MarcoBi
Guest
I did (shorts) some design lamps. Turning in sheet was the technology used for all reflective caps (1/2 ball) and was much cheaper than molding. a form (wood or metal) and a "painting pin".:finger:
flaviobrio88
Guest
Sorry guys, but it would not be better to call it "inviluppo" this procedure, it seems to me to understand from the videos that already starts from a form developed to get to a shape 1/2 spherical and not vice versa.
paolino
Guest
mm, I think the problem is: what is the definition of developing surface? I try.
in geometry a surface is said to be developed can be locally unrolled on a floorif you consider this definition, a semisphere is not developable, in fact it cannot be unrolled On a floor. However, with a sheet you can get a semisphere with operations (cylindrical tones, funnel, hammer, whatever you want!) that are not limited to Rolling the sheet, but they exploit the malleability of the material that allows to remove / approach two points of the surface without that between them we create fractures or wrinkles.
back to the initial question: if the purpose of neverste is to make a paper sticker, unfortunately, being the paper not as malleable as the sheet, anything will get when it will apply to its undevelopable surface this will make some wrinkles or it will tear itself somewhere. . .
enri
Guest
I think there are cases where the gap between the curved sup, and the same flattened is so minimal that no appreciable defects occur. This especially with the ball strips, in fact there is a rhino plugin created to make constructions with double curvature surfaces, and among other things there is precisely the conversion of complex surfaces in developing strips that still contribute to the realization of the same. then we all saw at least once a label on a container not perfectly cylindrical, or even almost spherical, like many bottles.
Fulvio Romano
Guest
In fact, here it seems to me that it still confuses "undevelopable surfaces" with "surfaces that can not be produced from sheet metal".
The two things are different. with plasticine I can do what I want, and metals, within certain parameters, look a lot like plastiline.
However, those who say stuff like "leave math, in reality things are different" are people who know nothing about mathematics. I would like not to be contradicted on this statement please. . .
math is a invented tool to describe the world, if reality is different from mathematics, it simply means that the tool was used badly and did not manage to describe what you wanted to describe.
In fact, the "non-developable" surfaces are developed by specific software, which certainly not "proof", but "calculate".
Fulvio Romano
Guest
fantastic the guy from the first video...
I hope he's a craftsman. ..without gloves, helmet, glasses, without physical protection, without safety pedals.
I wouldn't wonder if the lighting was at the neon...
At least if it is an artisan, the day that loses an arm can only take it with itself! If he's an employee, there's someone who needs a few years of jail.. .
maxopus
Guest
In fact I have never confused the two things (the mathematical development, with the development cad finalized to certain productions).
I know mathematics, because I taught it to engineering students, and I don't understand why the discussion took this direction.
the initial question was inherent in the development of a plastic piece and dealing with stuff that in 99% of cases is made in thermoforming ... development is done.
in all this, that there is the mathematical development of a sphere since it is clear to most that any geometric entity with double curvature is not mathematically developable in the plane?? ?
I know mathematics, because I taught it to engineering students, and I don't understand why the discussion took this direction.
the initial question was inherent in the development of a plastic piece and dealing with stuff that in 99% of cases is made in thermoforming ... development is done.
in all this, that there is the mathematical development of a sphere since it is clear to most that any geometric entity with double curvature is not mathematically developable in the plane?? ?
flaviobrio88
Guest
Excuse me.
First of all I wanted to clarify a point, personally I just try to understand things that I do not know, and if there are doubts I try to try to understand by asking for clarification, we are big enough and I believe that each of us his experiences has already made them.
If then there are unfamiliar technologies, I think it is lawful to deepen, said this I try to understand better what I saw from the video.
It seems to me that you start directly from a flat figure and not vice versa as the problem mentioned, then get to a semi-spherical figure, and that the lathe doing this go to eliminate the curls anything that would not happen trying to wrap a card on a sphere.
So for my curiosity I ask you if the procedure used in the videos is the above.
Thank you.
flap
First of all I wanted to clarify a point, personally I just try to understand things that I do not know, and if there are doubts I try to try to understand by asking for clarification, we are big enough and I believe that each of us his experiences has already made them.
If then there are unfamiliar technologies, I think it is lawful to deepen, said this I try to understand better what I saw from the video.
It seems to me that you start directly from a flat figure and not vice versa as the problem mentioned, then get to a semi-spherical figure, and that the lathe doing this go to eliminate the curls anything that would not happen trying to wrap a card on a sphere.
So for my curiosity I ask you if the procedure used in the videos is the above.
Thank you.
flap