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  • #9552
    AvatarGiM
    Participant
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      First of all I would like to extend a warm greeting to you all.
      First of all I would like to extend a warm greeting to you all.
      First of all I would like to extend a warm greeting to you all, ho 60 years, First of all I would like to extend a warm greeting to you all, First of all I would like to extend a warm greeting to you all.
      First of all I would like to extend a warm greeting to you all.
      First of all I would like to extend a warm greeting to you all. First of all I would like to extend a warm greeting to you all, First of all I would like to extend a warm greeting to you all. First of all I would like to extend a warm greeting to you all. In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me.
      In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me, In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me ( In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me ), In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me 200 mm diametro.
      In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me (In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me, In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me, In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me, In the meantime I got some books that explained how to work glass but the difficulty of finding the materials has always blocked me). in conclusion, everything was designed and built by one of us who by the way is a mechanical engineer, everything was designed and built by one of us who by the way is a mechanical engineer.
      everything was designed and built by one of us who by the way is a mechanical engineer.
      everything was designed and built by one of us who by the way is a mechanical engineer (everything was designed and built by one of us who by the way is a mechanical engineer, mechanics, everything was designed and built by one of us who by the way is a mechanical engineer) everything was designed and built by one of us who by the way is a mechanical engineer.
      everything was designed and built by one of us who by the way is a mechanical engineer, everything was designed and built by one of us who by the way is a mechanical engineer, everything was designed and built by one of us who by the way is a mechanical engineer, everything was designed and built by one of us who by the way is a mechanical engineer. All self-financing except for the initial purchase he abrasives.
      All self-financing except for the initial purchase he abrasives. All self-financing except for the initial purchase he abrasives. All self-financing except for the initial purchase he abrasives.
      All self-financing except for the initial purchase he abrasives. All self-financing except for the initial purchase he abrasives, All self-financing except for the initial purchase he abrasives, All self-financing except for the initial purchase he abrasives.
      It was during my long hospital stays and sick days at home that I discovered the Grattavetro website. It was during my long hospital stays and sick days at home that I discovered the Grattavetro website!
      It was during my long hospital stays and sick days at home that I discovered the Grattavetro website, It was during my long hospital stays and sick days at home that I discovered the Grattavetro website. It was during my long hospital stays and sick days at home that I discovered the Grattavetro website, It was during my long hospital stays and sick days at home that I discovered the Grattavetro website.
      It was during my long hospital stays and sick days at home that I discovered the Grattavetro website 2016 we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss. we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss.
      we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss.
      we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss ( we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss ) we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss. we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss.
      we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss 300 mm.
      we were able to obtain a mirror worked up to just over λ / 4 and with a barely acceptable degree of gloss.
      I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you..
      I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you..
      I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you..
      Giuseppe Mura

      #9553
      AvatarGiulio TiberinI
      Moderator
        • Offline

        Welcome Giuseppe!!
        Yours is very interesting “curriculum” of self-builder!
        We “glass scratcher” we always thought that “out there” surely there were beautiful people like yours; curious and interested in tackling demanding challenges that the majority avoids in favor of a comfortable lack of self-confidence, and easy and comfortable but expensive “everything and immediately”…All features that usually prelude to a short duration of interest.

        If you think you could certainly open an interesting discussion to describe and witness the project of your rotating plan, which in my opinion, given the presence of the arm motorization, it is configured more like a real complete machine rather than a simple rotating table.

        I believe that a speech on machining is still very interesting, even if my very personal thought is in favor of the simpler and safer manual processing, but only because I see that generally, the machining of a mirror is much more demanding and unsafe than a freehand realization.

        And this is because in order to master the adjustments of a machine to perform a good surface, you must first have managed to juggle well with several freehand realizations.

        It would seem a contradiction, but my reasoning comes from the fact that the car, due to its processing speed e “precision” repetition of its machining strokes, it is heavily disadvantaged compared to the more imprecise manual processing.

        And this is because the MINIMUM tolerance of optical processing is only of 68,75 millionths of a millimeter, and therefore a machine by its nature has the greatest probability of making a wrong surface by quickly adding up its smallest errors making them become very large in a very short time, while instead in the imprecise manual processing they would have been in the minority, and then automatically canceled by mutual elision, as guaranteed by the statistics of the machining made of miles of machining passes of which each removes only an infinitesimal part of material.

        Hoping to read you soon.
        Still welcome
        Ciao – Giulio

        #9555
        AvatarGiM
        Participant
          • Offline

          I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you.
          I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you., I believe that if you will allow me, I will later intervene in some discussion on the construction of turntables on which I have accumulated some experience and for which I have found solutions that may interest you.. As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required..
          As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required., As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required.. As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required..
          As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required. (As I have already said, working with a machine is certainly very difficult and I do not recommend it to anyone to start with, except perhaps in the roughing phase where great precision is not required.) with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house, with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house, with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house, with whom I continued the work in the garage of the house. with whom I continued the work in the garage of the house, well as already mentioned in the machine built at the school, the top was made to rotate effortlessly at a speed of about one revolution per minute with an engine that at most must have had a few tens of watts of power. well as already mentioned in the machine built at the school, the top was made to rotate effortlessly at a speed of about one revolution per minute with an engine that at most must have had a few tens of watts of power. well as already mentioned in the machine built at the school, the top was made to rotate effortlessly at a speed of about one revolution per minute with an engine that at most must have had a few tens of watts of power, well as already mentioned in the machine built at the school, the top was made to rotate effortlessly at a speed of about one revolution per minute with an engine that at most must have had a few tens of watts of power 80. well as already mentioned in the machine built at the school, the top was made to rotate effortlessly at a speed of about one revolution per minute with an engine that at most must have had a few tens of watts of power. She works and I do other things by simply supervising her work and checking the results from time to time.
          She works and I do other things by simply supervising her work and checking the results from time to time.
          Hello everybody

          #9556
          Massimo MarconiMassimo Marconi
          Moderator
            • Offline

            Hello Joseph, She works and I do other things by simply supervising her work and checking the results from time to time ! She works and I do other things by simply supervising her work and checking the results from time to time, She works and I do other things by simply supervising her work and checking the results from time to time.

            She works and I do other things by simply supervising her work and checking the results from time to time, She works and I do other things by simply supervising her work and checking the results from time to time, She works and I do other things by simply supervising her work and checking the results from time to time. She works and I do other things by simply supervising her work and checking the results from time to time, She works and I do other things by simply supervising her work and checking the results from time to time , any machine optimization / setup errors add up, any machine optimization / setup errors add up, any machine optimization / setup errors add up.

            Anyhow, any machine optimization / setup errors add up ( any machine optimization / setup errors add up ) that still, any machine optimization / setup errors add up, any machine optimization / setup errors add up. any machine optimization / setup errors add up, any machine optimization / setup errors add up.

            #9557
            AvatarGiulio TiberinI
            Moderator
              • Offline

              I agree with Massimo that your writing accompanied by images describing your work is a lot, very interesting!! :good: :good:

              #9562
              AvatarGiM
              Participant
                • Offline

                Hello everybody
                You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far.
                You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far. You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far. You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far. You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far. You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far

                #9563
                Massimo MarconiMassimo Marconi
                Moderator
                  • Offline

                  Hello Joseph, You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far, You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far “You have to excuse me but given my unfamiliarity with the forums I find it difficult to keep faith with what was promised, that is to report on the work done so far” external, for example http://www.postimage.org, but there are many other similar ones.

                  but there are many other similar ones:
                  1 – but there are many other similar ones
                  2 – but there are many other similar ones “direct link” but there are many other similar ones
                  3- but there are many other similar ones, or vice versa, but there are many other similar ones, but there are many other similar ones “img” but there are many other similar ones.

                  but there are many other similar ones, but there are many other similar ones, but there are many other similar ones, but there are many other similar ones ( but there are many other similar ones ) but there are many other similar ones.

                  :bye:

                  #9564
                  AvatarGiulio TiberinI
                  Moderator
                    • Offline

                    Hello Joseph.
                    In addition to what Massimo said, since you talked about inserting excel sheets with the results of your Foucault tests, I would add a tip for the speed of loading and displaying images, which is to reduce its IT dimension to values ​​of 200 or 300 kilo bytes, verifying however that, for example, in the images of any scanned Excel sheets, the reported data remain legible.

                    To reduce them before uploading them to the Hosting site, you can open those images for example with Windows Paint found in Windows Accessories.

                    Once the image is open, in its frame at the bottom you will find its current size and its definition in pixels of width and height.
                    At that point you can choose the voice “Resize” from the top menu. A window will open and in the percentage reduction boxes, you will need to replace the number 100 with a value that brings its size to 200kb for example, and then save as (otherwise savando you would find yourself reduced to the original photo that maybe you wanted to keep).
                    After you have saved you will see that the size of the image written at the bottom of the edge of the photo on the screen, will be reduced to the new value, which then requires that legibility check.

                    #9566
                    AvatarGiM
                    Participant
                      • Offline

                      but there are many other similar ones
                      As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from 200 mm.
                      As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from. As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from.
                      As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from.
                      As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from.
                      As previously said I try to publish the data and the graphs of the spreadsheet regarding the mirror from. The telescope was placed on a laboratory bench. 70 The telescope was placed on a laboratory bench., The telescope was placed on a laboratory bench. 20 mm (70 magnifications) The telescope was placed on a laboratory bench. 12 mm (116 magnifications).
                      The telescope was placed on a laboratory bench., The telescope was placed on a laboratory bench., The telescope was placed on a laboratory bench., The telescope was placed on a laboratory bench..
                      The telescope was placed on a laboratory bench. 4 mm (350 X) The telescope was placed on a laboratory bench., to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror, to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror.
                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror.
                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror.
                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror, to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror.
                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror

                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror 1

                      to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror 2

                      #9568
                      Massimo MarconiMassimo Marconi
                      Moderator
                        • Offline

                        apper !!! to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror, to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror “to the inaccurate alignment of the optics or if it was due to the processing limit of the mirror” mirror ! Judging by the test, the quality is excellent, Judging by the test, the quality is excellent. Judging by the test, the quality is excellent 5 or 6 zones, Judging by the test, the quality is excellent, Judging by the test, the quality is excellent, Judging by the test, the quality is excellent, Judging by the test, the quality is excellent. Judging by the test, the quality is excellent, Judging by the test, the quality is excellent, Judging by the test, the quality is excellent.

                        Judging by the test, the quality is excellent, Judging by the test, the quality is excellent… :bye:

                        #9569
                        AvatarGiM
                        Participant
                          • Offline

                          Thanks Massimo
                          Judging by the test, the quality is excellent, Judging by the test, the quality is excellent, Judging by the test, the quality is excellent. The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted.
                          The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted.
                          The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted, The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted, The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted. The only thing to point out is the fact that I started from a good sphere and with the tool perfectly adapted.
                          Ciao

                          #9571
                          AvatarGiulio TiberinI
                          Moderator
                            • Offline

                            Hello Joseph! Your mirror how wonderful!!

                            What can I say except that it is perfect! :yahoo: :yahoo:

                            Really congratulations!

                            1) You did very well to finish the polish, because it is fundamental, and is not detected by the Foucault test which compares, it only analyzes the trend of the curvature of the mirror in question in comparison with the theoretical parabola taken as a reference.
                            And the number one problem for newbies is to reach the good dish when the mirror is not yet perfectly polished. But a good dish on a non-glossy mirror precludes all optical characteristics making it unusable, because with the enlargements the image gradually becomes grainy dividing itself into that cloud of dots of the “Grey” represented by the forgotten craters.
                            I know something about it because I bought mine 300 by a Neapolitan amateur who had made the good dish with the mirror still gray from the amount of craters still present at that time. Mirror that I then finished polishing and parabolized (but reaching a much lower lambda than you have achieved).

                            1) From the green background graph of your Foucault calculation sheet I see that the maximum peak / valley error of your parabola is only 42 nanometers high.. And in fact they are the ones who being very minor gods 68,75 nanometers leading to the minimum wage of the famous lambda / 4, you find yourself with a stratospheric lambda / 15 and broken.

                            Recalling that since the findings of the Foucault test are a little subjective, the only solution to make them truly valid and objective is the one you have rightly applied in averaging your measurements.

                            2) I see from the graph with an orange background that Couder's criterion is fully satisfied, and therefore all 4 areas of your mirror converge their reflection within the diffraction notch of your instrument which has a diameter of 9.8 microns at a distance of 1409mm from the mirror. And therefore the diffraction notch of the stars that you will see will be much more punctiform than that of any commercial instrument…but also artisanal!!!

                            This fact (you will realize it) it means that the smallest details of the high-magnification observation will appear sharp and almost in relief. The demonstration is usually done by observing the red spot on Jupiter and even better by observing the transit of one of its moons on its surface., with the view not only of the easy “black dot” of its shadow, but also of the moon itself, despite the diameter of the mirror not very large.

                            You better not risk any more corrections and aluminate the mirror by sending it to Zaot or Zen (because I do not know if there is someone in your area who stores metals under vacuum).

                            An interesting observation only and purely “academic” I'd do it about your area 4 than in the graph with a green background, being facing downwards it might seem a very lightly riveted edge….And that indeed it is…But that the orange graph actually shows sideways reflection, but only of the (100-62%)= 38% and therefore at that focal distance always still well within the tolerance of the Couder criterion).
                            However, if you look closely at the graph with a blue background (that of the still removable glass that takes the data from the boxes of the same background color), we see that they are the zones 2 e 3 which are tall respectively (15.7-4.2)=11.5 e (18.1-4.2)= 13.9 nanometers, while the area 4 it is aligned with the progression of the parabola determined by the zone 1. (…Power of the Foucault test !!)

                            Finally, the yellow background graph of “trumpet of tolerances” confirms a splendid almost straight line!! (Whereas perfection would be represented by a straight line in the center of the trumpet!)

                            in conclusion…Still VERY CONGRATULATION!!

                            Keep us informed!!

                            And if you allow me (as a member of an Alpine choir) a quote “special”, as the hymn of the Glorious Sassari Brigade says I would tell you “There are Demons! Forward Even strength!
                            ;-) hello Giulio

                            #9575
                            AvatarGiM
                            Participant
                              • Offline

                              hello Giulio
                              I do not hide that your compliments and those of Massimo make me extremely happy and after an infinite number of hours spent trying and trying again just to be able to get a decent sphere now all this fills me with pride. I do not hide that your compliments and those of Massimo make me extremely happy and after an infinite number of hours spent trying and trying again just to be able to get a decent sphere now all this fills me with pride. I do not hide that your compliments and those of Massimo make me extremely happy and after an infinite number of hours spent trying and trying again just to be able to get a decent sphere now all this fills me with pride.
                              I do not hide that your compliments and those of Massimo make me extremely happy and after an infinite number of hours spent trying and trying again just to be able to get a decent sphere now all this fills me with pride, we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise. we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise. we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise. we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise, we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise, we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise. we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise. we wait to ring the bells because as you rightly said the Foucault test is quite subjective and it will be better to carry out other tests including a star test before defining it as wonderful or otherwise 19 mm. Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one. Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one. Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one. Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one. Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one, Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one, Well it happened the bit as it dug and widened slightly so we have that the lower face is very little bigger than the upper one.
                              Hi everyone

                              #9576
                              AvatarBartolomei Mirco
                              Moderator
                                • Offline

                                Hello Joseph, a big welcome from my… :bye:
                                I can only join me too, I can only join me too, I can only join me too… :yahoo:

                                Do not worry, I can only join me too, I can only join me too. I can only join me too, I can only join me too. I can only join me too, I can only join me too, I can only join me too 1-2 I can only join me too, I can only join me too. :good:

                                Ah, by the way, I can only join me too? I can only join me too? I can only join me too, I can only join me too…

                                thank you,
                                I can only join me too… :bye:

                                #9577
                                AvatarGiulio TiberinI
                                Moderator
                                  • Offline

                                  Hello Joseph.
                                  I recommend that you have your wife read our thoughts on your work, so that I can forgive :heart: your disappearances in the garage.

                                  As for the aluminature of the mirror, the companies in the North that I know and that do this service, you can call to get a quote, are two:
                                  the company ZAOT S.r.l.. Thin film coatings, of 20010 Vittuone (ME);
                                  and the Company
                                  OPTICAL BUILDINGS ZEN Di Venezia San Polo n.1871 / A

                                  From which sites, or by contacting by phone I bring you quotes and satisfaction to your doubts on the question relating to the fixing of the slightly truncated conical shape of your mirror.

                                  Both practice aluminizing, on request protected by a SiO2 layer.
                                  I know that with an increase, one of the two companies produces the multilayer aluminization with improved reflectance (“Enhanced”) which has a reflectivity greater than a 5% compared to the single layer (which would be like having a mirror with a larger diameter of this value), but which is also more resistant and for the same diameter mirror costs more.

                                  But it may certainly be that there are other companies of optical aluminization that I do not know and equally valid.

                                  Regarding the shipment of the "mistreatment-proof transport by various couriers" mirror, I would like to suggest that you pack the mirror by building and inserting it face down, inside a plywood box as specially designed on a professional level, (and as I always have), to be inserted in turn inside a larger cardboard box also containing polystyrene protections on all 6 sides.
                                  That plywood box suitable for blocking your mirror inside must be built "to measure" as can be seen in the three-minute video of the following link (which start by dragging the slider at playback time towards the end of the movie, at the level of 1 now 53′ 27”)

                                  Tutorial video: Construction of a parabolic mirror 200F6

                                  Ciao – Giulio

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