FEP Vat failure


#23

Before you use it, confirm the type of Rain-X. The Rain-X for glass has some pretty strong organic solvents, while the Rain-X for plastics does not. Normal Rain-X works fine on PDMS, but does not seem to last. You may end up having to recoat between prints.


#24

I think people use regular rain-X, not the one for plastics. I would have to confirm that… have you used it?

As for the use of it… i was talking about using the rain-X on the FEP vat, not the PDMS one.

I guess it makes sense that you need to recoat it often since the process of peeling the part from the FEP will most likely pull off the rain-X from it.


#25

FEP is a bit stickier than PDMS and is more sensitive to debris in the vat. It requires thicker support and better placement. That was source of the issue for some of users having problem. PDMS for all its faults , is very tolerant of printing practices. (We have hold this opinion from the very beginning of the discussion)

We made FEP vat for production users as target group. Once FEP vat dials in, it just goes on print and print for kgs of resins and great finishes due to its flat surface. Leveling never changes even if you put on a new film (assuming it is the same thickness and tension-ed properly)

It is not meant to “use cheaper resins” because not only our resins are quite a low cost if you considered its high polymer content., A lot cheaper LCD resins cannot handle the combination laser and peel force and would create all sorts of weird results. Hence FEP is not making a guarantee for 3rd party resins. It is ideal to be used with resins with more interesting properties that could also be corrosive (*if the resins are well made and tested for laser).


#26

printing tips if you are still having issue:

  1. Try to level to 10.8-10.9mm such that there is not too much pressure on the vat while the print still get good adhesion

  2. increase pm reset distance from 40 to 60 and in some case, 80

  3. make sure the fep vat is free of debris,

  4. use thicker support


#27

Hi,
I’ve go the same issue.
I use quite thick supports and thick support base ( about 1,5mm) and its fails in bigger objects.

This was the best result i’ve got using FEP vat


#28

Yeah - Ive pretty much decided that the FEP vat is fine for stuff around a couple of inches in size, anything more than that its a total failure as a system. Ill keep it around for smaller work and just use PDMS with the leveling printbed for everything else. Shame really.


#29

Would it be possible for @Peopoly to show some examples of big objects printed with the new FEP VAT?

I´m almost giving up either, made a print ok with the ring test, but already got a failure with a 80mm tall object.
I´m giving it another try (and spending more resin), should be posting the results today or tomorrow.

Honestly, if this is a design fault/problem, I think we should have the right to know.


#30

Update: riped off printed parts, layers separation, simply terrible. @peopoly, what’s going on?!

IMG_20180907_172810515_HDR|375x500


#31

@peopoly, after the last failure, decided to clean the FEP VAT and switch resins, then I saw the FEP has some marks/scratches and what appears to be a torn/cut. So, got my extra FEP, opened it and found that it came with a part that is ripped off. Even then, decided to switch the FEP film, since the one already in the VAT looked worse. When I tryied to loosen the screws, four of them simply spammed/stripped. Now, I have a FEP VAT which I can’t replace the FEP film for good. I’d really like to hear something about it from @peopoly, because it’s gettting impossible to work with my Moai right now.


#32

Had the same Problem with one of my screws.


#33

Hi Kevin, did you manage to remove the screw?


#34

Try gluing the allen key to the screw and then twist slowly.


#35

Thanks Leonardo, I Will.


#36

I couldn’t glue anything, because there was not enough hexagon left :smile:

You can also try to drill to holes near the existing one, to form som sort of line and than try with a flathead.

But i drilled the screw out with a little drill and inserted a new screw( i have a ton of them). @peopoly some extra screws would be nice i think.


#37

Thanks Kevin, I´ll try that too after trying to glue it, but I think my screws are really in bad shape.
One thing I noticed, these screws are just too soft and fragile. The new plataform too, really soft screws.


#38

Hmm… i guess im gonna start looking into new screws then, just to be on the safe side when the time comes to change the fep


#39

Drilling them out always works, but should also be the last method, because its pretty easy to destroy the screw thread( is that the correct word? :thinking:)


#40

with a rotary tool cut a slot into the screw and use a large flat screw driver to unscrew it.


#41

Thanks Matt, I have a dremel and some rotatory discs, going to try with them. By the way, do you know which size are those screws? I´m thinking about switching all of them (and the ones from the new adjustable base plate) for stronger screws.


#42

I haven’t checked but should be easy to find out, I believe the screws are actually good quality, though. I have a feeling the problem is with the threading in the aluminum.