Acrylic Flex Vat

Various topics related to Vat design, construction and coatings.
Glacian22
Posts: 63
Joined: Wed Feb 19, 2014 4:23 am

Acrylic Flex Vat

Postby Glacian22 » Tue Aug 05, 2014 6:23 pm

So after seeing Finhead's flex bottom vat, I decided to try my hand at making my own. :D
Image
Image

The rectangle parts are laser cut, while the vat walls were saw cut and routed to make sure they'd bond well. The teflon is clamped between the top two pieces with a ring of silicone as sealant, and then that whole bit is set on the tensioning frame, and will be held down with some screw clamps.

I was hoping that I'd just be able to apply the silicone, let it dry, and then clamp the FEP, but that didn't give a water tight seal, unexpectedly. Fortunately, applying the silicone and then immediately clamping it all together seems to have done just fine, it'll just be obnoxious to have to let the new silicone dry when I eventually have to change out the FEP. For the lower tensioning frame, I just used a dremel to smooth the edges of the acrylic so the FEP shouldn't possibly be damaged while tensioning it.

Time to go test it out, I'll post the results! :mrgreen:

seasicksinbad
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Re: Acrylic Flex Vat

Postby seasicksinbad » Fri Aug 08, 2014 12:35 pm

Very nice!
Keep the pictures coming.
Thanks for sharing.
Did you reinforce the FEP with thin plastic? or is it just a FEP membrane.
Time flies like an arrow, fruit flies like a banana.

Glacian22
Posts: 63
Joined: Wed Feb 19, 2014 4:23 am

Re: Acrylic Flex Vat

Postby Glacian22 » Fri Aug 08, 2014 5:31 pm

I bonded the FEP to a sheet of .005" polycarbonate using some transfer adhesive. The vat works, but unfortunately the acrylic started to crack under the stress, so I'm rebuilding the whole thing out of 1/4" polycarbonate which should be *much* sturdier. ^_^

seasicksinbad
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Re: Acrylic Flex Vat

Postby seasicksinbad » Fri Aug 08, 2014 10:54 pm

Wow!! Wouldn't 1/4" polycarbonate defeat the purpose? I've worked with lexan as thin as 1/32" under lots of stress and it has never cracked, it bends easily but never cracks. I would check my material sources first and make sure it really is polycarbonate instead of plexiglass or acrylic.
Time flies like an arrow, fruit flies like a banana.

Glacian22
Posts: 63
Joined: Wed Feb 19, 2014 4:23 am

Re: Acrylic Flex Vat

Postby Glacian22 » Sat Aug 09, 2014 3:58 am

Oops, I should clarify: I'm rebuilding the walls/structural pieces of the vat out of 1/4 inch polycarbonate, the nonstick coating is still backed with just .005 inch PC. So the new all PC vat just finished drying after being solvent welded together, and it's actually very sturdy, and it really is polycarbonate. The lower section that's just a hollow rectangle is still a bit flexible, but still serves its purpose since the top of the vat is totally rigid. I'll give it a test run tomorrow and report back. :)

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PacManFan
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Re: Acrylic Flex Vat

Postby PacManFan » Sat Aug 09, 2014 11:04 am

Excellent! I can't wait to hear how it performs.

adambx
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Joined: Wed Apr 09, 2014 6:33 am

Re: Acrylic Flex Vat

Postby adambx » Sun Aug 10, 2014 7:25 am

anz reports on the lifetime of an FEP VAT?

Has anyone tried PFA Yet? It's supposed to be more transparent than FEP and have better anti-stick properties
http://www.norton-films.com/pfa-hp-films.aspx

Glacian22
Posts: 63
Joined: Wed Feb 19, 2014 4:23 am

Re: Acrylic Flex Vat

Postby Glacian22 » Sun Aug 10, 2014 2:05 pm

I haven't tried PFA, but I just ordered some from CS Hyde to test it out. Thanks for the heads up! :D

dangre
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Location: SW Michigan

Re: Acrylic Flex Vat

Postby dangre » Thu Sep 04, 2014 10:34 pm

I've tried my version of a FEP vat and after much tweaking, it is working. I used some acrylic to clamp the FEP but it appears the SubG+ makes any stress riser in the acrylic to magnify. I am using .005" FEP with no backer and had significant 'ballooning' of the FEP with my solid build plate. Drilling relief holes helped but I could still only build on the edges where the FEP/build plate were closer. I ended up making a small (1" sq) subplate which works fine. I will be making a perforated build plate which should eliminate that issue. Has anyone tried thicker FEP or FPA? The FEP noticeably softens visually on large areas of light exposure.
Dan - mUVe 1 DLP