Autodesk Inventor Users

Thats Great you do know about the work involved.

But some times I have to educate the Customers about this and then they wonder that the part "unique" cost so much.

Well it must contain all the factors needed to reproduce the part.

No sharp bends with no radius.

What material.

The more info the quicker and more accurate the part can be produced which all comes down to the Cost factor.

K-Factor– A constant determined by dividing the thickness of the sheet by the location of the neutral axis, which is the part of sheet metal that does not change length. So if the thickness of the sheet was a distance of T = 1 mm and the location of the neutral axis was a distance of t = 0.5 mm measured from the inside bend, then you would have a K-Factor of t/T = 0.5/1 = 0.5.

Yes this is how to determine the "default" K factor but as you know each and every material has its own K factor Aluminium is different from Steel although the thickness can be the same, so only accurate tests done on your Brake press will be correct, even different Angles will effect your K factor.

We did tests from 0° to 180° with a increment of 10° to build our Datenbank using all the standard Materials.

Even then if Customer wanted a very precise angle or material then then further test would be carried out

We produce a lot of sheet metal work using Invento and use 0.2732 for below 3mm sheet and 0.3365 for 3mm and above, using ilogic we automatically set the k-factor depending on the thk of material so we don't forget to adjust it each time.

The k-factors mentioned  are to suit our own press and tools of course.

Nice question

You can either:

1. Do experiments on different plate material and thicknesses to build a database for yourself.
2. Use ready made, reliable databases built by others which is either shared freely or purchased.
3. Or use a default K-Factor, then correct during the fabrication process.

Thanks

Strange you people The K-factor depends on many factors. This is known by every manufacturer.

1. The thickness of the material, for example, a sheet of 1 mm which we lay in the model may be in fact 0.93-1.07 mm, according to the requirements for the production of these sheets.

2. From leasing a sheet. It is hot rolling or cold.

3. Type and condition of the bending machine.

4. The material itself may fluctuate in certain tolerances.

These factors are insignificant when one bend is made, but if they are many, then they affect the exact details very much.

Therefore, for details with a large number of flexors, it is necessary to correct the rhorda whenever one of these parameters changes.

Дивні ви люди К-фактор залежить від багатьох факторів. Це знає кожний виробник. 

1. Товщина матеріалу на приклад лист 1 мм який ми закладуємо у моделі може бути по факту 0.93-1.07 мм це по вимогам до виготовлення даних листів.

2. Від прокату листа. Це горячий прокат чи холодний. 

3. Тип і стан гибочної машини.

4. Сам матеріал може коливатися в певних допусках.

Ці фактори незначні коли робится один згин але якщо їх багато то вони впливають на точні деталі дуже сильно. 

Тому для деталей з великою кількістю згинів потрібно коригувати рогортку кожен  раз коли змінюється хоч один із цих параметрів.

Hi,

i using Inventor. My k-factors are (TRUMPF edge-bender machines):

steel (Fe235) 0.35

steel (Zinc-coated Fe Po2G Z275 NA) 0.33

stainless steel (1.4301) 0.44

copper (cu-Ep) 0.37

aluminium (AlMg3) 0.44

In my personal opinion I agree with the comments that state the fact there is not a default "K-factor", Because its certainly true this "K-Factor" is a variable in so many ways that is practically impossible to define one that covers all the variables:machines, materials, thickness, temperature of the material to bend, angle to bend and of course the accuracy of the design and the bending process. This last one, with all the respect, goes under the skill of the person if is a manual process.

The K-factor is a good approximation to the reality, perfection or the ideal state is practically impossible and there is a difference between modelling something in our little CAD world and Build something.

In this sense, I will recommend the use of the Bend Tables, that is an empirical method of the process of bending a material, because is based on the Real Final Object that a manufacturer can achieve with their current conditions (machines, skills, materials, etc) Autodesk Inventor as an excellent tool for this task will compile all this data obtain during the process of generate the bend table that will accurately take into consideration also the tolerances of fabrication in order to replicate the real scenario trough a virtual prototype.

I would say all the methods are valid, but only if is done trying to be close the reality as much as possible, for example:

We have to model a component into any software (Catia, Inventor, AutoCAD, Rhino, etc) Question? How many times do we perform measurements of a diameter for example?? in order to type the correct dimensional constraint in the model?

Hello

this very useful

by

ww.mc-cad.it

We cut out out 5" x 10" inch parts for each material and thickness on our Trumpf laser. So, 36 parts total, 12 Stainless, 12 Hot rolled steel, and 12 aluminum for each of the following thicknesses.

!/2", 3/8", 1/4", 7g, 8g, 10g, 11g, 12g, 14g, 16g, 18g, and 20g.

We bent all of the pieces centerline to 90°. Then we measured them all on our CMM to create a universal k factor that all engineers use now, this is a reference dimension, obviously there will be variation depending on several factors but this should at least get you close.

many suppliers give me the drawings with a "neutral" factor, that is to say (for thicknesses up to 3mm) I remove the thickness for each bend and I use the inside rag of the fold with the same value as the thickness. Using inventor, to get this, I use a factor of 0.274

see

https://apps.autodesk.com/INVNTOR/en/Detail/Index?id=3866959561356165269&appLang=en&os=Win32_64

DKP-HRU

1,2 MM-0,273

1,5 MM-0,4

2 MM-0,465

2,5 MM-0,428

3 MM-0,423

4 MM-0,415

5 MM-0,4

6 MM-0,379

7 MM-0,365

8 MM-0,353

9 MM-0,344

10 MM-0,337

ALMİNYUM

1,2 MM-0,273

1,5 MM-0,525

2 MM-0,59

3 MM-0,53

4 MM-0,495

YILLARDIR KULANDIĞM K FAKTORLERİ BU GÜNE KADAR HİÇ SORUN YAŞAMADIM

I design components for machines using the default Inventor K-factor. I farm out most all sheet metal work so I don’t have much control over the equipment and processes. It wouldn’t do me much good to develop accurate bend tables. As a result, I do the sheet metal design based upon a fairly loose tolerance. The only critical dimensions I allow are on the base face. I avoid anything attaching to subsequent flanges if possible. And only if adjustment or other means of dealing with the inaccuracy is employed.

I’ve designed sheet metal in the past. Long before the proliferation of CAD. It had to be accurate and I spent a great deal of time developing bend tables. I can do it. I just choose not to.

I realize there are many designs that require accurate bends and the requisite k-factor development. But I feel oftentimes designs could be tweaked to not require such accuracy. In which case, a default k-factor works just fine.

Here at Vanriet UK we us

0.2732 for 0.5 to 2mm

0.3365 for 2.1 to 6mm

These values are to suit our own machines

Grabcad model

Sheet Metal

Sheet Metal Styles Template for Inventor 2023. It also has I-logic rule to have the "Unfold Method" as an iproperty so that you can have it in your drawing.

This is my sheet metal styles template that I created. Your bend radius also affects your K-factor so I made multiple unfold rules for the same material, depends on my desired radius.

Hello Everyone,

I created a 3D model for a cylindrical planter and need to create its flat pattern,

Could anyone help me plz?