FEP over PDMS = orange VAT solution

Successful prints based on Model construction, supports, material selection & printer settings.
kai
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FEP over PDMS = orange VAT solution

Post#1 » Mon Aug 14, 2017 11:17 pm

Hi all,
I have been applying FEP film over a freshly PDMS coated orange VAT with great success. I am printing over 30+ hours and the PDMS is clear. As the resin is not in contact with the PDMS no ghosting occurs.

Silicone adhesive FEP film works fine for me. If there are any bubbles you can just lift the FEP up and re-apply it. Also if for some reason the FEP film gets destroyed or looses its properties you can get it off easily and apply a new one without recoating the PDMS.

In my case I did not have to modify the MSM as the distance from the printing surface to projector is the same. I modified some material properties as mentioned in other threads as the FEP is different from normal PDMS.

BTW, I am using the B9C in the 30 microns setting for jewelry.


Kai

Bexley
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Re: FEP over PDMS = orange VAT solution

Post#2 » Mon Aug 14, 2017 11:21 pm

Extremely interesting. Where do you get your film from? (Plus a link, if you have it. ;))

Bexley
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Re: FEP over PDMS = orange VAT solution

Post#3 » Mon Aug 14, 2017 11:23 pm

Though, now that I think about it, I seem to recall FEP isn't a good solution for large models. Am I recalling that correctly?

kai
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Re: FEP over PDMS = orange VAT solution

Post#4 » Mon Aug 14, 2017 11:29 pm

Yes, I think I have read it as well. I only use it for rings and coin sized objects.

I bought it here:
http://catalog.cshyde.com/item/3d-print ... -5s-3d-6x6

I just use enough FEP so that it covers the 30micron area, but from front to back (otherwise the wiper makes problems).I think with one sheet you can get like 2-3 30micron "lanes".

Bexley
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Re: FEP over PDMS = orange VAT solution

Post#5 » Mon Aug 14, 2017 11:35 pm

Hm. Might be worth it to pick up a third vat and give it a FEP sheet for the smaller stuff I print. Thanks!

jep524
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Re: FEP over PDMS = orange VAT solution

Post#6 » Thu Sep 21, 2017 10:06 am

Firstly, thank you for sharing this! I was really interested in trying it out and I finally did today but got major sticking on the first layer of a calibration print. I had to actually unplug the machine and restart to pull the table off. I was wondering what you changed your material settings to and for what resin? I'm using Emerald and my build table is sanded down as well - I've read that helps. I am really hoping I can get this working but not sure what settings to tweak to improve it, any suggestions?

kai
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Re: FEP over PDMS = orange VAT solution

Post#7 » Thu Sep 21, 2017 10:49 am

Hi,
I duplicated the Emerald settings in the B9C software and set the attach multiplier to "2" and attach layers to "1". These are the only two settings you have to play with. You can test with different numbers and pause after a couple of layers to check if the print sticks. The calibration prints are a bit of a struggle with the FEP because they cover the complete build area. I am currently printing everything with the FEP on top the PDMS and the prints come out great. No more ghosting.

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akgold
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Re: FEP over PDMS = orange VAT solution

Post#8 » Thu Sep 21, 2017 1:10 pm

Don't use any PDMS and apply the FEP directly to the glass
See how that works out for you.
I'm so far behind I think I'm First !!

Aaron RMW
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Re: FEP over PDMS = orange VAT solution

Post#9 » Thu Sep 21, 2017 1:42 pm

As soon as someone tries it, please let me know if FEP alone is a good coating, I'm dying to find something that is less high maintenance than the PDMS coating system. when an average print runs for 10-12 hours i'm getting 2 MAYBE 3 good prints before clouding becomes an issue. it's driving me batty. I've also got a vat that the PDMS keeps pulling away from the walls and the window, just not sticking where it should and apparently shrinking away. I don't know what could be causing that and just want to be done with PDMS forever.

kai
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Re: FEP over PDMS = orange VAT solution

Post#10 » Thu Sep 21, 2017 2:57 pm

It is for the orange VAT with plexiglass. Pulling of the FEP film from the plexiglass directly might cause some problems (I have read it in the forum before).
But there were actually various reasons for me to apply the FEP over the PDMS: a) solution for orange VAT (see top), b) easy to get off and to realign if necessary. This cannot be done with a glass surface as well. I have had problems with bubbles in the past on glass, but it just might be my clumsiness, c) no modification of the MSM as distance to projector is the same as with PDMS only and d) no modification of the "Home" parameter (build table is at almost same height). Given all that one can also switch easily between FEP and PDMS only.

My 2 cents,
Kai

johnh
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Re: FEP over PDMS = orange VAT solution

Post#11 » Fri Sep 22, 2017 9:16 am

Kai,
How many hours of printing have you printed without replacing the FEP or pdms?

kai
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Re: FEP over PDMS = orange VAT solution

Post#12 » Fri Sep 22, 2017 2:00 pm

Around 60+ hours on the same PDMS. I changed the FEP once because the first time I applied it I made a couple of mistakes. Replacing the FEP is fast, it peels of easily. You just need to remove the resin, so it cannot get in between FEP and PDMS.
The PDMS itself looks like new. I think PDMS is normally used for solar panels, it does not react with UV light. It is the combination of UV and resin which causes the ghosting.

kreffell
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Re: FEP over PDMS = orange VAT solution

Post#13 » Sun Sep 24, 2017 7:23 am

I have not used this film yet but might be worth a try:

http://www.muve3d.net/press/product/fep ... r-coating/

andreas
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Re: FEP over PDMS = orange VAT solution

Post#14 » Sun Sep 24, 2017 7:40 am

kai can you show some photos of the prints??

kreffel this fep has no adhesive..you need to find at least 0.5mm thick with adhesive back

kreffell
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Re: FEP over PDMS = orange VAT solution

Post#15 » Sun Sep 24, 2017 7:59 am

Strange the installation document states:

While holding the edge you just placed on the glass, slowly peel back about half of the backing from the tape while making sure not to wrinkle it. This can be difficult and practice will make it easier, just be patient and go slow.

andreas
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Re: FEP over PDMS = orange VAT solution

Post#16 » Sun Sep 24, 2017 8:05 am

i have tried them my self months ago..no good ..too thin with no adhesion force..

dont forget the side by side movement of the vat..
you need thick fep that can take a beating..
the thicker the better...

search in the forum my post for fep testing..maybe you find it usefull..
Last edited by andreas on Sun Sep 24, 2017 8:13 am, edited 1 time in total.

kreffell
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Re: FEP over PDMS = orange VAT solution

Post#17 » Sun Sep 24, 2017 8:10 am

ah, thanks for clarifying that.

kai
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Re: FEP over PDMS = orange VAT solution

Post#18 » Sun Sep 24, 2017 1:13 pm

Here are a couple of photos. The larger object has a width of 1.8cm, the smaller of 1.6cm. We use the 3d prints to make silicone molds. This print is just a design approval print. The level of detail with the FEP is the same as with a fresh clear PDMS without FEP. Sometimes we have prints with 0.2mm details or a bit less and they come out fine. With a clouded PDMS it is impossible to get the fine details right. It was always painful to move the objects around to find a space without clouding. Now I can print right in the middle without fear of clouding the space.


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panastation
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Re: FEP over PDMS = orange VAT solution

Post#19 » Sun Sep 24, 2017 7:09 pm

thanks for sharing. question is your printer low on lamp hours or above 600hrs. So u apply fep over pdms hmm..
how thick is the film itself..

Aaron RMW
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Re: FEP over PDMS = orange VAT solution

Post#20 » Mon Sep 25, 2017 7:59 am

will this only work in the orange vats or could it be used in the aluminum vats as well? is there something special about having the plexiglass window (more flex maybe) that is necessary for the FEP over PDMS?

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