development of sheet metal

[DrBarde]

Good morning.

Unfortunately I have not found specific discussions about the subject, so I open a new one.

assumption:
in the company for which I work, when making the metal sheets, usually from 4mm, the total length of the sheet in the inner part is considered as development, as an example of the following made in 2dproblem
we are trying to reproduce the same effect in inventor, since the design has moved, rightly, to 3d. but every time the sheet is shorter than 3/5mm, and we can not understand how to solve the problem. we don't know what values to intervene, or if we miss the commands. we tried with flanges, hoppers, profiling but the result does not change on the flat model.

 

[Peppe]

give an eye to this "old" debate

 

[Davimont]

but with internal development did the measures return? ?
I have always calculated the development on the half thickness and have always come right.
for the classic round tubes I calculated the calculator development and for more complex developments I set the k on the cad to 0.5.
on the inner surface are short.

 

[DrBarde]

Yes, with internal development, measures have returned for about 40/50 years.
However from what I understood the only way is the k factor, thank you very much to all.

 

[biz]

depends on the punches and the matrices that are used.
all theoretically refers to factor k.
so if you have external suppliers developments if they should do them, while if you work internally you build your table with the k factors and implement it in the cad.

 

[DrBarde]

depends on the punches and the matrices that are used.
all theoretically refers to factor k.
so if you have external suppliers developments if they should do them, while if you work internally you build your table with the k factors and implement it in the cad.

is what has been done in the past years, but some machines had not been implemented since they were still doing on the 2d by hand. now that we are going through everything to 3d, we are doing internal evaluations on how it is better to manage the situation of the machinery of our own property. factor k is one of those values that we do not give, to the designer, the possibility to change. Therefore we opted for a solution to create models for the processing of our machinery, since development is never given to the external supplier but only to the internal one, of which we are obviously the technical office.

 

[Zac69]

if you use a sweep of a tangent circle outside the line that the circle must follow? the line is external and you have the size, the sheet goes behind it.

 

[PIETRO2002]

depends on the punches and the matrices that are used.
all theoretically refers to factor k.
so if you have external suppliers developments if they should do them, while if you work internally you build your table with the k factors and implement it in the cad.

There are no punches and matrices in the grilling, the sheet is curved through rollers.

 

[PIETRO2002]

in the development is normally considered the factor k that changes according to the material, under the conditions in which the material is located and also with respect to the direction of rolling of the sheet.
on small thicknesses you can also use the average diameter... problems arise when large thicknesses fall (50 or 100 mm) where there is no possibility of making mistakes, in this case using the inner diameter to calculate development would be a "suicide".

 

[MassiVonWeizen]

the only way to define the k factor is to test the various materials and thicknesses.
A well-known measuring sheet is cut and the final measurements are detected, in the cad you draw the particular calandrate with the measurements detected and then adjust the k factor until the development corresponds to the size of the cut sheet.

 

[biz]

There are no punches and matrices in the grilling, the sheet is curved through rollers.

I know, I thought it was a folded sheet.
Excuse me.

for the displacement, with regard to not too large thicknesses, we say up to 10mm, it is enough to consider as a neutral surface that passes through the center of the thickness. precision is the order of a few tenths.

the concept does not change. always of factor k we talk.