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in this way, however, ', It goes with the tool center on the edge, instead adrebbe not touched.
the areas to be excavated, in this case, They should be reached from the inside, Doing so could increase the edge retorted.
the technique you described could go in my opinion, provided to always keep the tool inside the mirror and to generate in case the pressure on the part of the tool towards the borbo.Please try https://postimages.org/ , Once loaded the image copy and paste the link “direct link”
hello Fabio, e’ very interesting object in the correction, at first glance it may seem simple but it is not '. I would keep some aspects in mind:
1- the figure has a very regular trend, a sub-diameter, which only works on the affected area, however, is likely to alter the regularity of the figure. ( which then should be smoothed again ) Since the sub and’ I also would try with fairly extensive racing to w ( more’ large on the center and denser on the outskirts, in such a way as to connect the entire surface to form new.
2- anyhow, as suggested by Giulio, you should take “confidence” with the tool, see how the surface responds to actions exercised, because the variables involved are many and much depends on the way of working of the operator, more than with the tool at full diameter.
said this, I follow with interest your job !
p.s.: to insert images in post:
1- copy the link to the image
2- to select “img” from the tag bar just above the text field.
3- paste the link and give ok.hello Frank, Happy new Year to you too!
Wow what job! sincere congratulations, a refined and cured realization in all respects, from design to construction, with a complete and interesting description of all the working phases.
A valuable work, certainly far beyond the simple ability lover (at least my), Here mechanical work must know them well, such as’ rightly…
p.s. however, the “Frank’s knobs” They are better than those of Bob !
Hello Marco, welcome ! Is’ a pleasure to have you here, we hope to be able to help you with this new adventure of yours.
I see that you have clear ideas about the goals you want to achieve and this is definitely a good start !
Therefore a “good luck” and I will follow with interest what you want to share on our pages.Per i test, I think it is quite a broad discourse, anyone and anyone can do well, it depends on many factors, including the ability and aptitude of the operator with a certain test, in a way it is a bit’ how to ask which software is better for image processing.
Perhaps the best thing is the use of multiple methods for the same surface to be checked, it being understood that, from what I've seen so far, the only one that “never lies” is the star test.
For those like you who have the opportunity to have an instrument with a reliable structure available even before having finished the optics, the star test is certainly to be taken into consideration as a verification of the results obtained with other methods.Hello Charles and welcome again ! I think the 20 cm is the diameter “perfect mirror” to start, not because it is easier, but because everything is faster. This does not mean that you end up first, but that at the same time you have the chance to miss more and more correct. therefore, Consequently, you learn more.
hello Luigi, I would say that if the announcement of sale of a blank is already in breach of Regulation, more so it would be a buying group ( presumably for a supply of several blank )which would open in fact a full-blown business “sponsored” on our pages.
This would set a precedent that would legitimize subsequent requests from anyone planning to sell any product, mirrors, glasses or abrasives which are, individually or in series.Coming instead to content, I would say that it is not prudent to evaluate the purchase of borosilicate glass for optical use only with the assumption of “price competitive”, for different reasons:
1- the production process of borosilicate glass must be made up of several phases before being able to dispose of the finished product suitable to our use. Even taking the Supremax directly from Schott ( the top of borosilicate glass for optical use professional quality), would still “annealed” to eliminate any internal tensions due to the rapid cooling of the typical process “rolled” in which the molten glass plates are subjected, hence the final price does not properly “cheap” for SUPREMAX.
2-Addressing other companies around the world ( lately it seems that the Chinese go crazy for the production of borosilicate ) the price of these products is directly proportional to the quality of the material is that of production, then in general a cheaper product is not said that it is a “deal”.
3-often the glass is subjected to a tempering process that increases the resistance but prevents subsequent processing. Beware that sometimes is not even explicitly stated in the data sheets, that it is glass “tempered”
4 – the stated thicknesses may not be related to the same castings, but could be laminated glasses, obtained with overlapping plates and bonded with thermoplastic polymers and materials to increase strength and make them compatible with the safety regulations for structural works, Constructions, etc…
Be careful because you are likely to have in my hands a blank unusable as a parabolic mirror, but very effective as a bullet-proof glass. the previous message was removed because our policy does not allow the inclusion of commercial ads or sales in general for products relating to the activities and topics of the blog / forum.
therefore, as well as to renew the invitation to all participants to Grattavetro to take vision of our Regulation, we are forced to remove any action that is inconsistent with our guidelines on publishing content.
This choice stems from the fact that we are not structured to ensure the accuracy of listings and proper negotiation seller / buyer and would not be able to protect neither the one nor the other.
There are very valid sites that deal with the astronomical material purchase plus have a public directly interested in such advertisements.Ciao Alessandro e benvenuto nel “covo” ! speriamo di poterti essere d’aiuto, un rc 300 é una bella bestiola, é un peccato lasciarla nel baule, luogo notoriamente più indicato per i rifrattori…
Purtroppo non ho modo di avere accesso ad un test di focault o di Ronchi, questo mi frena ma se trovo qualcosa in rete (in Italian) provo a costruire io qualcosa.
Se la ricerca in rete non dovesse dare i frutti sperati, puoi sempre cercare qui sul Grattavetro
…although I would like to work myself a mirror but I really don't know where to start…
Well, you are in the right place !
Yes Andrew, it is possible to parabolize an f9 and it is certainly a fairly fast operation, at least in terms of workmanship.
The difficulty is in fact in the precision and reliability of the measurements given the slight deviation of the parabola from the relative sphere for such a long focal length.In any case the mirror must be parabolic, with the spherical mirror ( even if f9 ) on wide fields at low magnifications one might have the sensation of an enjoyable image, but in high resolution all the details would be lost as the focal point would not be determinable. Spherical aberration on the optical axis, albeit of small value in an f9, it is still present and makes the stellar size in the focal plane larger than the Airy disk, effectively nullifying the achievement of the resolving power of the optics even in perfect seeing conditions.
