- This topic has 22 replies, 4 voices, and was last updated 7 years, 10 months ago by
.
-
Posts
-
Hi everyone!
I have recently a self-made frame that leads 150 kg in a fixed position in the garden and I am therefore interested in the processing of optics to give it an adequate telescope in the near future…! So I would like to start with the processing of a smaller optic in order to learn but, browsing on this (rich) site are unable to identify the exact sequence of types of pass! Could someone point me to a list in order “chronological” Passes to be made, starting from a blank plane up to the finished optics? Thank you!
Hello Marco, welcome to the Grattavetro ...
Then, as you can read in the various articles that you will find here:
https://www.grattavetro.it/category/lavorazione-specchi/tecniche/
the techniques for processing an optics for the construction of a primary mirror are various, and each has a specific purpose.To briefly answer your question I can tell you that the sequence to be used is the following:
1) it starts with the "cordata":
That allows you to quickly dig the mirror and reach a good digging depth quickly, even if the shape that is generated is not spherical. Once an excavation depth of approx 2-3 tenths of a millimeter lower than the final one, you can move on to:2) Stroke 1/3 COC:
Stroke 1/3 COC: easy easy method for the right amplitude of the past
Which is the type of pass that allows you to regularize the surface and make it become a sphere.
Once the right digging depth is reached, you can continue with the same type of pass, this time though, with cerium oxide and pitch tool, for polishing the surface.
When polishing is complete, and if the surface is beautiful spherical, you can move on to the parabolizzazione of the optics, which has the purpose of bringing the surface from spherical to parabolic. This is done with:3) Passate a W:
All the other variations of these past bases, they are used to remedy the errors that will inevitably arise during processing. But you can study these well later. For now I advise you to read carefully the articles I have suggested to you, so you can get an idea of what are the fundamental past.
P.S: obviously as we dig the mirror and we get closer to the final depth, from time to time it will be necessary to change the grain of the abrasive by gradually getting finer and finer. As soon as I find the article which suggests a sequence of abrasives to use, I point out the link, but you can also find it yourself by browsing the site.hello Mirco.
By the way Marco,
Where are you from? what tools do you have? passions? places where you usually go to observe? visualist or astrophotographer?ah ah ah, do not worry…I'm not giving you the third degree….
it's just that I like it when a new member shows up a little, so that I can get to know him better and maybe find someone else who shares my passions or maybe coming from my areas… See you soon…ciao
Thanks a lot Mirko, that's just what I needed!
In response to your curiosities, I am a mechatronic engineering student from Sandrigo (Vicenza), i have a newton 250/1200 BD SkyWatcher and an 80ED SkyWatcher gold series that I usually use on an nEq6 with an Atik 314l +, plus the self-made frame I mentioned earlier (this link is from a site “secret” I'm working on where you find some details, I have yet to publish it so water in the mouth! if you want to take a look look at the February issue 2016 again orion) then… I usually watch from my garden where despite being close to the center of Sandrigo, Luckily, it also arrives at 5,5 with the naked eye in the best evenings. And finally… Mainly astrophotography! your? (Ah, congratulations to all those who contribute to this site, it is full of information!)Hi Marco and welcome to the Grattavetro ! good, I see that besides being “neighbors” with Mirco, you also speak the same language ( that of Engineers )
Thanks a lot maximum! Ah, good, I don't know where Mirko is from but if we are close neighbors it could be useful!
While we're there… Could you tell me if by chance there is some glassworks in the Vicenza area where I could find the blanks? I have already sent a couple of emails but have not received any reply… I will introduce myself there in person…!Hello Marco, see that I was right to ask…We are from the same area, and in addition we have already met, at the astronomical observatory of Nove, after the lecture by Roberto Ragazzoni…Where did you show me your work in progress of the project on’ SQM, by the way how it went on? you did tests?
In the end I also bought myself a 3D printer, even if Cartesian and not delta…P.S: I am from Pozzoleone, then a 10 min from your home…
hahaha but look at you! coincidence…! regarding l’ SQM seems to be all right, I did some tests comparing it with that of’ observatory of nine and has a very good answer, account to arrive at an error of 0,05 magnitudes which in my opinion for a self-built SQM is not bad…! (in the site of the link that I put you find a little something about that). Returning to the processing of optics, since I seem to understand that you have a lot of experience behind you, if you don't mind I'll take advantage of your knowledge…
I have been touring this site for weeks but it is literally a world! and obviously I don't have too clear ideas on what to do… if you don't mind I would like to find us soon as soon as you have time, I have many questions! See you soon! Thanks again for the warm welcome! It's nice to see how despite this being a very niche topic (we are already few amateurs, I dare not imagine self-made amateur astronomers…!) You can all be so active and enthusiastic!
Hello Marco,
Yes, certainly very gladly, although for me unfortunately, from tonight, Christmas holidays end…so between work, football and various commitments I won't have much free time from tomorrow…we will agree anyway…
In the meantime, continue to ask any questions you want here in the forum, and you will see that you will find several prepared people, who will be able to answer all your doubts…
See you soon…ciao of course, for me too it will soon be difficult to find the time since I am under examination… as soon as you have time let me know so I try to organize myself! maybe we'll talk over the phone which is a little more comfortable! my number is 349——-
and not to spite someone but not having the faintest idea what to do I would prefer to talk about it in person rather than in the forum, at least until I have a’ idea a little more precise on the various stages of processing (also because I am in no hurry to start given the short exams…) See you soon!little OT :
Hello Marco, it is never advisable to post your phone number in an online forum / blog, as every single word we write is effectively indexed by the search engines in a very short time. This means that it is very easy that this data then, combined with those already present in other posts, related to name and possible address, will be used by anyone who comes into possession of it for the most varied reasons, lawful and not, from advertising to identity theft, in particular the latter is a problem, often underestimated, constantly growing on the web and towards which we must pay close attention.
therefore, unless you have some interest in making your data public, my advice is not to write personal information in the forum, better to use private messaging or traditional e-mail.
Sorry Marco , but I feel compelled to highlight these aspects, so that anyone who writes on the Grattavetro is more aware and protected from some potential network risks.
- You must be logged in to reply to this topic.