Sci-Fi modeling on Elegoo Mars -- Community support/tips
- Thread starter Hunk a Junk
- Start date
So I've been having print failures on my Mars where the resin is sticking to the bottom of the print vat instead of the build plate. This resulted in the resin slightly warping the FEP film due to the exothermic reaction of the curing resin... Is my FEP wasted? The imperfections are slight but there.
Why is the resin sticking to the FEP, and how do I avoid it?
On a positive note - I was able to print Studio Kitbash's Entex wankle transimission on my FDM printer! But I'm still having issues with the Elegoo...
Thanks,
Jedi Dade
Why is the resin sticking to the FEP, and how do I avoid it?
On a positive note - I was able to print Studio Kitbash's Entex wankle transimission on my FDM printer! But I'm still having issues with the Elegoo...
Thanks,
Jedi Dade
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I'm having the same issue occasionally on my Photon. It seems to be a badly calibrated build plate (too far off the FEP film). Removing the cured resin results in small dents sometimes, but I haven't found them to be much of a problem. But it depends on the amount I guess.
BTW, the resin always sticks to the FEP film when curing AFAIK, it only sticks _better_ to the build plate or previous resin layer and fuses with it. That's why the build plate needs to drive relatively far upwards after each layer, to detach the cured layer from the film. Otherwise, it would just warp the FEP film upwards a bit more after each exposure and +z-step, until something rips off...
BTW, the resin always sticks to the FEP film when curing AFAIK, it only sticks _better_ to the build plate or previous resin layer and fuses with it. That's why the build plate needs to drive relatively far upwards after each layer, to detach the cured layer from the film. Otherwise, it would just warp the FEP film upwards a bit more after each exposure and +z-step, until something rips off...
Hmmmm... I followed the directions on setting the build plate Z height... and the test print went perfectly fine. it was only when I switched to a model that I tried to slice with chitubox that I had an issue. I suppose I should load the test model and check the settings against what I had on the model that I sliced... and check the Z step for the pull away. maybe its too high/low to get the addhesion / separation from the FEP plate. Something to try at any rate.
Jedi Dade
Jedi Dade
TazMan2000
Master Member
thorst & Jedi Dade , could you post a pic on how you have things sitting on the build plate in Chitubox? You want as much surface contact to the plate as possible.
I had similar issues. Hopefully your build plates are sanded down to bare metal. You probably don't have to replace your FEP film. When you level your plate, are you checking if the paper still fits under each corner of the plate with about the same force? If not, re-adjust the level and perhaps use a thinner piece of paper. I don't particularly like the old plate adjustment. I've heard that there is a new one out that works much better.
https://www.amazon.ca/ELEGOO-Buildi...1&keywords=elegoo+tanks&qid=1590621416&sr=8-4
Surprise surprise...bare metal on the bottom.
Take your Resin Tank out and clean it well. Use a soft cloth and Windex to clean out all traces of resin. The film may be a bit wavy, but it should not have scratches in it which will look like fog, limiting the amount of UV light to the resin.
Apply a thin coating of silicon oil, (I use Tri-flow) and polish it until it dries. It should dry clear, but will prevent the resin from sticking to the inside of the film. Once dry it will have little if any effect on the resin.
Use the yellow plastic spatula to remove the stuff bonded to the film. Lightly press your finger to the bottom part to disbond the cured resin from the film. I'm sure you know to be extra careful not to put any holes in the film.
I bought a 2-pack of plastic resin vats off of Amazon which had the FEP films installed. Try that as a last resort.
TazMan2000
I had similar issues. Hopefully your build plates are sanded down to bare metal. You probably don't have to replace your FEP film. When you level your plate, are you checking if the paper still fits under each corner of the plate with about the same force? If not, re-adjust the level and perhaps use a thinner piece of paper. I don't particularly like the old plate adjustment. I've heard that there is a new one out that works much better.
https://www.amazon.ca/ELEGOO-Buildi...1&keywords=elegoo+tanks&qid=1590621416&sr=8-4
Surprise surprise...bare metal on the bottom.
Take your Resin Tank out and clean it well. Use a soft cloth and Windex to clean out all traces of resin. The film may be a bit wavy, but it should not have scratches in it which will look like fog, limiting the amount of UV light to the resin.
Apply a thin coating of silicon oil, (I use Tri-flow) and polish it until it dries. It should dry clear, but will prevent the resin from sticking to the inside of the film. Once dry it will have little if any effect on the resin.
Use the yellow plastic spatula to remove the stuff bonded to the film. Lightly press your finger to the bottom part to disbond the cured resin from the film. I'm sure you know to be extra careful not to put any holes in the film.
I bought a 2-pack of plastic resin vats off of Amazon which had the FEP films installed. Try that as a last resort.
TazMan2000
I leveled the printer build plate with a piece of printer paper that was covering the entire UV screen. the build plate has 2 adjustments screws that were both loose, I squared up the plate after it was in contact with the paper on the UV screen, and tightened the Hex allen set screws. Which is how I did it for the successful print of the test rooks. I suspect its something mucked up in the slicer settings... I'm going to dig into that on Friday - which is my next day off...
Jedi Dade
Jedi Dade
Hunk a Junk
Sr Member
My Mars has arrived! I have it unboxed, but it's going to be another couple of days until I have the time to really devote to getting it set up and do a couple of test prints. It's so purty...
Just pulled these off my Mars this morning. For my 1/48 Y-Wing. I waaaaaay overdid the supports on the canopy because it's a very delicate part, and because I didn't want it warping at all.
I'm pretty happy with these prints, because I have been having a lot of failures the past few weeks. My Z-Axis rod was grinding, and that was causing my prints to fail. So I cleaned off the rod, and applied some white lithium grease to it, and now it's good as new. Just for those who have a similar issue (My Mars is about 5 months old now). Just FYI.
SB
I'm pretty happy with these prints, because I have been having a lot of failures the past few weeks. My Z-Axis rod was grinding, and that was causing my prints to fail. So I cleaned off the rod, and applied some white lithium grease to it, and now it's good as new. Just for those who have a similar issue (My Mars is about 5 months old now). Just FYI.
SB
Fett_Ish
Sr Member
I’m gonna hold out and go for the Saturn I think, but it all depends on ow well this one works for you. So don’t mess up!
If none of you have replaced your FEP yet, I just did mine yesterday. Elegoo has a great video on YT. Took about 20 minutes, and my test print came out perfectly. Easy peasy.
SB
SB
Got my Mars a few days ago now and have been doing a few test pieces. I learned the hard way that if you set the layer height to 0.01mm (because I my head I wanted it to be as high resolution as possible) it takes FOREVER to make anything. And I expect that the detail is no better than if you set it at 0.05, given the resolution of the actual model.
I have a question re orientation of models on the print bed (I have tried to google this and didn't seem to find anything very convincing). If I'm printing something which is 100mm tall and 10mm wide, is there any disadvantage to laying it down flat on the print bed? Logic tells me that this will make it print much faster, as 10mm splits up into a lot fewer layers than 100mm... If there is a large flat surface being printed will it be much more prone to sticking to the FEP? I notice Tazman200 said that you actually want as much surface area contact as possible?
I have a question re orientation of models on the print bed (I have tried to google this and didn't seem to find anything very convincing). If I'm printing something which is 100mm tall and 10mm wide, is there any disadvantage to laying it down flat on the print bed? Logic tells me that this will make it print much faster, as 10mm splits up into a lot fewer layers than 100mm... If there is a large flat surface being printed will it be much more prone to sticking to the FEP? I notice Tazman200 said that you actually want as much surface area contact as possible?
TazMan2000
Master Member
You can print it flat, but don't forget the supports. Unlike FDM where the extruder has to lay out the filament everywhere that it needs to, and can varying times depending on the LxWxH of the object and its complexity, a MSLA printer does one layer at a time for a specific time, regardless of the size of the object (it has to fit on the build plate of course). Whether you are printing out something the size of a brick or the Eiffel Tower of the same height, it will take the same time. Ensure you have enough resin and you monitor it when printing something large and hollow it out if possible.
There may be distortion or disbonding of some parts from your supports. Initially this was a big problem for me. Support is the key. If you are printing out something perfectly flat on one side, it is easy to make that your contact point on the build plate, if it has enough contact area. If there is not or the object is complex, support will of course be needed. Support placement is critical, and while Chitu does an ok job of placement, it is just a program and can't think. Think of the support as being the shaft of an umbrella. Stick that umbrella in a pool and move it up and down in the water and you can imagine what stress that thin resin support has to tolerate going in and out of the vat a few thousand times. Now imagine if the skin of the umbrella was 0.05 mm thick.
When I print with the Elegoo brand resin, breaking or cutting off the supports leaves scars or chunks out of the printed object. I can't comment on different brands, but I'm assuming that is the case with most resins. I think they make a PVC like resin, but from what I have seen online, its not the greatest and it is significantly more expensive. So again, support placement is critical (as well as object placement) to hide the support damage and reduce the amount of time for filling and sanding.
Your object shouldn't stick to the FEP if there is significant contact to the build plate, and if the build plate is correctly adjusted. Think of the system as double sided tape. If you separate object joined by double sided tape, its going to stick to the side that has the best material and contact for adhesion. If your build plate is too high the resin will not cure to it, but against the FEP. If it is too low, then you are smashing the layers of partially cured resin against your LCD and FEP.
TazMan2000
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TazMan2000
Master Member
For a tall and thin object, you could try and import the STL into TinkerCad and add in a thin baseplate for greater contact area, but if there is significant undercuts Chitu won't be able to add in the proper supports.
TazMan2000
TazMan2000
There is a great set of tutorials for setting up supports made by 3Dprintingpro on youtube. he has several tips that should help with the removing of chunks from the model when removing supports. I've also found that adding "heavy" supports along side the "light" supports increases the likelihood that the supports will print properly so that they don't fail along the way and actually support the model - increasing the chance of successful prints. But I'm still a noob - just thought I'd share a trick I learned.
Jedi Dade
Jedi Dade
xeno
Sr Member
The layer lines you speak of, you get when a flat surface is placed a few degrees from 90 degrees, you get stepping/banding, that's why you want to put most models at an angle, to prevent some surfaces to get the stepping.
You can see the stepping, when you have a rounded surface, some parts will show this stepping.
You can eliminate most if not all stepping by using anti aliasing in the settings of your slicer. (if your printer supports it)
This image shows the ideal angle per layer height resolution, but is ideal for a square, but can be diferent for a figure, just something to think about when angling a model in the slicer.
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This is really useful. I've seen other people saying that you should definitely turn off anti-aliasing, or that it won't work unless you have a really powerful CPU on your computer anyway.
I've been doing a bunch of test-prints and having some great results as well as some not-great results. One issue I've had is trying to print some small figures - the models are hollow but when printed the walls are so thin that they just fall apart. I've tried "infilling" the model using Chitubox but the infills that Chitubox seems to be capable of are too large-scale, and don't support the smaller parts of the figure on the inside. So I thought I would try another slicer programme, but couldn't find one that caters for resin printers. Prusaslicer and Cura both seem to only cater for filament printers?
The other problem I've had is that on the "top" side of my prints (i.e. the side which has all the supports attached to it) I get a lot of deformation of the resin, as if it has pooled around the supports and partly cured before the print finishes. Is this something that can be prevented, or do I just need to deal with it after printing?
FYI I am using Elegoo's water washable resin, as I really don't have space or the desire to deal with really noxious resins, alcohol baths etc etc. If the normal resin would be better then I probably need to rethink this. I've also had a few problems with prints not curing properly - I imagine this could be solved if I bought a UV oven type thing, but again I have no space for that so will maybe have to just wait to print stuff until it's a really sunny day!
Apologies for asking a million questions and not giving much back in terms of answers or help! I've tried to find answers to this stuff by googling and am having not a lot of success.
I've been doing a bunch of test-prints and having some great results as well as some not-great results. One issue I've had is trying to print some small figures - the models are hollow but when printed the walls are so thin that they just fall apart. I've tried "infilling" the model using Chitubox but the infills that Chitubox seems to be capable of are too large-scale, and don't support the smaller parts of the figure on the inside. So I thought I would try another slicer programme, but couldn't find one that caters for resin printers. Prusaslicer and Cura both seem to only cater for filament printers?
The other problem I've had is that on the "top" side of my prints (i.e. the side which has all the supports attached to it) I get a lot of deformation of the resin, as if it has pooled around the supports and partly cured before the print finishes. Is this something that can be prevented, or do I just need to deal with it after printing?
FYI I am using Elegoo's water washable resin, as I really don't have space or the desire to deal with really noxious resins, alcohol baths etc etc. If the normal resin would be better then I probably need to rethink this. I've also had a few problems with prints not curing properly - I imagine this could be solved if I bought a UV oven type thing, but again I have no space for that so will maybe have to just wait to print stuff until it's a really sunny day!
Apologies for asking a million questions and not giving much back in terms of answers or help! I've tried to find answers to this stuff by googling and am having not a lot of success.
