First layer doesn't stick.  

RE: First layer doesn't stick.

before the next print, could you either wash the print surface with 99.9% IPA and a clean, plain paper towel. scrubbing the surface to ensure cleanliness.

Or, (this next suggestion always causes adverse comments)  would you be prepared to wash the build plate, with HOT WATER and dish detergent, then rinse well, (I use a green scotchbright pad to scrub the build plate surface)  and dry the build plate thoroughly  with a plainpaper towel

when you calibrate the tilt mechanism, you may have stopped raising the bed a little early.   would you like to try re adjusting the initial configuration?

have you also tried increasing the "Initial Exposure time"?   so that the first layers cook a little longer? 

Have you selected the correct resin profile?

regards Joan

RE: First layer doesn't stick.

anyone tried a piece of PEI sheet on the plate ?

RE: First layer doesn't stick.

Posted by: mark.w2

anyone tried a piece of PEI sheet on the plate ?

Does this apply to the SL1?

RE: First layer doesn't stick.

I'm curious if it would work

will try it when my kit eventually gets here

RE: First layer doesn't stick.

Hi Mark, Bobstro, 
the process for Resin printing and FDM is different, 

resin printing relies on each succeeding layer gluing it's self to the previous layer, or in the case of the first layer, gluing it's self to the build plate

I don't think there has been enough experimentation to confirm the benefits of  surfaces such as PEI. 

surprisingly I haven't seen suggestions of Glue stick, painters tape, or hair spray...   YET!

reading about other printers, I have heard of flexible build plates...

The SLI takes us back to the era of the Mk1 & Mk2 printer when we had to 'chisel' the prints off the build plate... 

 for me, increasing the first layer exposure time improves the potential for bonding to the build plate, and making the build plate perfectly clean,  improves the chance of the resin bonding to the build plate! 

when the printer is working well, you get a sort of 'Plunk' noise as the FEP Film pulls/peels off the resin layer at each tank tilt, which ends the previous layer exposure cycle. the FEP is like a drum skin and the movement of the fep film parting from the previous layer is 'damped' by the resin in the tank...

regards Joan

RE: First layer doesn't stick.

I've got a few other SLA printers so am used to the adhesion issues.

I was swapping a build plate over the other day on a mk3 & thought.. I wonder if PEI is a better surface for resin than the metal plate..

definitely something I will be trying out soon, now that I finally got my shipping notice, I have plenty of spare PEI sheets from my mk2 days

only risks I can see, the resin either wont bond to PEI, or it will bond too well..

other slight risk I suppose, the pulling force between the plate & FEP might be too much for the glue on the back of the PEI (think bubbles on the mk2 bed...)

btw Joan, I have found these thin spatulas are much better than the thick kind that most people use, haven't had a print yet on my other machines that I couldn't remove easily with these, I don't even bother taking the build plate off, just a gloved hand to catch the print & slide one of these under it & it pops off every time.

https://www.amazon.co.uk/gp/product/B073QHJSMW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

RE: First layer doesn't stick.

Hi

Like Brandon I have the exact same problem. My first layer just wont stick to the build plate (It always sticks on the FEB). I tried everything recommended in the printing guide. I repeatedly recalibrated the whole printer. I tried different prusa resins. I tried different curing times (35, 45, 60, 70) for the first layer. I cleaned everything with soap, with ipa, with water. I tried with a heating source for optimal resin temperature. I tried printing presliced model which are on the printer and also one i sliced myself. All this with no success. I am starting to loose my mind over this, since I can't think of anything else to try out. 

Can anybody help me out here and suggest something to try out?

Thanks in advance,

Nicolas

RE: First layer doesn't stick.

@nicolas-s6

So I had same issues, 3 days I could not print anything, then support helped me. Seems I did not screw one of the screws that is holding the FEP film down all the way and that is why my VAT was a little higher. Turn your VAT upside down, and use a small ruler or something straight to check that all screws are lower than the FEP film

RE: First layer doesn't stick.

@dario-f

Thanks for the reply. I did check that and everything was ok. 

I actually got everything to work now. In the end I think it was a calibration problem. I think i moved the printer after I did the first calibration and then never recalibrated the position of the build plate relative to the VAT. I guess there was something off there and therefore the print always stuck to the VAT.

Thanks anyway!

Nicolas

RE: First layer doesn't stick.

I had similar problems aftr 2 weeks of building and printing on my SL1. After four or five failed prints, I was flummoxed. I had re-calibrated three times. Cleaned out the tank, washed it with soapy water. Other people say wash it with IPA. I had 9 good and one half-good prints so far.

I finally bit the bullet and replaced the fep sheet in the tank. First print is perfect. When I examined the fep closely, it has minute crease-like marks, as if I caught it with my fingernail. Reading the other thread on the fep life expectancy, I may have to figure another 50 pence per print into my costings. I've now ordered another 5 sheets from Prusa.

At least it's only a half-hour job, unlike replacing the PEI layer 🙂

RE: First layer doesn't stick.

Hello,

in the last few weeks the printing was everything fine. Because the old FEP film is not so clean anymore, I change a new one. But since then I always had the probelem,that the first layer can not stick on to the plattform. I recalibrated and checked the screws. Could it be any other reasons?

Thanks in advance for your help.

Sijia

RE: First layer doesn't stick.

After a couple of weeks with the SL1, I am also experiencing problems with the first layer. I have about 50% chance of getting the first layer to stick to the build plate. I have tried all the tips mentioned earlier (including the scotchbright pad scrub), but still no improvement.

The I started thinking (yes, that is dangerous, I know). It is only the first layer that is the problem, at least for me. If that sticks, then the rest of the print usually goes well. So why not make the build plate out of a material that works: The resin itself. So now I am testing this method:

1. Prepare a print session as usual.
2. Put a little resin on the build plate. Just a few drops.
3. With a paper towel or a scraper, smear the resin out on the plate. Make a very thin layer all over the build area.
4. Cure the layer with UV light. I use the CW1 for one minute.
5. Put the build plate back in the SL1 and start printing.

The idea is that now the first layer will stick to the thin layer of cured resin, and that will make a stronger bond than to the FEP film. I don't have enough prints to statistically say this is a better method, but it seems to work fine so far.

RE: First layer doesn't stick.

@ejberg

That's an innovative thought. Please do let us know how this method works after some more prints.

RE: First layer doesn't stick.

Posted by: @andrew-h46

Please do let us know how this method works after some more prints.

I am back with good news. Now, after a handful of prints, I can say that this is working really well. I have not had a single failure after I started to "prime" the build plate with a thin layer of semi-cured resin.

I am still working on how to clean the plate after printing, as the thin layer is left behind where there were no printed parts to be scraped off.

RE: First layer doesn't stick.

Perhaps you can leave the thin layer on the plate. Until it builds up thick enough to remove or stops working.

RE: First layer doesn't stick.

@ejberg

THANK YOU, THANK YOU, THANK YOU! ... After several failed tries with the first layer not sticking to the platform, this was the only solution for me! it worked on the first try!  I also have to recalibrate the printer almost every time I use it .

Thank you for sharing....

RE: First layer doesn't stick.

I too was having trouble with prints sticking and was on the verge of trying this pre-cure trick, but then decided to check the level of my platform. Contrary to the calibration process being happy (many times) I found that my platform was not level with the rest of the printer. I ended up manually leveling my platform and now prints are sticking well for me with no help. So others having issues my throw a level on their platform, tank, and frame to make sure things are as level as they should be.

RE: First layer doesn't stick.

When using normal resin I've found that using Monocure 3D Platebond makes the first layer stick reliably to the print bed, rather than the FEP. See https://monocure3d.com.au/product-category/platebond/?v=322b26af01d5. Its a urethane, like Monocure 3D Tuff. Mixing urethane with a non-urethane normal resin works fine. Platebond comes in a little bottle with a roller ball encapsulated in the neck of the bottle. Roll the ball over the surface of the print bed to make a sticky layer for the resin.

When using Monocure 3D Tuff resin I hammer the part off the print bed with tack hammer and putty knife, so don't need to use Platebond; See https://monocure3d.com.au/about-our-resin/?v=322b26af01d5

RE: First layer doesn't stick.

@ejberg

Great thinking, this has worked for me and resolved my frustrating first attempts printing the examples.  I had scrubbed, cleaned, re-callibrated with no success, but a very thin smear and a 1 minute cure did the trick. 👍 👍 👍