Wiper System?

[CSM]

Hello,

I am in the process of gathering parts for a top down dlp sla printer, however I have a question regarding a wiper system for the bottom up style printers. What exactly is a wiper system? Would it replace PDMS or Teflon?

Thanks,

Cameron

[PacManFan]

I'm not sure what a wiper system would do in the context of a bottom-up system. In a top down system, they are used to wipe at thin layer of resin to ensure consistent layer thickness prior to layer exposure.

[EdgE]

The ProJet® 1500 from 3D-systems also uses a wiper for their bottom-up system.
After each exposure, a small 'windscreen' wiper removes the resin & the vat will be filled again by a new thin resin layer by an (expensive) cartridge.
(I'm not sure if all the wiped resin is waste or not.)

Szzer also created a wiper system on top of his PDMS vat.
And activate his every 10 exposures. It seams to work, having a longer vat life.

[android78]

Wow, you're right!
I took a look at the following after I read you post:
https://www.youtube.com/watch?v=oG2kV_qBJ8o

It seems like it spreads just enough resin for the layer on the glass and then, after curing the layer, it then wipes off the glass. I think this could help avoid partial cured resin from around the edge of the part from building up and creating artefacts. I would imagine that it would have to had the resin go through a filter and be re-used though, or else it would waste a heck of a lot.

[Finhead]

I believe the wiper system on machines like the ProJet 1500 serves the same function as the B9 Creator wiper. The B9 does the wipe and peel at the same time but I think it has the same end result for exposing the VAT material to air.

[android78]

What is the benefit of exposing the resin to air? Does it help speed the curing?

[EdgE]

It's not the resin which you want to expose to air, it's the air which is temporary exposed to the PDMS.
So the PDMS layer will be refreshed.
That's why I believe in this method.
Hopefully next week, I start to build this myself also.