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hello Giulio,
you have a very similar philosophy to some of my colleagues. My philosophy is a little’ different: we say it is pretty easy for a technician “not the branch” like me, you find yourself thinking things already done. And the synthesis of mechanisms is something that brings, Topics covered in a long time, find themselves with almost everything already done. I say almost, because since I work for the developer of prototypes, if it was really all-all done the same technology I would have been fired
Anyway thank you very much for bringing your field of experience on this blog. Moreover, as you wrote, design without deadlines is really fun!
I will keep in mind the advice to put in abutment on one side of the tooth profiles of the telescope by weight. I was concerned as a solution because I have read of people who have found themselves losing the evening due to a movement of the pipe, once it exceeded a certain angle. For that alone probably insist on good old mechanism that I described.Thanks Julius and Mirco, it is important to have feedback especially in the preliminary study phase.
Anyway, Giulio, I do not know whether to be happy to have thought something good and tested or be depressed “not original”. In the picture I've shot I saw in REALIZED essentially the sketches of my last 2 months. And me, I had only seen the classic fork mount, I thought I had invented “a new cool”. Oh well.
In reality, what I am designing has important differences from what I've seen.
First of all, mechanics. I will not use pulleys and friction wheels. In the field of machine tool was used, until recently, a mechanism to 4 gears for each speed reduction in which a spring created the “zero backlash” between the teeth. The modern machine tools using 2 engines and electronics. I intend to make the gearbox backlash making a reducer 1/86164 zero backlash and associating an engine that goes to 60 rpm. The last wheel has a stretch of gear (imagine a curved rack) allowing a few hours tracking. The engine I turn it on just before he “found the target” with 2 idle movements from block. In two idle movements there will be other 2 backlash mechanisms, micrometrici, in the future motorized micro adjustments if I have time to play with electronics, I try to always have that pointed to perfection.
But I do not have the space to keep this thing whipped. So I'll have to do the whole thing as a removable transformer to be put away. It will have a type configuration trolley for transporting. Knobs will block the macro components in a configuration, and the other.
A normally use expensive cad 3d work that I can never afford to be private, especially avoiding too risky piracy. But even so my PC could never run them as you have
So for the 3D CAD I will assess what I find. I know a non-parametric CAD 3D for free, but not in mechanical parametric stands for insults to our lord. I do not remember what “good” He was managing assemblies. Another 3D CAD parametric, free, ma “creepy”. Meanwhile, I'll try to see what I recommended Giulio.Thank you so much guys! You're opening up a world. I will start to build me a classic Newton. Now I have enough elements to understand why no one had done it before. Massimo's speech is clear to me. Really I had not thought. At this point, given that a diameter telescope at least 300 I want to build, I think that I need to focus on two other points:
1) beautiful the link you shot me, Mirco, but you'd know I recommend one or more reference books argue that everything in a certain order by “base”? As a cultural basis I did mechanical engineering and I have no problems with English and French. In other languages they are not at a sufficient level for technical studies.
2) I am reading other posts I started to look at all the most popular printers in the 3D market. I am strongly fought: for little money (circa 450 euro) I found a pretty good printer (+-0.08 mm) but it prints only PLA or there are other printers that are also ABS but have lower tolerances (+-0.2 mm or worse). The PLA on paper is not bad at all, in that it has a young modulus 1,5 times higher than the ABS. Also loads for this application “almost static”, then it worries me just the tendency to brittle fracture. I'm more concerned that I will “Dough-Boy” the mechanisms. Other materials are very interesting (example PLA or carbon loaded nylon) , but it passes at least 1500 € Printer. For the PLA simple, it seems that just be careful not to leave it in the car. But you, in that printed material?I hope functions,I'm trying to link the image using PostImage
hello Giulio,
because of the explanation for the images.It's exactly as you described. The image shows a circular mirror plane that increases the obstruction of the primary, and finally the postponement on the tertiary elliptical.
As soon as you can around the picture
hello Giulio,
I saw some of your project forum, congratulations.I have some difficulty in attaching images. If you explain to me how to attach the photos I take a picture of the sketch on paper “concept” what did I do. The first expense that I will be that of a more serious pc where to CAD, although it will never be like what I have to work
I say immediately that in light of what I read in other posts that sketch should be improved (I have not taken account of the diameter of the eyepiece, I am only released from the tube diameter 200 mm as a parameter of “guide” because we own the focuser, leaving a second moment the details).
For a feasibility study that was fine.The fact that what we build will be for astrophotography implies a geometry that I have not yet defined (despite the dozens of sketches) because I have a lot of ambitious ideas about stiffness, “disassembly” and weight so I'll have to work a lot. One idea is even no real tube, with false cover for the light. But I still have to work several months before moving to CAD, especially if in the end I give up to the compactness of the mounted telescope because they give up to do so 3 mirrors.
Better know how certain things before you fail done shopping. I gained this day the fatal truth about flat mirrors. The reason why I wanted to make a compact Newton was not so much to lower the observation point (it's still been an interesting discovery, I not know them) how much to increase the overall structural stiffness and bulk.
Back in Training!
I have a few other options:
1) settle for a 300 mm f4 f5 about, which greatly reduces both the weight and the size (that the light
). Maybe just because of half the weight becomes beautiful hilarious.
2) sacrificing the small size of the mounted telescope and design a “very normal” 400 mm f4,5 (I can find “cheap”) removableI had already discarded for the manufacturing difficulties (First I should make me the bones) or the cost (shopping) the others 2 options:
3) learn how to build a Cassegrain – I have never seen large diameters: which suggests, especially for the corrector plate which closes the
4) learn how to build big mirrors very short focal length. It is obvious that this can be complex
Thanks for the explanation, now I come to throw down other ideas, comparing the 1) and 2)
