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I've got focus.

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  • vrsculptor@hotmail.com
    Look at photos that I just posted in vrsculptor photo folder. What I did was remove focus ring from projector and add a stop ring too it. This allowed me to
    Message 1 of 12 , Sep 3, 2011
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      Look at photos that I just posted in vrsculptor photo folder. What I did was remove focus ring from projector and add a stop ring too it. This allowed me to manually adjust and calibrate the image size and focus to the size I wanted. The ring and shims pictured are required to insure that the focus ring is not tilted. The ratio of barrel length to diameter is nowhere near ideal and without some intervention the focus lens will tilt causing distortion.

      I was able to get a 7 inch wide picture with the projector about 7 inches from image. No bi-focals required and image looks good.

      Next up... I don't need no stinkin 80/20.

      Roger
    • vrsculptor@hotmail.com
      That is a good question that deserves a thoughtful answer. Please keep in mind that for me this is a hobby and being retired time spent is not an economic
      Message 2 of 12 , Sep 3, 2011
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        That is a good question that deserves a thoughtful answer. Please keep in mind that for me this is a hobby and being retired time spent is not an economic consideration.

        The requirements for resolution depend on the use for which the tool is used and accuracy costs effort and money. If you are doing prototype work that requires precision as in an assembly that requires snap fits a tolerance of a couple of thousands is required. If you are producing patterns for castings or you expect secondary machining resolution is not so important. I'm looking at doing patterns (via silicone) for lost wax and resin castings. The patterns will be post processed as needed.

        I'm also very curious (as you pointed out) the implications of size on curing time. The UV light drops with the square of the area. A .007 inch thick layer will take longer to cure than a couple of microns but this may be offset by the number of layers required. I honestly don't know.

        Speed, if you doing your own projects, is not much of a consideration. If I'm doing profiling on the mill a job may run for many hours. With a simple machine like a DLP printer parts can run overnight. I feel much safer letting this run unattended than my mill or a RepRap machine.

        KISS. Another thing I've learned along the way is that while learning and experimenting it is often useful to go with the simplest mechanism that will work and if you find it useful undertake a more sophisticated project. I started with CNC'ing a HF mini-mill and ended up converting a very large 7000# mill.

        I bought Dymax for $150/liter. I think that works out to about $2.50 a cubic inch. I can afford that at least as far as testing goes. With luck something cheaper may come along.

        I think at even .007 resolution a DLP printer might be better than a RepRap. I don't think that the state of the art in either RepRap or our DLP printers has reached the point that they justify sophisticated solutions. Cost of this project, because of a well stocked junk box, will be less that $300. That is pretty low cost in terms of education and entertainment and I've already learned much more than I wanted to know about light sources and optics.

        If all goes well who knows. I may build a sliding DLP based system with a huge build area and high resolution.

        Roger

        PS. Was even able to focus to a smaller size using method described. I knwo I hit 4 inches.

        --- In diy_3d_printing_and_fabrication@yahoogroups.com, "techartisan" <metalations@...> wrote:
        >
        > Im not trying to put your work down, I am just curious about your build intention.
        > you are using an xp7030...1024X768 projector....
        > At 7 inch wide your xy voxel dimension .0068in, .172mm or 173.72 microns....seems rather large in comparison to Eteks 43-73 typical xy micron dimension.
        > Is there a reason youve chosen to go low res? This is essentially reprap build resolution, at a much higher material cost. Beyond limiting your surface resolution, have you considered the effect this dispersion will have on layer cure time? Given the (prolonged exposure time:full layer build) it would be interesting to see how your build time would compare to a reprap on the same part.
        >
        > Again not criticizing, just curious why youve made this choice as most see DLP as a way to enhanced part resolution at the expense of heightened material costs.
        >
      • Fernando
        This is something I have been giving some thought and doing some work as well. While modifying my projector s optics, I have managed to forward the optics
        Message 3 of 12 , Sep 4, 2011
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          This is something I have been giving some thought and doing some work as
          well. While modifying my projector's optics, I have managed to forward
          the optics module for about 2mm within the flange that supports it,
          which provided the possibility to focus at significantly closer ranges:

          From stock, my DLP was able to produce a smallest area of 230x280mm at
          530mm throw distance.

          After modification I am now able to throw images of
          135x110mm at 230mm distance
          200x150mm at 350mm distance
          230x280mm at 475mm distance

          This gives me a nice range of precisions and sizes to work with and has
          urged me to modify my printer structure to accommodate a rail to support
          the DLP. It's a pretty simple mod and this way I will be able to adjust
          size and resolution to suit my needs. The only caveat here would be
          calibrating dimensions from the 3D model to the print stage.

          NOTE: while fiddling around with the (incredibly filthy) optics to clean
          them up and shorten the throw I have introduced some distortion. I will
          have to carefully tweak around the positioning of the lens module to
          correct it.

          In the meantime, my In-laws have arrived for a vacation and all the DIY
          work is grinding to a halt.........


          On Sat, 2011-09-03 at 19:17 +0000, vrsculptor@... wrote:
          >
          > That is a good question that deserves a thoughtful answer. Please keep
          > in mind that for me this is a hobby and being retired time spent is
          > not an economic consideration.
          >
          > The requirements for resolution depend on the use for which the tool
          > is used and accuracy costs effort and money. If you are doing
          > prototype work that requires precision as in an assembly that requires
          > snap fits a tolerance of a couple of thousands is required. If you are
          > producing patterns for castings or you expect secondary machining
          > resolution is not so important. I'm looking at doing patterns (via
          > silicone) for lost wax and resin castings. The patterns will be post
          > processed as needed.
          >
          > I'm also very curious (as you pointed out) the implications of size on
          > curing time. The UV light drops with the square of the area. A .007
          > inch thick layer will take longer to cure than a couple of microns but
          > this may be offset by the number of layers required. I honestly don't
          > know.
          >
          > Speed, if you doing your own projects, is not much of a consideration.
          > If I'm doing profiling on the mill a job may run for many hours. With
          > a simple machine like a DLP printer parts can run overnight. I feel
          > much safer letting this run unattended than my mill or a RepRap
          > machine.
          >
          > KISS. Another thing I've learned along the way is that while learning
          > and experimenting it is often useful to go with the simplest mechanism
          > that will work and if you find it useful undertake a more
          > sophisticated project. I started with CNC'ing a HF mini-mill and ended
          > up converting a very large 7000# mill.
          >
          > I bought Dymax for $150/liter. I think that works out to about $2.50 a
          > cubic inch. I can afford that at least as far as testing goes. With
          > luck something cheaper may come along.
          >
          > I think at even .007 resolution a DLP printer might be better than a
          > RepRap. I don't think that the state of the art in either RepRap or
          > our DLP printers has reached the point that they justify sophisticated
          > solutions. Cost of this project, because of a well stocked junk box,
          > will be less that $300. That is pretty low cost in terms of education
          > and entertainment and I've already learned much more than I wanted to
          > know about light sources and optics.
          >
          > If all goes well who knows. I may build a sliding DLP based system
          > with a huge build area and high resolution.
          >
          > Roger
          >
          > PS. Was even able to focus to a smaller size using method described. I
          > knwo I hit 4 inches.
          >
          > --- In diy_3d_printing_and_fabrication@yahoogroups.com, "techartisan"
          > <metalations@...> wrote:
          > >
          > > Im not trying to put your work down, I am just curious about your
          > build intention.
          > > you are using an xp7030...1024X768 projector....
          > > At 7 inch wide your xy voxel dimension .0068in, .172mm or 173.72
          > microns....seems rather large in comparison to Eteks 43-73 typical xy
          > micron dimension.
          > > Is there a reason youve chosen to go low res? This is essentially
          > reprap build resolution, at a much higher material cost. Beyond
          > limiting your surface resolution, have you considered the effect this
          > dispersion will have on layer cure time? Given the (prolonged exposure
          > time:full layer build) it would be interesting to see how your build
          > time would compare to a reprap on the same part.
          > >
          > > Again not criticizing, just curious why youve made this choice as
          > most see DLP as a way to enhanced part resolution at the expense of
          > heightened material costs.
          > >
          >
          >
          >
          >
          >
        • vrsculptor@hotmail.com
          Fernando, I tried shimming the lens assembly out and got distortion. Admittedly my shimming was on the crude side and may have been the problem. That is why I
          Message 4 of 12 , Sep 4, 2011
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            Fernando,
            I tried shimming the lens assembly out and got distortion. Admittedly my shimming was on the crude side and may have been the problem. That is why I ended up shimming the focusing ring. Your solution is much better, if you can fix the distortion, as you have a variable throw while mine if fixed.

            Please keep us posted.

            Roger

            > This is something I have been giving some thought and doing some work as
            > well. While modifying my projector's optics, I have managed to forward
            > the optics module for about 2mm within the flange that supports it,
            > which provided the possibility to focus at significantly closer ranges:
            >
            > From stock, my DLP was able to produce a smallest area of 230x280mm at
            > 530mm throw distance.
            >
            > After modification I am now able to throw images of
            > 135x110mm at 230mm distance
            > 200x150mm at 350mm distance
            > 230x280mm at 475mm distance
            >
            > This gives me a nice range of precisions and sizes to work with and has
            > urged me to modify my printer structure to accommodate a rail to support
            > the DLP. It's a pretty simple mod and this way I will be able to adjust
            > size and resolution to suit my needs. The only caveat here would be
            > calibrating dimensions from the 3D model to the print stage.
            >
            > NOTE: while fiddling around with the (incredibly filthy) optics to clean
            > them up and shorten the throw I have introduced some distortion. I will
            > have to carefully tweak around the positioning of the lens module to
            > correct it.
            >
            > In the meantime, my In-laws have arrived for a vacation and all the DIY
            > work is grinding to a halt.........
            >
          • Fernando
            Oh dear... Everything was going so nice and I have majorly fuc#ed up! I was so happy because I had tweaked the lens assembly positioning in a way that the
            Message 5 of 12 , Sep 4, 2011
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              Oh dear...
              Everything was going so nice and I have majorly fuc#ed up!
              I was so happy because I had tweaked the lens assembly positioning in a
              way that the distortion was gone and I was trying out throw distances
              with the color wheel out of the way. Everything was just rosy!

              But then I noticed there was a band of dirt on the left side of the
              picture and I assumed there must have been a spot I missed cleaning in
              the optics. The only part I hadn't yet thoroughly cleaned was the light
              integration tunnel. In a projector that is a rectangular section, hollow
              (or solid) tunnel that catches the light from the lamp and carries it to
              the DMD module. So I went and used some lens cleaning fluid and a cotton
              stick to try and clean it.
              The bad surprise was when the cotton tip came back out with some alu
              scales on it, looking suspiciously like mirror residue to me. So I
              quickly assembled the projector back, switched it on and indeed, the
              image was almost completely gone!!! I cannot believe I just destroyed my
              projector just before the all important resin curing tests... I'm so
              frustrated right now I could burn the damn filthy projector in a pyre!


              On Sun, 2011-09-04 at 14:42 +0000, vrsculptor@... wrote:
              >
              > Fernando,
              > I tried shimming the lens assembly out and got distortion. Admittedly
              > my shimming was on the crude side and may have been the problem. That
              > is why I ended up shimming the focusing ring. Your solution is much
              > better, if you can fix the distortion, as you have a variable throw
              > while mine if fixed.
              >
              > Please keep us posted.
              >
              > Roger
              >
              > > This is something I have been giving some thought and doing some
              > work as
              > > well. While modifying my projector's optics, I have managed to
              > forward
              > > the optics module for about 2mm within the flange that supports it,
              > > which provided the possibility to focus at significantly closer
              > ranges:
              > >
              > > From stock, my DLP was able to produce a smallest area of 230x280mm
              > at
              > > 530mm throw distance.
              > >
              > > After modification I am now able to throw images of
              > > 135x110mm at 230mm distance
              > > 200x150mm at 350mm distance
              > > 230x280mm at 475mm distance
              > >
              > > This gives me a nice range of precisions and sizes to work with and
              > has
              > > urged me to modify my printer structure to accommodate a rail to
              > support
              > > the DLP. It's a pretty simple mod and this way I will be able to
              > adjust
              > > size and resolution to suit my needs. The only caveat here would be
              > > calibrating dimensions from the 3D model to the print stage.
              > >
              > > NOTE: while fiddling around with the (incredibly filthy) optics to
              > clean
              > > them up and shorten the throw I have introduced some distortion. I
              > will
              > > have to carefully tweak around the positioning of the lens module to
              > > correct it.
              > >
              > > In the meantime, my In-laws have arrived for a vacation and all the
              > DIY
              > > work is grinding to a halt.........
              > >
              >
              >
              >
              >
              >
            • Fernando
              OK, damage limitation mode: I just bought myself another HP VP6121 projector for parts from ebay. I will be more comfortable tinkering around on the projector
              Message 6 of 12 , Sep 4, 2011
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                OK, damage limitation mode:
                I just bought myself another HP VP6121 projector for parts from ebay.
                I will be more comfortable tinkering around on the projector with the
                knowledge of having replacement parts to fall back upon.

                In the meantime, I will have to go back to the test rig for making the
                initial resin system comparisons. This will all set me back somewhat,
                but what's a kid to do...


                On Sun, 2011-09-04 at 18:42 +0200, Fernando wrote:
                > Oh dear...
                > Everything was going so nice and I have majorly fuc#ed up!
                > I was so happy because I had tweaked the lens assembly positioning in a
                > way that the distortion was gone and I was trying out throw distances
                > with the color wheel out of the way. Everything was just rosy!
                >
                > But then I noticed there was a band of dirt on the left side of the
                > picture and I assumed there must have been a spot I missed cleaning in
                > the optics. The only part I hadn't yet thoroughly cleaned was the light
                > integration tunnel. In a projector that is a rectangular section, hollow
                > (or solid) tunnel that catches the light from the lamp and carries it to
                > the DMD module. So I went and used some lens cleaning fluid and a cotton
                > stick to try and clean it.
                > The bad surprise was when the cotton tip came back out with some alu
                > scales on it, looking suspiciously like mirror residue to me. So I
                > quickly assembled the projector back, switched it on and indeed, the
                > image was almost completely gone!!! I cannot believe I just destroyed my
                > projector just before the all important resin curing tests... I'm so
                > frustrated right now I could burn the damn filthy projector in a pyre!
                >
                >
                > On Sun, 2011-09-04 at 14:42 +0000, vrsculptor@... wrote:
                > >
                > > Fernando,
                > > I tried shimming the lens assembly out and got distortion. Admittedly
                > > my shimming was on the crude side and may have been the problem. That
                > > is why I ended up shimming the focusing ring. Your solution is much
                > > better, if you can fix the distortion, as you have a variable throw
                > > while mine if fixed.
                > >
                > > Please keep us posted.
                > >
                > > Roger
                > >
                > > > This is something I have been giving some thought and doing some
                > > work as
                > > > well. While modifying my projector's optics, I have managed to
                > > forward
                > > > the optics module for about 2mm within the flange that supports it,
                > > > which provided the possibility to focus at significantly closer
                > > ranges:
                > > >
                > > > From stock, my DLP was able to produce a smallest area of 230x280mm
                > > at
                > > > 530mm throw distance.
                > > >
                > > > After modification I am now able to throw images of
                > > > 135x110mm at 230mm distance
                > > > 200x150mm at 350mm distance
                > > > 230x280mm at 475mm distance
                > > >
                > > > This gives me a nice range of precisions and sizes to work with and
                > > has
                > > > urged me to modify my printer structure to accommodate a rail to
                > > support
                > > > the DLP. It's a pretty simple mod and this way I will be able to
                > > adjust
                > > > size and resolution to suit my needs. The only caveat here would be
                > > > calibrating dimensions from the 3D model to the print stage.
                > > >
                > > > NOTE: while fiddling around with the (incredibly filthy) optics to
                > > clean
                > > > them up and shorten the throw I have introduced some distortion. I
                > > will
                > > > have to carefully tweak around the positioning of the lens module to
                > > > correct it.
                > > >
                > > > In the meantime, my In-laws have arrived for a vacation and all the
                > > DIY
                > > > work is grinding to a halt.........
                > > >
                > >
                > >
                > >
                > >
                > >
                >
              • Fernando
                That is indeed interesting! Did you measure any minimum throw distances for that projector off the shelve? You may have published this already but you know how
                Message 7 of 12 , Sep 4, 2011
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                  That is indeed interesting! Did you measure any minimum throw distances
                  for that projector off the shelve? You may have published this already
                  but you know how I tend to oversee things sometimes ;)
                  My brother is thinking in building a 3D printer after me and I may want
                  to indicate him as many parts that do not need tinkering as possible.

                  Anyway, on my broken DLP, I try to be philosophical: I see this current
                  build as a learning project, and there's already so much more I know now
                  than I did 6 months ago. It's incredible when I go back to my notes from
                  then, I was so naïve! I'm sure that for the second build for my brother
                  all will be a lot more straight-forward.

                  Today's take home message: don't mess with your light integration
                  tunnel! And find a projector that keeps itself clean.

                  On Sun, 2011-09-04 at 17:35 +0000, techartisan wrote:
                  >
                  > Bummer about your damage. Hope your back up and running quickly.
                  >
                  > This information obviously comes a bit too late....but for those who
                  > have not yet purchased a projector...
                  >
                  > Most projectors simply run their cooling intake through a filter
                  > hoping to catch dust....obviously this is not 100% effective....and
                  > adds maintenance to the projector. Optoma projectors are designed in a
                  > way that prevents the filth issues many other projectors have. Im not
                  > certain the specific details of the air route...but they are
                  > filter-less and maintenance free by design..I bought my projectors
                  > new....and havent bothered to open them up...but I was told by a
                  > service tech that the optomas he has worked on were very clean
                  > internally. Just something to consider.
                  >
                  > --- In diy_3d_printing_and_fabrication@yahoogroups.com, Fernando
                  > <spacecaptain@...> wrote:
                  > >
                  > > OK, damage limitation mode:
                  > > I just bought myself another HP VP6121 projector for parts from
                  > ebay.
                  > > I will be more comfortable tinkering around on the projector with
                  > the
                  > > knowledge of having replacement parts to fall back upon.
                  > >
                  > > In the meantime, I will have to go back to the test rig for making
                  > the
                  > > initial resin system comparisons. This will all set me back
                  > somewhat,
                  > > but what's a kid to do...
                  > >
                  > >
                  > > On Sun, 2011-09-04 at 18:42 +0200, Fernando wrote:
                  > > > Oh dear...
                  > > > Everything was going so nice and I have majorly fuc#ed up!
                  > > > I was so happy because I had tweaked the lens assembly positioning
                  > in a
                  > > > way that the distortion was gone and I was trying out throw
                  > distances
                  > > > with the color wheel out of the way. Everything was just rosy!
                  > > >
                  > > > But then I noticed there was a band of dirt on the left side of
                  > the
                  > > > picture and I assumed there must have been a spot I missed
                  > cleaning in
                  > > > the optics. The only part I hadn't yet thoroughly cleaned was the
                  > light
                  > > > integration tunnel. In a projector that is a rectangular section,
                  > hollow
                  > > > (or solid) tunnel that catches the light from the lamp and carries
                  > it to
                  > > > the DMD module. So I went and used some lens cleaning fluid and a
                  > cotton
                  > > > stick to try and clean it.
                  > > > The bad surprise was when the cotton tip came back out with some
                  > alu
                  > > > scales on it, looking suspiciously like mirror residue to me. So I
                  > > > quickly assembled the projector back, switched it on and indeed,
                  > the
                  > > > image was almost completely gone!!! I cannot believe I just
                  > destroyed my
                  > > > projector just before the all important resin curing tests... I'm
                  > so
                  > > > frustrated right now I could burn the damn filthy projector in a
                  > pyre!
                  > > >
                  > > >
                  > > > On Sun, 2011-09-04 at 14:42 +0000, vrsculptor@... wrote:
                  > > > >
                  > > > > Fernando,
                  > > > > I tried shimming the lens assembly out and got distortion.
                  > Admittedly
                  > > > > my shimming was on the crude side and may have been the problem.
                  > That
                  > > > > is why I ended up shimming the focusing ring. Your solution is
                  > much
                  > > > > better, if you can fix the distortion, as you have a variable
                  > throw
                  > > > > while mine if fixed.
                  > > > >
                  > > > > Please keep us posted.
                  > > > >
                  > > > > Roger
                  > > > >
                  > > > > > This is something I have been giving some thought and doing
                  > some
                  > > > > work as
                  > > > > > well. While modifying my projector's optics, I have managed to
                  > > > > forward
                  > > > > > the optics module for about 2mm within the flange that
                  > supports it,
                  > > > > > which provided the possibility to focus at significantly
                  > closer
                  > > > > ranges:
                  > > > > >
                  > > > > > From stock, my DLP was able to produce a smallest area of
                  > 230x280mm
                  > > > > at
                  > > > > > 530mm throw distance.
                  > > > > >
                  > > > > > After modification I am now able to throw images of
                  > > > > > 135x110mm at 230mm distance
                  > > > > > 200x150mm at 350mm distance
                  > > > > > 230x280mm at 475mm distance
                  > > > > >
                  > > > > > This gives me a nice range of precisions and sizes to work
                  > with and
                  > > > > has
                  > > > > > urged me to modify my printer structure to accommodate a rail
                  > to
                  > > > > support
                  > > > > > the DLP. It's a pretty simple mod and this way I will be able
                  > to
                  > > > > adjust
                  > > > > > size and resolution to suit my needs. The only caveat here
                  > would be
                  > > > > > calibrating dimensions from the 3D model to the print stage.
                  > > > > >
                  > > > > > NOTE: while fiddling around with the (incredibly filthy)
                  > optics to
                  > > > > clean
                  > > > > > them up and shorten the throw I have introduced some
                  > distortion. I
                  > > > > will
                  > > > > > have to carefully tweak around the positioning of the lens
                  > module to
                  > > > > > correct it.
                  > > > > >
                  > > > > > In the meantime, my In-laws have arrived for a vacation and
                  > all the
                  > > > > DIY
                  > > > > > work is grinding to a halt.........
                  > > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > >
                  > >
                  >
                  >
                  >
                  >
                  >
                • vrsculptor@hotmail.com
                  My HP 7030 s stock minimum throw was about 14 before shimming the focus ring. I know it will go much smaller that 7 image. Roger
                  Message 8 of 12 , Sep 4, 2011
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                    My HP 7030's stock minimum throw was about 14" before shimming the focus ring. I know it will go much smaller that 7" image.

                    Roger

                    > That is indeed interesting! Did you measure any minimum throw distances
                    > for that projector off the shelve? You may have published this already
                    > but you know how I tend to oversee things sometimes ;)
                    > My brother is thinking in building a 3D printer after me and I may want
                    > to indicate him as many parts that do not need tinkering as possible.
                    >
                  • Spacecaptain
                    Roger I have a question: Why don t you try and add a spacer between your lens holder and your lens module?
                    Message 9 of 12 , Sep 5, 2011
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                      Roger I have a question:
                      Why don't you try and add a spacer between your lens holder and your lens module?
                      http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view

                      This way you would keep your lenses focussing and zooming abilities as well as achieving those close throw distances we are looking for.

                      BTW: My replacement parts projector should arrive in 2-4 days, lots faster than I had expected!


                      On 09/04/2011 10:34 PM, vrsculptor@... wrote:
                       

                      My HP 7030's stock minimum throw was about 14" before shimming the focus ring. I know it will go much smaller that 7" image.

                      Roger

                      > That is indeed interesting! Did you measure any minimum throw distances
                      > for that projector off the shelve? You may have published this already
                      > but you know how I tend to oversee things sometimes ;)
                      > My brother is thinking in building a 3D printer after me and I may want
                      > to indicate him as many parts that do not need tinkering as possible.
                      >


                    • vrsculptor@hotmail.com
                      I tried that and got distortion. It may have been that my shimming wasn t perfect or the relationship of the lens to the optics in the projector. Shimming the
                      Message 10 of 12 , Sep 5, 2011
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                        I tried that and got distortion. It may have been that my shimming wasn't perfect or the relationship of the lens to the optics in the projector. Shimming the focus ring gave me no distortion.

                        Roger

                        --- In diy_3d_printing_and_fabrication@yahoogroups.com, Spacecaptain <spacecaptain@...> wrote:
                        >
                        > Roger I have a question:
                        > Why don't you try and add a spacer between your lens holder and your
                        > lens module?
                        > <http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view>http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view
                        >
                        > This way you would keep your lenses focussing and zooming abilities as
                        > well as achieving those close throw distances we are looking for.
                        >
                        > BTW: My replacement parts projector should arrive in 2-4 days, lots
                        > faster than I had expected!
                        >
                        >
                        > On 09/04/2011 10:34 PM, vrsculptor@... wrote:
                        > >
                        > > My HP 7030's stock minimum throw was about 14" before shimming the
                        > > focus ring. I know it will go much smaller that 7" image.
                        > >
                        > > Roger
                        > >
                        > > > That is indeed interesting! Did you measure any minimum throw distances
                        > > > for that projector off the shelve? You may have published this already
                        > > > but you know how I tend to oversee things sometimes ;)
                        > > > My brother is thinking in building a 3D printer after me and I may want
                        > > > to indicate him as many parts that do not need tinkering as possible.
                        > > >
                        > >
                        > >
                        >
                      • Spacecaptain
                        Yeah, it really is quite sensitive at that point. I have been able to adjust mine because the lens module is mounted in a cylindrical flange with 3 screws at
                        Message 11 of 12 , Sep 5, 2011
                        • 0 Attachment
                          Yeah, it really is quite sensitive at that point. I have been able to adjust mine because the lens module is mounted in a cylindrical flange with 3 screws at 120º intervals. This way I was able to tweak the position so that the distortion was removed.

                          In your case, what I have been thinking is to have some kind of a spring loaded screw system instead of the shimming, so that you could easily adjust the distortion with some screw-turns. But these are ideas that I would probably only be able to put into effect once I start building a deconstructed DLP. There's room for a number of improvements from a compact DLP design to a device that can be easily modded:
                          - dichroic filters instead of the color wheel for pigmented resin systems or alternate PIs
                          - tapered light integrating tunnels for more light output
                          - adjustable lens modules for a range of throw distances, sizes and resolutions
                          - better ventilation for keeping the inside clean of dust
                          - better electronic components geometry to make the printer envelope less bulky


                          On 09/05/2011 04:44 PM, vrsculptor@... wrote:
                           

                          I tried that and got distortion. It may have been that my shimming wasn't perfect or the relationship of the lens to the optics in the projector. Shimming the focus ring gave me no distortion.

                          Roger

                          --- In diy_3d_printing_and_fabrication@yahoogroups.com, Spacecaptain <spacecaptain@...> wrote:
                          >
                          > Roger I have a question:
                          > Why don't you try and add a spacer between your lens holder and your
                          > lens module?
                          > <http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view>http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view
                          >
                          > This way you would keep your lenses focussing and zooming abilities as
                          > well as achieving those close throw distances we are looking for.
                          >
                          > BTW: My replacement parts projector should arrive in 2-4 days, lots
                          > faster than I had expected!
                          >
                          >
                          > On 09/04/2011 10:34 PM, vrsculptor@... wrote:
                          > >
                          > > My HP 7030's stock minimum throw was about 14" before shimming the
                          > > focus ring. I know it will go much smaller that 7" image.
                          > >
                          > > Roger
                          > >
                          > > > That is indeed interesting! Did you measure any minimum throw distances
                          > > > for that projector off the shelve? You may have published this already
                          > > > but you know how I tend to oversee things sometimes ;)
                          > > > My brother is thinking in building a 3D printer after me and I may want
                          > > > to indicate him as many parts that do not need tinkering as possible.
                          > > >
                          > >
                          > >
                          >


                        • vrsculptor@hotmail.com
                          I had given some thought to an adjustable shimming solution (circular wedge shaped shims that mimic the original ramps) but thought better of it. In terms of
                          Message 12 of 12 , Sep 5, 2011
                          • 0 Attachment
                            I had given some thought to an adjustable shimming solution (circular wedge shaped shims that mimic the original ramps) but thought better of it. In terms of accuracy and repeatability fixed shims seemed best. If the shimming was done on the base of the lens you may have to do a lot of disassembly to try different settings. Shimming the focus ring took no additional disassembly and as lens is in a vertical position and held square by shims and gravity the focus lens just sits there and can be easily removed and the shims adjusted.

                            If shimming the base works on your projector then adjustments are not required as the stock zoom will do the job.

                            I don't have strong feelings about this and my judgement may have been swayed by my initial failure to shim the base of the lens. What ever works is OK.

                            Roger

                            --- In diy_3d_printing_and_fabrication@yahoogroups.com, Spacecaptain <spacecaptain@...> wrote:
                            >
                            > Yeah, it really is quite sensitive at that point. I have been able to
                            > adjust mine because the lens module is mounted in a cylindrical flange
                            > with 3 screws at 120º intervals. This way I was able to tweak the
                            > position so that the distortion was removed.
                            >
                            > In your case, what I have been thinking is to have some kind of a spring
                            > loaded screw system instead of the shimming, so that you could easily
                            > adjust the distortion with some screw-turns. But these are ideas that I
                            > would probably only be able to put into effect once I start building a
                            > deconstructed DLP. There's room for a number of improvements from a
                            > compact DLP design to a device that can be easily modded:
                            > - dichroic filters instead of the color wheel for pigmented resin
                            > systems or alternate PIs
                            > - tapered light integrating tunnels for more light output
                            > - adjustable lens modules for a range of throw distances, sizes and
                            > resolutions
                            > - better ventilation for keeping the inside clean of dust
                            > - better electronic components geometry to make the printer envelope
                            > less bulky
                            >
                            >
                            > On 09/05/2011 04:44 PM, vrsculptor@... wrote:
                            > >
                            > > I tried that and got distortion. It may have been that my shimming
                            > > wasn't perfect or the relationship of the lens to the optics in the
                            > > projector. Shimming the focus ring gave me no distortion.
                            > >
                            > > Roger
                            > >
                            > > --- In diy_3d_printing_and_fabrication@yahoogroups.com
                            > > <mailto:diy_3d_printing_and_fabrication%40yahoogroups.com>,
                            > > Spacecaptain <spacecaptain@> wrote:
                            > > >
                            > > > Roger I have a question:
                            > > > Why don't you try and add a spacer between your lens holder and your
                            > > > lens module?
                            > > >
                            > > <http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view>http://groups.yahoo.com/group/diy_3d_printing_and_fabrication/photos/recent/631409801/view
                            > > >
                            > > > This way you would keep your lenses focussing and zooming abilities as
                            > > > well as achieving those close throw distances we are looking for.
                            > > >
                            > > > BTW: My replacement parts projector should arrive in 2-4 days, lots
                            > > > faster than I had expected!
                            > > >
                            > > >
                            > > > On 09/04/2011 10:34 PM, vrsculptor@ wrote:
                            > > > >
                            > > > > My HP 7030's stock minimum throw was about 14" before shimming the
                            > > > > focus ring. I know it will go much smaller that 7" image.
                            > > > >
                            > > > > Roger
                            > > > >
                            > > > > > That is indeed interesting! Did you measure any minimum throw
                            > > distances
                            > > > > > for that projector off the shelve? You may have published this
                            > > already
                            > > > > > but you know how I tend to oversee things sometimes ;)
                            > > > > > My brother is thinking in building a 3D printer after me and I
                            > > may want
                            > > > > > to indicate him as many parts that do not need tinkering as
                            > > possible.
                            > > > > >
                            > > > >
                            > > > >
                            > > >
                            > >
                            > >
                            >
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