I love printing round disks on FEP... but time to move on

[The_Resinator]

did you the "dry run" test? is z-axis moving up during the print time?

yes the plate initially lowers on the z-axis (cant move paper sheet) , raised, lowers again (but the papersheet is now stiff but moveable), raised etc

Tonight's test print, I used silicon lube on the FEP.  Failed again - disks on the FEP once more.

why wont it print onto the print plate. I am only printing the example rooks straight from the memory stick.

I am using Elegoo photopolymer resin, UV wavelength 405nm,  made 2019/07/22, at room temperature 22'C

I am test printing on the stock tank with original FEP and also using a third party plastic tank

looking at it logical.. 

- it prints disks on the FEP every time - so the pattern is being exposed underneath.
- the plate isnt touching the print. - but dry runs prove it is at paper holding position on the z-axis
- the plate isnt accepting a print - too smooth? - currently stock state as delivered 
- the resin isnt right? Ive tried two.
- initial exposure time should be longer? - currently stock time as delivered on thumbdrive

Help! this is driving me nuts

Mark

What are you using to clean your plate? I only ask because I have had a couple failed prints due to what I believe was a somewhat dirty plate. I started using Mean Green and while I like that for the basic clean, I prefer isopropyl for a final clean. Just a thought.

Thanks Resinator

My plate is cleaned with 99.9% IPA

I was cleaning my tanks for todays tests (yesterday I used silicon lube on the FEP)

The rook print started, Ive got a a fatter disk on the FEP of about 4mm 

Today I was going to move away from the rook and try a few supports with less initial mass area on the FEP

first I was going to closely examine the print plate to ensure its completely flat..

Any better suggestions?

Mark

4mm? that is really small, since the rook base 30mm in diameter. At no point does the model slim down to 4mm. I am wondering if there is an issue with the light/laser. When I have had failed prints, because they didn't stick to the plate, the complete diameter or outline of the model or supports was there and stuck to the FEP. Personally I would try another print file and see if it works or try to test the lighting (watch it try to print without the vat or plate). Not sure if Elegoo has any troubleshooting steps for light issues.

[fromFDMtoSLA]

i think, he is talking about the height of the disk (?)

[fromFDMtoSLA]

just found this in the Thingi- Elegoo-Group:

quote:
royski - in reply to Bloozrider
Oct 2, 2019
Folks on the subreddit have reported that this is often the case with the rook file preloaded on the USB stick. Looks like it was supplied with a bad file. The rook file downloaded from Elegoo seems to be fine.
end of quote

[Ghola]

Having the same problems as you, but I am less further along. I have 4 failed prints over the last couple weeks out of 4 attempts. So far I have re-leveled (try 2), changed the FEP (try 3), and tried PTFE oil (try 4), all with similar results. I have been alternating between the supplied Rook file and my attempt at the "Fillenium Malcon" from Thingiverse. Reading above, I think the next attempt will be:

1. Re-level again
2. Re-oil
3. Use downloaded rook file
4. Check exposure settings for first 1-2 layers

[fromFDMtoSLA]

any news here about the "round disk"-printing?

[cgrtist]

any news here about the "round disk"-printing?

So I have had this exact same issue, to the letter.  I decided to add 5 drops of oil to the bottom of the resin tank. I then rubbed it all around so that the entire surface was covered.

I may try another brand of oil or lubricant, but for now, I am using Hoppe's 9.


   

I hope this helps...

[Jupp3]

Here are few ideas based on own experiences.

Whenever the print platform raises during the first (slow) layers, do you get kind of "ripping" sound? If you do, this comes from print actually being stuck to the build platform, and being ripped off from FEP. This is perfectly normal, and generally a good sign.

Also note:
Sometimes it just might get ripped off more or less silently. Silence doesn't automatically mean failure.
You MIGHT get more quiet ripping noises after the slow initial layers too, but often, it's mostly silent. That's because resin sticks to FEP less, as the exposure time is lower.

The center of my current FEP film is kind of cloudy / white. Tried to wash it, but it doesn't seem to want to come off. After cleaning and drying, it also feels a bit sticky. If I print at this area, I usually get raft on the build platform, and "matching" disc at the FEP film. Seems that when printer switches to lower exposure times, the area prevents resin from being properly exposed, so it doesn't stick to previous layer. Enough of these "partial exposures", and the resin hardens at the FEP film.

I can still print around the problematic area just fine. I'd recommend trying several models around the build platform at the same time, and seeing if any of them stick.

(And yes, I HAVE ordered replacement FEP films, but postal service during these times, you know...)

Also note that different resin types have different recommended exposure times. I had trouble with maroon red not sticking after the "slow" layers, but that was due to it needing longer exposure.

If you're printing models, that are completely supported "in air", and paranoid about failures, I recommend making a note of layer, around which the actual model starts, then pause the print BEFORE that, then you can see, if the supports are there. You can pause the print "during model" too, but sometimes you get visible lines to the model. Doesn't matter if the lines are only in the supports.

[kingranger]

a) Put RainX on FEP (sounds plausable)
I cant find my RainX, is there something else I could use (someone mentioned wd40?) - wont these additives contaminate the resin?...

b) Reset Z=0.. but this is an unexplained process and I understand I could break my screen. (also sounds plausable)
I wonder could someone point me at the link to the Z=0 reset process and how I will avoid breaking my printer

c) Change my printer exposures (need idiots guide to how and where..)

[...]

PS I saw that if I registered with Elegoo they would sent me some FEP sheets (usefui!)..cant find this link anywhere now... darn confounded internet...

I've only had my Elegoo Mars since about October but here are some things that have help me with successful prints:

- I use PTFE oil on both sides of the FEP film. It's basically teflon so it doesn't affect the resin. Just makes the surface non-stick. I apply it with a lint free paper towel or micro fiber towel.

- Using the Z = 0 button. So basically what you do is this: Level your build plate as you would normally (i.e. unscrew sets screws, lower build plate onto paper, etc etc). After you have leveled the build plate, switch to the smallest increment (should be .1mm) and raise the build plate by .1 - .2 mm. Then press the Z=0 button. This zeroes the build plate to the current z position for your build plate. This was probably the biggest helper for me right after this next thing I'm about to mention

- The surface of the build plate. Which build plate do you have? The original black surfaced one or the new bare metal one? IF you answered the black one, then you have the same one I had originally received. In my opinion this thing was way too smooth and I believe that it's because of the smoothness that Elegoo switched to the new bare metal build plate that they are now selling separately on Amazon. In fact when I contacted Elegoo about my build plate (which I had scratched with a metal scraper), they sent me the new one. Sorry got off topic, so what I did to the original build plate to help adherence is used some 320 grit sandpaper and lightly sanded the surface in a circular motion from the center out. Just enough to give the surface a little added 'tooth' for the resin to stick to. It's not enough to stick the build to the plate like super glue or anything, though. Otherwise, buy the new build plate or contact Elegoo about sending you a replacement. You've only had this thing for about 4 months right? Elegoo has been extremely generous with helping me get my machine up to the specs of the most recent release.

- Make sure to use the settings for the specific resin you are using. I use mostly Siraya Tech resins and they seem to cure faster and more faithfully than the Elegoo stuff so my exposure time is usually about 8s per layer or so vs the 14s I had to set for Elegoo clear green. You would change these settings in your slicer program like Chitubox but there is a way to change them during the print by clicking on the settings gear icon WHILE the print is printing. It gives to the option to change # of base layers, exposure times for base or normal layers, etc., but you have to be quick about it if you are planning for it to affect the print after you have started it. Also, changing it on the printer is annoying because you have to click on the value, then delete it by pushing the backspace button, then enter in the new value, and then the check mark icon, so I would just stick to adjusting those in the slicing program. 

Anyway, I hope some of this info helps you like it helped me and here is the link to the free FEP from Elegoo:
https://docs.google.com/forms/d/e/1FAIpQ...w/viewform