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Re: Basic information

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  • richkang78
    Hi Bito, You should pick the brains of the members involved in the lcd panel based printer thread, as they are trying to do what you are describing. The
    Message 1 of 8 , Nov 7, 2012
      Hi Bito,

      You should pick the brains of the members involved in the "lcd panel based printer" thread, as they are trying to do what you are describing.

      The height of a 1080p image is made up of 1080 pixels. If you project that to a 300mm height, you simply divide 300mm/1080=.278mm. That is the "height" of one pixel, and your resolution in the xy dimension.

      The vat that I have been describing has a pdms layer, which is in a sense "non-stick" but that does not solve the the issue of suction that is created when trying to separate two adjacent smooth surfaces immersed in viscous resin. This is the real "vat-sticking" issue people here are describing, not one based on adhesion.

      Rich
      --- In diy_3d_printing_and_fabrication@yahoogroups.com, "bitoli00" <bitoli00@...> wrote:
      >
      > Sorry for double post.
      >
      > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "bitoli00" <bitoli00@> wrote:
      > >
      > > Can you tell me how you calculated the x/y resolution?
      > >
      > > I thought about using a strong UV lamp together with a LCD display. The idea is, to absorb some of the uv light by making the areas that shouldn't cure dark and those who should cure white or something like this. This idea is similar to an digital overhead projector i already build using a fresnel lens, a bright lamp and a full hd display of a tft.
      > >
      > > Im pretty sure there are many ideas around a coating on the bottom of the vat to avoid the print sticking on the bottom, or?
      > >
      > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "richkang78" <richkang78@> wrote:
      > > >
      > > > First off, most projectors have a 16:9 aspect ratio, so it you won't be getting a square build platform. If you scaled a 1080p projection so that you had a 533mm x300mm, you would have .27mm resolution on the xy dimension. The z resolution is adjustable by you to an extent based on the type of resin mix you have projector brightness. If that seems reasonable to you, I would get the a 1080p dlp projector with the highest lumen rating available. If money is no object, I am sure there are much higher resolution projectors available.
      > > >
      > > > Depending on the throw of the projector image, you can adjust the projector location and focus to print smaller and at higher res.
      > > >
      > > > Please read up on vat sticking/vacuum. Vat sliding and tilting are methods to get the part off of the vat surface. This is directly related to the amount of surface area in contact vat-face to buildplate-face. The greater the surface area, the more difficult it is to quickly separate the build platform and vat. It is not unreasonable to have sliding vat your size, but it would be big. You say that you want to print thinner parts at low resolution, which is better, as thinner printed areas separate more easily from a vat than a larger area (ie. long rectangle vs. circle with same area).
      > > >
      > > > There are many other things to consider when making such a large print area.
      > > >
      > > > If I were going for a large build area as you describe, I would probably opt for an inverted cartesian-coordinate laser diode based system, similar to what someone else on the group has built. It may take longer to make prints, but would not be bad if you have thin-walled models. Also, you can gain some resolution and save cost in comparison to a projector.
      > > >
      > > > Rich
      > > >
      > > >
      > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "bitoli00" <bitoli00@> wrote:
      > > > >
      > > > > Hi Rich,
      > > > >
      > > > > thanks for the explanation. My aim is a 300x300x300mm print size cause im printing allot of bigger (thin) things like combustion chambers and compressor/turbine stages of jet engines. I thought about a printer that can print those big parts with less resolution and smaller part with higher resolution, only changing the focus of the projector. But i have no idea which kind of projector to use for such a big build volume. I dont understand how the vat can limit my build size until i can build the vat as big as i want. Or am i wrong?
      > > > >
      > > > > Bito
      > > > >
      > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "richkang78" <richkang78@> wrote:
      > > > > >
      > > > > > Hi Bito,
      > > > > >
      > > > > > There is a inverse relationship between the size of prints (x&y dimension) and the resolution of the print. The brightness in lumens of your DLP light source ultimately determines the practical limits of your overall print size as the larger you project your image, the longer it will take to cure a single layer. Another important limiting factor is the vat size. A better place to start is to know what size and resolution you desire and build a system that fits those requirements. So what are your print size goals?
      > > > > > Rich
      > > > > >
      > > > > >
      > > > > >
      > > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "bitoli00" <bitoli00@> wrote:
      > > > > > >
      > > > > > > Hi all,
      > > > > > >
      > > > > > > im owner of an Ultimaker 3D printer and im searching for higher resolution solutions. This way i found this Yahoo! group. Im very interested in the basics of dlp printing.
      > > > > > >
      > > > > > > My first questions are:
      > > > > > >
      > > > > > > 1. What is the max. size of prints?
      > > > > > > 2. What limits this max. size?
      > > > > > >
      > > > > > > I would be glad to get some links to previous topics where these questions already been answered or where i can find the basics about dlp printing.
      > > > > > >
      > > > > > >
      > > > > > > Kind regards
      > > > > > > Bito
      > > > > > >
      > > > > >
      > > > >
      > > >
      > >
      >
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