factor k development sheet.

[Ste80vi]

look, I can provide an indirect experience with regard to the drawings that come to me here in the company from customers I think have the flower of the three-dimensional since the sheet is their daily bread: flat view is provided by their own 3d but elegantly solve the problem with a nice squared citadel note: "indicative development". as you say correctly, a technical study must not go to the point of pointing out a profile that has the claim to provide to those who have to carry out the work materially the proper development of the artifact. In my opinion it is impossible! instead a technical study of a company should analyze a design and prepare the developments to be sent to cut, in that case it will no longer be a phase of design that will serve, but a phase of planning as it will go to analyze a series of factors, like precisely the type of bending tools, the real bending rays that follow it (going to compensate therefore those areas that must then be well coupled for the subsequent operations own welding,
In my opinion, to provide a development that presents the only theoretical internal surface with r0 rays, or that instead provides a surface relative to what would arise with a k equal to 0,5 (i.e., with neutra fiber in the center of the thickness) little changes : however, those who must realize the piece must be resumed in hand, shortening or elongating the zones in correspondence of the bendings. Then, I have seen of all colors: I have seen companies (in fact, aziendone) start with the cutting of a prototype adopting the development of the design of your client (to understand the one with the written "indicative development" to see where you go to parare! I have seen the delivery of pieces to be soldered in tig with thickness 1 for which even a coupling summary highlighted huge gaps. An example? the discharge in correspondence of the folds, that is the circumference that is used to make in the area of the edges to ensure that the compressed material of the bending does not go to "urtare" with the adjacent bending... if you consider the bending radius generated by the tools, that type of unloading is useless. complicates and extends only welding operations, aggravating unnecessary costs. Therefore, to say all about it, the drawing of a piece to start production from my point of view also means having to "review" a whole series of details to which - more than rightly - the designer does not think, but that a technical office that has the task of "to eat" laser and bending machines has the obligation to do to make quality pieces with more efficient times possible. and it is not at all discounted!
Back to your problem, if I have a little time I will try to make 4 accounts but I am very doubtful to be able to find a k that allows you to get to your result... you will get semmai (perhaps) one worth for each radius and thickness, but not for every bending angle......
a greeting and good work to all!

 

[Marco74]

It seems that I will go to work in a workshop where I will take care of cutting and bending sheets.
I have searched on the forum and read so many things.
Now I would like to ask a practical question, just to begin to understand the matter well. . .
suppose to draw a piece to l 50x50 from 2 mm and internal radius 2mm. then I cut it to the laser and piego in the workshop. I mix the piece and see that the l is shorter than 0.1 mm on each side.
how do I understand the right value of the k factor to set up on sw to achieve correct development?
Thank you.

Since you know the real value you have to adapt the k factor until you get the desired result, so every time you make a piece of that thickness with that fold radius using the k factor you found you always get the same result. Keep in mind that you have a different result when changing a quarry or knife, so a new factor k. Welcome to the world of sheet metal. Hi.

 

[xxfast]

Since you know the real value you have to adapt the k factor until you get the desired result, so every time you make a piece of that thickness with that fold radius using the k factor you found you always get the same result. Keep in mind that you have a different result when changing a quarry or knife, so a new factor k. Welcome to the world of sheet metal. Hi.

Thank you 1000 rotten.
Fortunately from then to today no longer had problems and with some experience on the field and the collaboration of the operators, in the workshop, everything is smooth yarn.
Of course you do.
what I have noticed going around for some workshops is that not everyone gets excited to draw the sheet metal parts as they should be, but many just do the various folds without worrying about the result of development, so much they think in the workshop to make the accounts square.
or they just don't know how to do it and don't care.
then of course, every place where you go is a reality to yourself and you have to adjust accordingly.

 

[Marco74]

what I have noticed going around for some workshops is that not everyone gets excited to draw the sheet metal parts as they should be, but many just do the various folds without worrying about the result of development, so much they think in the workshop to make the accounts square.
or they just don't know how to do it and don't care.

We say that there are many who work with quite gross tolerances, but obviously to their customers does not matter much about precision. Unfortunately where I work I have customers who ask us about particular bent tolerance of 1o2/10. with certain thicknesses you can respect them, but when you start bending thicknesses of 4-5 mm up also come to dance other factors like lamination, cut piece outside the sheet rather than at the center. these factors make the result not always equal, both by size and fold angle obtained, so with corrections
continuous by the bending machine. then what we learned at our expense by analyzing a sheet of sheet with certificate for s355j0....result of analysis s275jr. therefore also this affects both in fold and in welding. I hope I've been quite exhaustive and helpful.
Hi.

 

[ciao_]

Good morning to all,
Excuse me if I introduce myself to such a hostical discussion but since I started an internship I have a big problem with the plates.
using solidworks the parameters I have to set when I fold a sheet are the fold radius and the k factor, while when the operator folds the sheet metal wants to know only the internal size and size of the matrix to use. Does anyone know a way to determine, know the type of matrix and sheet material, the internal fold radius and the k factor to give to solidworks??
Thank you very much to all for what you already do and for what you will do
p.s. I tried to use the mike table where there were all the information but unfortunately there were no matrices that use the company. Does anyone have any more?

 

[Mike1967]

Good morning to all,
Excuse me if I introduce myself to such a hostical discussion but since I started an internship I have a big problem with the plates.
using solidworks the parameters I have to set when I fold a sheet are the fold radius and the k factor, while when the operator folds the sheet metal wants to know only the internal size and size of the matrix to use. Does anyone know a way to determine, know the type of matrix and sheet material, the internal fold radius and the k factor to give to solidworks??
Thank you very much to all for what you already do and for what you will do
p.s. I tried to use the mike table where there were all the information but unfortunately there were no matrices that use the company. Does anyone have any more?

Bye.
I attach a table (it is quite updated even if it is not the last version, the official one I have in the office) where
You can see the widths of the folded quarries.
to get to this we made auditions with various materials and thicknesses, so with our bending machine
The folds are consistent.
Bye, good year.

 

[ciao_]

Hi.
thank you very much for the help good year also to you and thank you really

 

[sbarbo04]

thanks 1000 mike 1967 for your very useful table.

If I have correctly understood your table read this way?

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
all examples are for fe360

example development calculation (external measurements of a 90° folded l)

30x30 sp2 with v from 12 (matrix 20.245) comes 28+28+0,675=56,675 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.212

50x50 sp3 with v from 12 (matrix 20.245) is 47+47+1,3=95,3 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.28

50x50 sp3 with v from 16 (matrix 20.332) is 47+47+1,2=95,2 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.26

50x50 sp3 with v from 25 (matrix 20.334) is 47+47+0.6=94,6 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.13
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

thanks again and good 2015
steak
Potatoes

 

[Mike1967]

thanks 1000 mike 1967 for your very useful table.

If I have correctly understood your table read this way?

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
all examples are for fe360

example development calculation (external measurements of a 90° folded l)

30x30 sp2 with v from 12 (matrix 20.245) comes 28+28+0,675=56,675 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.212

50x50 sp3 with v from 12 (matrix 20.245) is 47+47+1,3=95,3 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.28

50x50 sp3 with v from 16 (matrix 20.332) is 47+47+1,2=95,2 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.26

50x50 sp3 with v from 25 (matrix 20.334) is 47+47+0.6=94,6 mm
the same development calculations with sw if you put r inside fold 0.001 mm and k=0.13
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

thanks again and good 2015
steak
Potatoes

exactly.
in case you want to draw the sheets with the "realistic" fold radius (which I use in 99% of the design) you will only use the fk of the Red column.
as a "realistic" radius I did nothing but insert a radius (inside) that is equal to the thickness of sheet that we will draw.
I hope I helped you.
Hi.

 

[sbarbo04]

another curiosity:
Looking at the column "theoretical int. radius" I see that in 70% of the cases this radius has the value 0.001 while for the matrices with v from 40 and v from 50 the value goes from 4 to 8 mm.

for example I tried:

50x50 sp4 with v from 40 (matrix 20.211) comes 46+46+0,6=92,6 mm
the same development calculations with sw if you put r inside fold 4 mm and k=0.37

which are the parameters shown in the table, but in this case are the real internal radius (4mm) and the real k (0.37)

How come you don't always use int. theoretical radius 0.001?

Thank you
Hi.

I made an excel sheet that allows you to calculate the k factor, if it can be useful you find it attached

steak
View attachment calcolo K.zip

 

[Mike1967]

another curiosity:
Looking at the column "theoretical int. radius" I see that in 70% of the cases this radius has the value 0.001 while for the matrices with v from 40 and v from 50 the value goes from 4 to 8 mm.

for example I tried:

50x50 sp4 with v from 40 (matrix 20.211) comes 46+46+0,6=92,6 mm
the same development calculations with sw if you put r inside fold 4 mm and k=0.37

which are the parameters shown in the table, but in this case are the real internal radius (4mm) and the real k (0.37)

How come you don't always use int. theoretical radius 0.001?

Thank you
Hi.

I made an excel sheet that allows you to calculate the k factor, if it can be useful you find it attached

steak
View attachment 39234

0.001 value (fittitium, add) is used to override problems of automatic grooves that sometimes
solidworks does not digest.
I have not understood your table well: Why should I put the right development?
It's a spreadsheet. He has to do it.

 

[sbarbo04]

with the excel table I posted you can do 2 things:

1) calculate the k factor after a test (the first option)

2) calculate the k factor by knowing the withdrawal (which I draw from your table) and hypothesize bend radius equal to the thickness (second option)

Hi.
steak

 

[volaff]

Hello, everyone.
would anyone also indicate theoretical references regarding the calculation of the development of a sheet?

Thank you!

 

[giova95]

hello to all boys, I read everything you wrote and shared here. I need help like that, do any of you use offline bending programs? I better explain a bending program from offline (remotely) which then must be sent directly into the machine with 3d attached and quota references already affixed. these last mentioned the references (recontri/ fingher) as you wish. I use autopol for example to always leave the x abundant compared to the final quota that should go out. Does anyone know anything about you? or if you always have to make a correction on board machine for each tool combination like the various tables you sent.
Thank you very much for those who help me.
Hi.

 

[MassiVonWeizen]

does not seem to me a specific problem of solidworks

 

[4L3.8623]

Good morning to all,
I read a bit all the thread I find many interesting things regarding the whole part of tables settings for bending. I press work in light carpentry but I never tried to optimize the workflow by going to set the various bending parameters.

working with sw in the company we use these parameters:
- thickness;
- radius
- factor k

working these 3 parameters I always put them manually. By reading this thread I found a way to create a series of tables that allow me to automate, according to the house and thickness, the values of thickness and radius.

my problem that I can't automate factor k. probably wrong in something as I set the table (see image) by banally inserting the k at the radius and fold degrees.

is there a table to be associated with what I attach as an image in order to automate the value of k or is it a request that cannot be made with sw?

Thank you very much

 

[Marco F inox]

Good morning to all,
I read a bit all the thread I find many interesting things regarding the whole part of tables settings for bending. I press work in light carpentry but I never tried to optimize the workflow by going to set the various bending parameters.

working with sw in the company we use these parameters:
- thickness;
- radius
- factor k

working these 3 parameters I always put them manually. By reading this thread I found a way to create a series of tables that allow me to automate, according to the house and thickness, the values of thickness and radius.

my problem that I can't automate factor k. probably wrong in something as I set the table (see image) by banally inserting the k at the radius and fold degrees.

is there a table to be associated with what I attach as an image in order to automate the value of k or is it a request that cannot be made with sw?

Thank you very much

for bending in air, the factor k goes from 0.3 to 0.5 and is a thickness percentage, starting from the inner side fold.
as the metatto is more easily ironed than compressing, k will never exceed 0.5.
set k a priori, almost always you do not get the desired results, so you need corrections.
to go on the safe, sure and repeatable, I recommend to make a bending test at 90°, but it is valid for all angles, memorizing the material and the tools used, starting from a certain quota (e.g. 100 mm.) measuring the external quotas obtained and the internal radius, detectable also with a tondino and from here calculate the development, ie the quota to remove to the sum of the external quotas to obtain 100.
sheet thickness +rage inside determine the length of straight strokes outside the fold.
therefore the length of that circumference arc of the neutra fiber, its radius and from it is obtained k.
with that material, with that fold made with those tools, k will always be the same and you can put to dwell in the cartiglio, ready to be used later with tranquility.

 

[4L3.8623]

for bending in air, the factor k goes from 0.3 to 0.5 and is a thickness percentage, starting from the inner side fold.
as the metatto is more easily ironed than compressing, k will never exceed 0.5.
set k a priori, almost always you do not get the desired results, so you need corrections.
to go on the safe, sure and repeatable, I recommend to make a bending test at 90°, but it is valid for all angles, memorizing the material and the tools used, starting from a certain quota (e.g. 100 mm.) measuring the external quotas obtained and the internal radius, detectable also with a tondino and from here calculate the development, ie the quota to remove to the sum of the external quotas to obtain 100.
sheet thickness +rage inside determine the length of straight strokes outside the fold.
therefore the length of that circumference arc of the neutra fiber, its radius and from it is obtained k.
with that material, with that fold made with those tools, k will always be the same and you can put to dwell in the cartiglio, ready to be used later with tranquility.

Hi.
thanks for the answer but my problem is not to get the k that we have already done it for all the thicknesses and quarries we use. My problem is to automate my sw steps by not going to insert the k when I go to choose the thickness and the quarry in the table.

I don't know if I explained well at this point... Sorry

 

[re_solidworks]

Hi.
thanks for the answer but my problem is not to get the k that we have already done it for all the thicknesses and quarries we use. My problem is to automate my sw steps by not going to insert the k when I go to choose the thickness and the quarry in the table.

I don't know if I explained well at this point... Sorry

I don't use the tables because they slow down the cad. I used them for a client and sw used a lot to assign them and to edit them. the k factor is to be handled in the gauge tables, you can make of your own and use them.
another problem is that the k factor is adapted to the fold angle. then declare, a factor k with an angle of 15° and the next step to 30°. I don't know how it behaves if the fold is 25°.
In my opinion, they are more disadvantages than the advantages.

 

[Marco F inox]

Hi.
thanks for the answer but my problem is not to get the k that we have already done it for all the thicknesses and quarries we use. My problem is to automate my sw steps by not going to insert the k when I go to choose the thickness and the quarry in the table.

I don't know if I explained well at this point... Sorry

hi, I just wanted to make you understand that it is not enough to choose thickness, quarry and punch, to determine a k, also serve the type of material and the fold angle.
think that the fold angle is much more decisive than the thickness of the material!
as these variables are many, the combinations are endless, so you will never automate your steps on the program, without entering the k.
However, you can standardize a k for similar bends, so as to limit the number and insert them into a table.