all, I stopped printing below 0.050, the difference is not that noticeable and the more layers you have, the more chances there will be for something to go wrong. Secondly, when ever possible, print directly on the build plate and just add supports where necessary.

 

These are my settings:-

Layer height 0.05 mm

bottom layer count is 3 - 6

bottom exposure time is 95 s

layer exposure time is 18 s

Light-off delay 6.5 s

Bottom light-off delay 3 s

 

Everything else is the same as you. Hope this helps.

Edited November 27, 2020 by Blacktjet

[Kushan_Farsight]

On 11/26/2020 at 10:26 AM, Blacktjet said:

Just to jump in here with a suggestion ( there are far more knowledgeable people on here with technical advice). When I started printing with my Photon S, I was getting failed prints regularly. It now seems that I have found the sweet spot as I have zero failures. First of all, I stopped printing below 0.050, the difference is not that noticeable and the more layers you have, the more chances there will be for something to go wrong. Secondly, when ever possible, print directly on the build plate and just add supports where necessary.

 

These are my settings:-

Layer height 0.05 mm

bottom layer count is 3 - 6

bottom exposure time is 95 s

layer exposure time is 18 s

Light-off delay 6.5 s

Bottom light-off delay 3 s

 

Everything else is the same as you. Hope this helps.

Can you tell me what color/make of resin your using?

I am using a Plant based Clear resin by anycubic on my standard Photon, but your timings are quite a bit different to mine (65s bottom exposures, 8.5s layer exposures, 0.5s light off) However i AM still getting some failures. seeing the large difference between our exposure times, perhaps i need to be giving it a bit more time to cure and a little longer light off time. 

[Bangseat]

I'm very grateful for all suggestions, thanks folks. 

 

I think the range of suggestions points to the possibility that it is not one thing that is going wrong, but a myriad of interconnected things. Just like when the mechanic looks at my car...

 

I did clock @wellsprop's genius idea of the reptile mat on another thread. It makes sense that, even if resin warms up as the print goes along, it you start with very cold resin the first few layers are going to be unreliable. So I put one on the Mars, let it warm through for an hour or so, printed and today got a successful print. It was a simple piece though. I've put on a complex print tonight, with lots of support and arranged a hopefully a bit better as per Alvaro's suggestion, so we'll see tomorrow night...

 

@Blacktjet, those are long exposure times - double mine - but it clearly works! I have had perfect success at 9 secs in the past, so I really want to reclaim that...

[general melchett]

My tuppence worth, Bangseat, I'd definitely recommend adding supports manually and not relying on auto supports as I find they're rarely where I really need them. I've found Chitubox can be a pain with frequent CTDs, especially the latest iteration, v 1.7.0 (I always save the file before attempting to play around with the supports, it saves you a lot of aggravation). I'm currently swapping over to Lychee pro and PrusaSlicer as I prefer their support systems and stability.

 

Temperature is also a big factor, I had similar issues when first using the Epax X10, 4K mono, which was down to the location of the printer, (unheated back room in attic, due to it's high fan noise). Since relocating it to a thermostatically controlled room (+25°C ) the prints have been perfect. The resin should run freely, obviously, when cold, the viscosity increases which can lead to print issues. I use Phrozen water washable ABS-like Grey model and Elegoo water washable Rapid Resin Grey for most printing and Epax Hard and Tough and Esun Clear for more specialised jobs and find that all work well in the right conditions. I also have three Mars 2s and two Mars Pros in the mancave, all lined up along a radiator, (vented externally) running at approximately 22-25°C , again, no issues. The mat idea is a good one and something we're looking into, ourselves.

 

Can't comment on the Mars settings as I don't have one, but one thing I can say...overlong exposure times, particularly Bottom Exposure Time, will lead to a shortened LCD screen life.  

 

Apologies if this has already been posted,

 

Cheers all

 

 

[LorenSharp]

1 hour ago, general melchett said:

My tuppence worth, Bangseat, I'd definitely recommend adding supports manually and not relying on auto supports as I find they're rarely where I really need them. I've found Chitubox can be a pain with frequent CTDs, especially the latest iteration, v 1.7.0 (I always save the file before attempting to play around with the supports, it saves you a lot of aggravation). I'm currently swapping over to Lychee pro and PrusaSlicer as I prefer their support systems and stability.

 

Temperature is also a big factor, I had similar issues when first using the Epax X10, 4K mono, which was down to the location of the printer, (unheated back room in attic, due to it's high fan noise). Since relocating it to a thermostatically controlled room (+25°C ) the prints have been perfect. The resin should run freely, obviously, when cold, the viscosity increases which can lead to print issues. I use Phrozen water washable ABS-like Grey model and Elegoo water washable Rapid Resin Grey for most printing and Epax Hard and Tough and Esun Clear for more specialised jobs and find that all work well in the right conditions. I also have three Mars 2s and two Mars Pros in the mancave, all lined up along a radiator, (vented externally) running at approximately 22-25°C , again, no issues. The mat idea is a good one and something we're looking into, ourselves.

 

Can't comment on the Mars settings as I don't have one, but one thing I can say...overlong exposure times, particularly Bottom Exposure Time, will lead to a shortened LCD screen life.  

 

Apologies if this has already been posted,

 

Cheers all

 

 

To my dismay I followed online chat  "Experts" on increasing exposer time when I had problems with print failures. Turned out the LCD screen was starting to fail and that hastened it's demise. The Youtube poster 3DPrinterPro Had excellent advise on settings as you have seen from the above. He also has a video explaining the merits of the light off and bottom light off delay settings and how to adjust them. I'm hoping it helps with extending the life of the LCD screen. So far prints like a charm. Something I've also done is create a dummy object to check my screen for dead spots.. With the vat and build plate removed I load the object which is nothing more that a flat plate the size of the LCD screen and I place a sheet of paper over the screen and start the print. as the LCD shines if there are any dead spots on the screen they will show up, IT will also point out weak areas of brightness that can effect a print. This would be  more of an issue with a color LCD screen as opposed to a monochrome screen. But until I can scrape together the funds for either a Mars Saturn or EPax E10 I wouldn't be able to certify this.

[general melchett]

Totally agree, 3DPrinter Pro has some very sound advice, watch his video on lift heights. Looked at a Saturn but right now I'm very pleased with the X10s performance (it's not cheap but the results speak for themselves), in fact we'll probably get another in the New Year as we need reliable volume production. The mono screens really helps with build times as I print at 0.3 most of the time, depending on the object, same with the Mars 2.

 

I've also printed off a test-piece for calibrating the correct exposure times using this tool.

 

 

 

[LorenSharp]

General, have you noticed if the E10 allows for greater fine detail on objects? With the Mars I've found that anything below a diameter of 250um is a tossup as to being printed. It takes longer but I'm usually running .01-.015 layer height.

[general melchett]

I'm not sure about the E10 but with the X10 the detail is excellent at .03, I haven't tried printing at .01 as yet. The main attraction of these mid-range printers is the build-plate area (three times that of the Mars Pro) and 8.9'' 4K mono screens for increased build speeds. Also, I agree, anything below 250um, at .03 anyway on the Mars 2, doesn't always print. Which Mars are you using?

[LorenSharp]

Just a good old basic Mars. Got t back in the Spring. Ahhh typo, ment X10. With the success of using the Mars, I've been leaning towards getting the Saturn, when and if it ever becomes available. But a larger Build plate is a definite must. If anything to be able to build larger parts or in fact an

Aircraft  by sections.. It's possible with the Mars but I would have to break the constituent parts down further that would be practical. The evils of working in 1/48. Have you had any success in printing clear canopies? That will be my "Holy Grail".