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Bed Size for dlp based printers

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  • Rafael Vargas
    Hello, Ive been looking around throughout the many posts and responses here in this amazing yahoo group. I have noticed that there are many DIY resin printers
    Message 1 of 10 , Apr 3 6:44 AM
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      Hello,

      Ive been looking around throughout the many posts and responses here in this amazing yahoo group. I have noticed that there are many DIY resin printers that  are  focused with a lens, with the specific purpose having a very minimal focus area (in the millimiter scale). And I have seen others like this amazing project from Sci_Arc previously posted http://vimeo.com/49888105 , that I can estimate it has approx 1 ft x 1 ft printable surface bed area. Now, here is where I want to come in. I am very interested in researching for the larger size, less resolution approach for industrial design purposes. But, can't seem to find where to start as a knowledge base for the bed size. I certainly know that the less focus size it has the more resolution the print will have and that lenses can help to minimize the distance between the projector and the bed. But are there any standard relations of for example (projector resolution, lumens, distance, and size)?. I can certainly start researching on this by building my prototype but wanted to know if anybody had any previous knowledge on it. I would appreciate it very much. That way I can know if one projector is better than another for larger bed size, know if its possible to acquire a 2ft printable bed size area with good results  etc. and start posting my results here for everybody's knowledge. Sorry if i have missed a post regarding this topic I really tried reading all related posts and using the search bar but couldn't find any specific answers. 
    • jmelson2
      ... I am very ... The problem is the exposure time per layer.many of the guys are working with object sizes around 100 mm, and layer cycle times under 10
      Message 2 of 10 , Apr 3 3:53 PM
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        --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas <vargas.correa.rafael@...> wrote:
        >
        I am very
        > interested in researching for the larger size, less resolution approach for
        > industrial design purposes.know if its possible
        > to acquire a 2ft printable bed size area with good results etc.
        The problem is the exposure time per layer.many of the guys
        are working with object sizes around 100 mm, and layer cycle
        times under 10 seconds. Some of them now have exposures of just
        a FEW seconds with the latest resins from SpotA. That is a huge improvement over a few years ago.

        When scaling exposure time, it goes as the square of linear dimension.
        So, if you double the linear dimension, the exposure required is 4 X as long. Now, to scale a 2 second exposure at 100 mm to a linear dimension of 2 feet, that comes to ~600mm, or 6X the dimension.
        So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
        bad as I thought! There may be object-to-bed sticking problems
        with an object this size, you might have to go with the top-down
        build instead of the glass bottomed vat scheme that is used by a
        lot of our group. (The sticking problem may not exist, but there could be problems casting the sylguard to the vat bottom, it might shrink and peel or something.) Also, these objects tend to shrink, and a resilient base needs to be built on the build platform to accommodate the shrinkage, or the model breaks free from the platform as it is being built. I assume this problem has to get worse with larger objects. If it just barely works at 100 mm, it is going to be a real bear at 600 mm.

        These are just some concerns that occur to me, a reader of this group
        with no experience (so far) in the field.

        Jon
      • pzamov
        @Group ... I have NOT noticed the normal progression of the exposure times when my printer was printing with the larger platform. So it depends on resin /
        Message 3 of 10 , Apr 6 11:44 PM
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          @Group
          >So, if you double the linear dimension, the exposure required is 4 X >as long.

          I have NOT noticed the normal progression of the exposure times when my printer was printing with the larger platform. So it depends on resin / photo-initiator mix and projector.

          The Exposures I have been using from the beginning is about 2-3 seconds exposure.

          > So, 6 x 6 = 36, and the exposure would be 72 seconds.
          I burn-in the base layer for 30sec. That would be 180 sec for a large area and even that is not bad at all.

          > There may be object-to-bed sticking problems
          > with an object this size, you might have to go with the top-down
          > build instead

          I would second that. It might be easier to just do a Top-Down with a wiper and bare the cost of large amount of resin considering the ease of construction. Not to mention the vacuum forces would not be an issue.

          > If it just barely works at 100 mm
          Correction! It works rather well and it can go larger, but we do not have grants to be able to freely research that.
          It's proven it works well up to 192mm X 108mm @100 micron ( maybe even larger ).

          Cheers! :-)
          Peter





          --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2" <elson@...> wrote:
          >
          >
          >
          > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas <vargas.correa.rafael@> wrote:
          > >
          > I am very
          > > interested in researching for the larger size, less resolution approach for
          > > industrial design purposes.know if its possible
          > > to acquire a 2ft printable bed size area with good results etc.
          > The problem is the exposure time per layer.many of the guys
          > are working with object sizes around 100 mm, and layer cycle
          > times under 10 seconds. Some of them now have exposures of just
          > a FEW seconds with the latest resins from SpotA. That is a huge improvement over a few years ago.
          >
          > When scaling exposure time, it goes as the square of linear dimension.
          > So, if you double the linear dimension, the exposure required is 4 X as long. Now, to scale a 2 second exposure at 100 mm to a linear dimension of 2 feet, that comes to ~600mm, or 6X the dimension.
          > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
          > bad as I thought! There may be object-to-bed sticking problems
          > with an object this size, you might have to go with the top-down
          > build instead of the glass bottomed vat scheme that is used by a
          > lot of our group. (The sticking problem may not exist, but there could be problems casting the sylguard to the vat bottom, it might shrink and peel or something.) Also, these objects tend to shrink, and a resilient base needs to be built on the build platform to accommodate the shrinkage, or the model breaks free from the platform as it is being built. I assume this problem has to get worse with larger objects. If it just barely works at 100 mm, it is going to be a real bear at 600 mm.
          >
          > These are just some concerns that occur to me, a reader of this group
          > with no experience (so far) in the field.
          >
          > Jon
          >
        • Rafael Vargas
          Thanks guys for the info! I think this month I will start some experiments dealing with all this stuff. Peter, how big have you gone experimenting? And, what
          Message 4 of 10 , Apr 8 1:43 AM
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            Thanks guys for the info!

            I think this month I will start some experiments dealing with all this stuff.

            Peter, how big have you gone experimenting?

            And, what projector would you guys recommend? Should it be the highest resolution possible? (to use large areas).
            What resin should be more suitable? also.

            Right now I have acces to a fabrication laboratory in which I can start prototyping for samples. 
            Any help would be great!

            Best.


            On Sun, Apr 7, 2013 at 8:44 AM, pzamov <pzamov@...> wrote:
             

            @Group


            >So, if you double the linear dimension, the exposure required is 4 X >as long.

            I have NOT noticed the normal progression of the exposure times when my printer was printing with the larger platform. So it depends on resin / photo-initiator mix and projector.

            The Exposures I have been using from the beginning is about 2-3 seconds exposure.


            > So, 6 x 6 = 36, and the exposure would be 72 seconds.
            I burn-in the base layer for 30sec. That would be 180 sec for a large area and even that is not bad at all.


            > There may be object-to-bed sticking problems
            > with an object this size, you might have to go with the top-down
            > build instead

            I would second that. It might be easier to just do a Top-Down with a wiper and bare the cost of large amount of resin considering the ease of construction. Not to mention the vacuum forces would not be an issue.


            > If it just barely works at 100 mm
            Correction! It works rather well and it can go larger, but we do not have grants to be able to freely research that.
            It's proven it works well up to 192mm X 108mm @100 micron ( maybe even larger ).

            Cheers! :-)
            Peter

            --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2" <elson@...> wrote:

            >
            >
            >
            > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas <vargas.correa.rafael@> wrote:
            > >
            > I am very
            > > interested in researching for the larger size, less resolution approach for
            > > industrial design purposes.know if its possible
            > > to acquire a 2ft printable bed size area with good results etc.
            > The problem is the exposure time per layer.many of the guys
            > are working with object sizes around 100 mm, and layer cycle
            > times under 10 seconds. Some of them now have exposures of just
            > a FEW seconds with the latest resins from SpotA. That is a huge improvement over a few years ago.
            >
            > When scaling exposure time, it goes as the square of linear dimension.
            > So, if you double the linear dimension, the exposure required is 4 X as long. Now, to scale a 2 second exposure at 100 mm to a linear dimension of 2 feet, that comes to ~600mm, or 6X the dimension.
            > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
            > bad as I thought! There may be object-to-bed sticking problems
            > with an object this size, you might have to go with the top-down
            > build instead of the glass bottomed vat scheme that is used by a
            > lot of our group. (The sticking problem may not exist, but there could be problems casting the sylguard to the vat bottom, it might shrink and peel or something.) Also, these objects tend to shrink, and a resilient base needs to be built on the build platform to accommodate the shrinkage, or the model breaks free from the platform as it is being built. I assume this problem has to get worse with larger objects. If it just barely works at 100 mm, it is going to be a real bear at 600 mm.
            >
            > These are just some concerns that occur to me, a reader of this group
            > with no experience (so far) in the field.
            >
            > Jon
            >


          • pzamov
            Hi Rafael, I tired a 1024x768 and it was working well enough that I thought I could go larger, but had no need. My target was small scale and high resolution.
            Message 5 of 10 , Apr 8 12:05 PM
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              Hi Rafael,
              I tired a 1024x768 and it was working well enough that I thought I could go larger, but had no need. My target was small scale and high resolution. E-tech has a 1920x1200 machine and they have no problems printing @100 micron resolution.

              I ran my tests in the very beginning with Dymax 9663. Now I use resin from Fernando.

              Cheers!
              Peter


              --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas <vargas.correa.rafael@...> wrote:
              >
              > Thanks guys for the info!
              >
              > I think this month I will start some experiments dealing with all this
              > stuff.
              >
              > Peter, how big have you gone experimenting?
              >
              > And, what projector would you guys recommend? Should it be the highest
              > resolution possible? (to use large areas).
              > What resin should be more suitable? also.
              >
              > Right now I have acces to a fabrication laboratory in which I can
              > start prototyping for samples.
              > Any help would be great!
              >
              > Best.
              >
              >
              > On Sun, Apr 7, 2013 at 8:44 AM, pzamov <pzamov@...> wrote:
              >
              > > **
              > >
              > >
              > > @Group
              > >
              > > >So, if you double the linear dimension, the exposure required is 4 X >as
              > > long.
              > >
              > > I have NOT noticed the normal progression of the exposure times when my
              > > printer was printing with the larger platform. So it depends on resin /
              > > photo-initiator mix and projector.
              > >
              > > The Exposures I have been using from the beginning is about 2-3 seconds
              > > exposure.
              > >
              > >
              > > > So, 6 x 6 = 36, and the exposure would be 72 seconds.
              > > I burn-in the base layer for 30sec. That would be 180 sec for a large area
              > > and even that is not bad at all.
              > >
              > >
              > > > There may be object-to-bed sticking problems
              > > > with an object this size, you might have to go with the top-down
              > > > build instead
              > >
              > > I would second that. It might be easier to just do a Top-Down with a wiper
              > > and bare the cost of large amount of resin considering the ease of
              > > construction. Not to mention the vacuum forces would not be an issue.
              > >
              > >
              > > > If it just barely works at 100 mm
              > > Correction! It works rather well and it can go larger, but we do not have
              > > grants to be able to freely research that.
              > > It's proven it works well up to 192mm X 108mm @100 micron ( maybe even
              > > larger ).
              > >
              > > Cheers! :-)
              > > Peter
              > >
              > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2" <elson@>
              > > wrote:
              > >
              > > >
              > > >
              > > >
              > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas
              > > <vargas.correa.rafael@> wrote:
              > > > >
              > > > I am very
              > > > > interested in researching for the larger size, less resolution
              > > approach for
              > > > > industrial design purposes.know if its possible
              > > > > to acquire a 2ft printable bed size area with good results etc.
              > > > The problem is the exposure time per layer.many of the guys
              > > > are working with object sizes around 100 mm, and layer cycle
              > > > times under 10 seconds. Some of them now have exposures of just
              > > > a FEW seconds with the latest resins from SpotA. That is a huge
              > > improvement over a few years ago.
              > > >
              > > > When scaling exposure time, it goes as the square of linear dimension.
              > > > So, if you double the linear dimension, the exposure required is 4 X as
              > > long. Now, to scale a 2 second exposure at 100 mm to a linear dimension of
              > > 2 feet, that comes to ~600mm, or 6X the dimension.
              > > > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
              > > > bad as I thought! There may be object-to-bed sticking problems
              > > > with an object this size, you might have to go with the top-down
              > > > build instead of the glass bottomed vat scheme that is used by a
              > > > lot of our group. (The sticking problem may not exist, but there could
              > > be problems casting the sylguard to the vat bottom, it might shrink and
              > > peel or something.) Also, these objects tend to shrink, and a resilient
              > > base needs to be built on the build platform to accommodate the shrinkage,
              > > or the model breaks free from the platform as it is being built. I assume
              > > this problem has to get worse with larger objects. If it just barely works
              > > at 100 mm, it is going to be a real bear at 600 mm.
              > > >
              > > > These are just some concerns that occur to me, a reader of this group
              > > > with no experience (so far) in the field.
              > > >
              > > > Jon
              > > >
              > >
              > >
              > >
              >
            • travis serio
              ET also uses pixel shifting though, so their larger build platform areas will have a higher pixel density than 1920x1200 would typically produce.
              Message 6 of 10 , Apr 8 1:01 PM
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                ET also uses "pixel shifting" though, so their larger build platform areas will have a higher pixel density than 1920x1200 would typically produce. 


                On Mon, Apr 8, 2013 at 3:05 PM, pzamov <pzamov@...> wrote:
                 

                Hi Rafael,
                I tired a 1024x768 and it was working well enough that I thought I could go larger, but had no need. My target was small scale and high resolution. E-tech has a 1920x1200 machine and they have no problems printing @100 micron resolution.

                I ran my tests in the very beginning with Dymax 9663. Now I use resin from Fernando.

                Cheers!
                Peter

                --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas <vargas.correa.rafael@...> wrote:
                >
                > Thanks guys for the info!
                >
                > I think this month I will start some experiments dealing with all this
                > stuff.
                >
                > Peter, how big have you gone experimenting?
                >
                > And, what projector would you guys recommend? Should it be the highest
                > resolution possible? (to use large areas).
                > What resin should be more suitable? also.
                >
                > Right now I have acces to a fabrication laboratory in which I can
                > start prototyping for samples.
                > Any help would be great!
                >
                > Best.
                >
                >
                > On Sun, Apr 7, 2013 at 8:44 AM, pzamov <pzamov@...> wrote:
                >
                > > **
                > >
                > >
                > > @Group
                > >
                > > >So, if you double the linear dimension, the exposure required is 4 X >as
                > > long.
                > >
                > > I have NOT noticed the normal progression of the exposure times when my
                > > printer was printing with the larger platform. So it depends on resin /
                > > photo-initiator mix and projector.
                > >
                > > The Exposures I have been using from the beginning is about 2-3 seconds
                > > exposure.
                > >
                > >
                > > > So, 6 x 6 = 36, and the exposure would be 72 seconds.
                > > I burn-in the base layer for 30sec. That would be 180 sec for a large area
                > > and even that is not bad at all.
                > >
                > >
                > > > There may be object-to-bed sticking problems
                > > > with an object this size, you might have to go with the top-down
                > > > build instead
                > >
                > > I would second that. It might be easier to just do a Top-Down with a wiper
                > > and bare the cost of large amount of resin considering the ease of
                > > construction. Not to mention the vacuum forces would not be an issue.
                > >
                > >
                > > > If it just barely works at 100 mm
                > > Correction! It works rather well and it can go larger, but we do not have
                > > grants to be able to freely research that.
                > > It's proven it works well up to 192mm X 108mm @100 micron ( maybe even
                > > larger ).
                > >
                > > Cheers! :-)
                > > Peter
                > >
                > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2" <elson@>
                > > wrote:
                > >
                > > >
                > > >
                > > >
                > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas
                > > <vargas.correa.rafael@> wrote:
                > > > >
                > > > I am very
                > > > > interested in researching for the larger size, less resolution
                > > approach for
                > > > > industrial design purposes.know if its possible
                > > > > to acquire a 2ft printable bed size area with good results etc.
                > > > The problem is the exposure time per layer.many of the guys
                > > > are working with object sizes around 100 mm, and layer cycle
                > > > times under 10 seconds. Some of them now have exposures of just
                > > > a FEW seconds with the latest resins from SpotA. That is a huge
                > > improvement over a few years ago.
                > > >
                > > > When scaling exposure time, it goes as the square of linear dimension.
                > > > So, if you double the linear dimension, the exposure required is 4 X as
                > > long. Now, to scale a 2 second exposure at 100 mm to a linear dimension of
                > > 2 feet, that comes to ~600mm, or 6X the dimension.
                > > > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
                > > > bad as I thought! There may be object-to-bed sticking problems
                > > > with an object this size, you might have to go with the top-down
                > > > build instead of the glass bottomed vat scheme that is used by a
                > > > lot of our group. (The sticking problem may not exist, but there could
                > > be problems casting the sylguard to the vat bottom, it might shrink and
                > > peel or something.) Also, these objects tend to shrink, and a resilient
                > > base needs to be built on the build platform to accommodate the shrinkage,
                > > or the model breaks free from the platform as it is being built. I assume
                > > this problem has to get worse with larger objects. If it just barely works
                > > at 100 mm, it is going to be a real bear at 600 mm.
                > > >
                > > > These are just some concerns that occur to me, a reader of this group
                > > > with no experience (so far) in the field.
                > > >
                > > > Jon
                > > >
                > >
                > >
                > >
                >


              • pzamov
                Hi Trav, There are 2560x1600 projectors, but a bit pricey. with pixel shift you could in reality get a 25 micron resolution over 128mm x 80mm. Cheers! Peter
                Message 7 of 10 , Apr 10 1:36 PM
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                  Hi Trav,

                  There are 2560x1600 projectors, but a bit pricey.
                  with pixel shift you could in reality get a 25 micron resolution over 128mm x 80mm.

                  Cheers!
                  Peter

                  --- In diy_3d_printing_and_fabrication@yahoogroups.com, travis serio <travisserio@...> wrote:
                  >
                  > ET also uses "pixel shifting" though, so their larger build platform areas
                  > will have a higher pixel density than 1920x1200 would typically produce.
                  >
                  >
                  > On Mon, Apr 8, 2013 at 3:05 PM, pzamov <pzamov@...> wrote:
                  >
                  > > **
                  > >
                  > >
                  > > Hi Rafael,
                  > > I tired a 1024x768 and it was working well enough that I thought I could
                  > > go larger, but had no need. My target was small scale and high resolution.
                  > > E-tech has a 1920x1200 machine and they have no problems printing @100
                  > > micron resolution.
                  > >
                  > > I ran my tests in the very beginning with Dymax 9663. Now I use resin from
                  > > Fernando.
                  > >
                  > > Cheers!
                  > > Peter
                  > >
                  > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas
                  > > <vargas.correa.rafael@> wrote:
                  > > >
                  > > > Thanks guys for the info!
                  > > >
                  > > > I think this month I will start some experiments dealing with all this
                  > > > stuff.
                  > > >
                  > > > Peter, how big have you gone experimenting?
                  > > >
                  > > > And, what projector would you guys recommend? Should it be the highest
                  > > > resolution possible? (to use large areas).
                  > > > What resin should be more suitable? also.
                  > > >
                  > > > Right now I have acces to a fabrication laboratory in which I can
                  > > > start prototyping for samples.
                  > > > Any help would be great!
                  > > >
                  > > > Best.
                  > > >
                  > > >
                  > > > On Sun, Apr 7, 2013 at 8:44 AM, pzamov <pzamov@> wrote:
                  > > >
                  > > > > **
                  > > > >
                  > > > >
                  > > > > @Group
                  > > > >
                  > > > > >So, if you double the linear dimension, the exposure required is 4 X
                  > > >as
                  > > > > long.
                  > > > >
                  > > > > I have NOT noticed the normal progression of the exposure times when my
                  > > > > printer was printing with the larger platform. So it depends on resin /
                  > > > > photo-initiator mix and projector.
                  > > > >
                  > > > > The Exposures I have been using from the beginning is about 2-3 seconds
                  > > > > exposure.
                  > > > >
                  > > > >
                  > > > > > So, 6 x 6 = 36, and the exposure would be 72 seconds.
                  > > > > I burn-in the base layer for 30sec. That would be 180 sec for a large
                  > > area
                  > > > > and even that is not bad at all.
                  > > > >
                  > > > >
                  > > > > > There may be object-to-bed sticking problems
                  > > > > > with an object this size, you might have to go with the top-down
                  > > > > > build instead
                  > > > >
                  > > > > I would second that. It might be easier to just do a Top-Down with a
                  > > wiper
                  > > > > and bare the cost of large amount of resin considering the ease of
                  > > > > construction. Not to mention the vacuum forces would not be an issue.
                  > > > >
                  > > > >
                  > > > > > If it just barely works at 100 mm
                  > > > > Correction! It works rather well and it can go larger, but we do not
                  > > have
                  > > > > grants to be able to freely research that.
                  > > > > It's proven it works well up to 192mm X 108mm @100 micron ( maybe even
                  > > > > larger ).
                  > > > >
                  > > > > Cheers! :-)
                  > > > > Peter
                  > > > >
                  > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2"
                  > > <elson@>
                  > > > > wrote:
                  > > > >
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael
                  > > Vargas
                  > > > > <vargas.correa.rafael@> wrote:
                  > > > > > >
                  > > > > > I am very
                  > > > > > > interested in researching for the larger size, less resolution
                  > > > > approach for
                  > > > > > > industrial design purposes.know if its possible
                  > > > > > > to acquire a 2ft printable bed size area with good results etc.
                  > > > > > The problem is the exposure time per layer.many of the guys
                  > > > > > are working with object sizes around 100 mm, and layer cycle
                  > > > > > times under 10 seconds. Some of them now have exposures of just
                  > > > > > a FEW seconds with the latest resins from SpotA. That is a huge
                  > > > > improvement over a few years ago.
                  > > > > >
                  > > > > > When scaling exposure time, it goes as the square of linear
                  > > dimension.
                  > > > > > So, if you double the linear dimension, the exposure required is 4 X
                  > > as
                  > > > > long. Now, to scale a 2 second exposure at 100 mm to a linear
                  > > dimension of
                  > > > > 2 feet, that comes to ~600mm, or 6X the dimension.
                  > > > > > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
                  > > > > > bad as I thought! There may be object-to-bed sticking problems
                  > > > > > with an object this size, you might have to go with the top-down
                  > > > > > build instead of the glass bottomed vat scheme that is used by a
                  > > > > > lot of our group. (The sticking problem may not exist, but there
                  > > could
                  > > > > be problems casting the sylguard to the vat bottom, it might shrink and
                  > > > > peel or something.) Also, these objects tend to shrink, and a resilient
                  > > > > base needs to be built on the build platform to accommodate the
                  > > shrinkage,
                  > > > > or the model breaks free from the platform as it is being built. I
                  > > assume
                  > > > > this problem has to get worse with larger objects. If it just barely
                  > > works
                  > > > > at 100 mm, it is going to be a real bear at 600 mm.
                  > > > > >
                  > > > > > These are just some concerns that occur to me, a reader of this group
                  > > > > > with no experience (so far) in the field.
                  > > > > >
                  > > > > > Jon
                  > > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > >
                  > >
                  > >
                  > >
                  >
                • travis serio
                  And 4k is coming, too! :)
                  Message 8 of 10 , Apr 10 2:04 PM
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                    And 4k is coming, too!  :)




                    On Wed, Apr 10, 2013 at 4:36 PM, pzamov <pzamov@...> wrote:
                     

                    Hi Trav,

                    There are 2560x1600 projectors, but a bit pricey.
                    with pixel shift you could in reality get a 25 micron resolution over 128mm x 80mm.

                    Cheers!
                    Peter

                    --- In diy_3d_printing_and_fabrication@yahoogroups.com, travis serio <travisserio@...> wrote:
                    >
                    > ET also uses "pixel shifting" though, so their larger build platform areas
                    > will have a higher pixel density than 1920x1200 would typically produce.
                    >
                    >
                    > On Mon, Apr 8, 2013 at 3:05 PM, pzamov <pzamov@...> wrote:
                    >
                    > > **
                    > >
                    > >
                    > > Hi Rafael,
                    > > I tired a 1024x768 and it was working well enough that I thought I could
                    > > go larger, but had no need. My target was small scale and high resolution.
                    > > E-tech has a 1920x1200 machine and they have no problems printing @100
                    > > micron resolution.
                    > >
                    > > I ran my tests in the very beginning with Dymax 9663. Now I use resin from
                    > > Fernando.
                    > >
                    > > Cheers!
                    > > Peter
                    > >
                    > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael Vargas
                    > > <vargas.correa.rafael@> wrote:
                    > > >
                    > > > Thanks guys for the info!
                    > > >
                    > > > I think this month I will start some experiments dealing with all this
                    > > > stuff.
                    > > >
                    > > > Peter, how big have you gone experimenting?
                    > > >
                    > > > And, what projector would you guys recommend? Should it be the highest
                    > > > resolution possible? (to use large areas).
                    > > > What resin should be more suitable? also.
                    > > >
                    > > > Right now I have acces to a fabrication laboratory in which I can
                    > > > start prototyping for samples.
                    > > > Any help would be great!
                    > > >
                    > > > Best.
                    > > >
                    > > >
                    > > > On Sun, Apr 7, 2013 at 8:44 AM, pzamov <pzamov@> wrote:
                    > > >
                    > > > > **
                    > > > >
                    > > > >
                    > > > > @Group
                    > > > >
                    > > > > >So, if you double the linear dimension, the exposure required is 4 X
                    > > >as
                    > > > > long.
                    > > > >
                    > > > > I have NOT noticed the normal progression of the exposure times when my
                    > > > > printer was printing with the larger platform. So it depends on resin /
                    > > > > photo-initiator mix and projector.
                    > > > >
                    > > > > The Exposures I have been using from the beginning is about 2-3 seconds
                    > > > > exposure.
                    > > > >
                    > > > >
                    > > > > > So, 6 x 6 = 36, and the exposure would be 72 seconds.
                    > > > > I burn-in the base layer for 30sec. That would be 180 sec for a large
                    > > area
                    > > > > and even that is not bad at all.
                    > > > >
                    > > > >
                    > > > > > There may be object-to-bed sticking problems
                    > > > > > with an object this size, you might have to go with the top-down
                    > > > > > build instead
                    > > > >
                    > > > > I would second that. It might be easier to just do a Top-Down with a
                    > > wiper
                    > > > > and bare the cost of large amount of resin considering the ease of
                    > > > > construction. Not to mention the vacuum forces would not be an issue.
                    > > > >
                    > > > >
                    > > > > > If it just barely works at 100 mm
                    > > > > Correction! It works rather well and it can go larger, but we do not
                    > > have
                    > > > > grants to be able to freely research that.
                    > > > > It's proven it works well up to 192mm X 108mm @100 micron ( maybe even
                    > > > > larger ).
                    > > > >
                    > > > > Cheers! :-)
                    > > > > Peter
                    > > > >
                    > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "jmelson2"
                    > > <elson@>
                    > > > > wrote:
                    > > > >
                    > > > > >
                    > > > > >
                    > > > > >
                    > > > > > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Rafael
                    > > Vargas
                    > > > > <vargas.correa.rafael@> wrote:
                    > > > > > >
                    > > > > > I am very
                    > > > > > > interested in researching for the larger size, less resolution
                    > > > > approach for
                    > > > > > > industrial design purposes.know if its possible
                    > > > > > > to acquire a 2ft printable bed size area with good results etc.
                    > > > > > The problem is the exposure time per layer.many of the guys
                    > > > > > are working with object sizes around 100 mm, and layer cycle
                    > > > > > times under 10 seconds. Some of them now have exposures of just
                    > > > > > a FEW seconds with the latest resins from SpotA. That is a huge
                    > > > > improvement over a few years ago.
                    > > > > >
                    > > > > > When scaling exposure time, it goes as the square of linear
                    > > dimension.
                    > > > > > So, if you double the linear dimension, the exposure required is 4 X
                    > > as
                    > > > > long. Now, to scale a 2 second exposure at 100 mm to a linear
                    > > dimension of
                    > > > > 2 feet, that comes to ~600mm, or 6X the dimension.
                    > > > > > So, 6 x 6 = 36, and the exposure would be 72 seconds. Well, not as
                    > > > > > bad as I thought! There may be object-to-bed sticking problems
                    > > > > > with an object this size, you might have to go with the top-down
                    > > > > > build instead of the glass bottomed vat scheme that is used by a
                    > > > > > lot of our group. (The sticking problem may not exist, but there
                    > > could
                    > > > > be problems casting the sylguard to the vat bottom, it might shrink and
                    > > > > peel or something.) Also, these objects tend to shrink, and a resilient
                    > > > > base needs to be built on the build platform to accommodate the
                    > > shrinkage,
                    > > > > or the model breaks free from the platform as it is being built. I
                    > > assume
                    > > > > this problem has to get worse with larger objects. If it just barely
                    > > works
                    > > > > at 100 mm, it is going to be a real bear at 600 mm.
                    > > > > >
                    > > > > > These are just some concerns that occur to me, a reader of this group
                    > > > > > with no experience (so far) in the field.
                    > > > > >
                    > > > > > Jon
                    > > > > >
                    > > > >
                    > > > >
                    > > > >
                    > > >
                    > >
                    > >
                    > >
                    >


                  • bobgarrish
                    They re already around, just in theatre-sizes (and powers!). It s cool, though, as they re still a fraction of the cost of a commercial DLP printer :) If I
                    Message 9 of 10 , Apr 11 5:34 AM
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                      They're already around, just in theatre-sizes (and powers!). It's cool, though, as they're still a fraction of the cost of a commercial DLP printer :)

                      If I ever got a larger-format DLP printer working, it'd be very tempting to get one and try to 'work off' the cost!

                      --- In diy_3d_printing_and_fabrication@yahoogroups.com, travis serio <travisserio@...> wrote:
                      >
                      > And 4k is coming, too! :)
                      >
                      >
                      >
                    • travis serio
                      Yeah if you dont mind spending 10 to 50 grand on one. But it wont be too long before 4k becomes the new 1080p.
                      Message 10 of 10 , Apr 11 6:30 AM
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                        Yeah if you dont mind spending 10 to 50 grand on one. But it wont be too long before 4k becomes the new 1080p. 


                        On Thu, Apr 11, 2013 at 8:34 AM, bobgarrish <bobgarrish@...> wrote:
                         

                        They're already around, just in theatre-sizes (and powers!). It's cool, though, as they're still a fraction of the cost of a commercial DLP printer :)

                        If I ever got a larger-format DLP printer working, it'd be very tempting to get one and try to 'work off' the cost!

                        --- In diy_3d_printing_and_fabrication@yahoogroups.com, travis serio <travisserio@...> wrote:
                        >
                        > And 4k is coming, too! :)
                        >
                        >
                        >


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