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K-factor & Sheetmetal thickness -Relation

L

laiju

New member
Hai ma friends...

Good day to u all... i m working in pro E sheetmetal& I need help of u all to sort out an issue...

Is there any way to link the K factor with sheetmetal thickness...i mean can i give any realtionship between these two..
in short when i change the sheetmetal thickness i want to change Kfactor automatically....


Seeking your valuable help...

Thank you..

Laiju
 
parameters. But the Y and K facters are rleated to temperature in the shop and grain direction of the material and should not need to vary with respect to thikckness.
Edited by: design-engine
 
Thanks for your reply...

But i dont think we get correct development if we use the same K factor for
all thickness ,as far as i know it will vary according to the thickness..
 
Laiju, you are definately correct thatthe K-factor changes with metal thickness.I am relatively new to Pro/E sheetmetal so if you figure this out, please post the solution. Thanks
 
The K-factordepends on the material, the type of bending operation (coining, air-bending).


K =(t/T)


t: distance from inside face to neutral sheet


T: Material Thickness


And is typically between 0.3 to 0.5. For most types of steels it is around 0.33 to 0.4.


I extensively work on sheet metal and i use the value K-Factor = 0.31831 and Y-Factor = 0.5. It gives pretty accurate results. I use WF4.


there is no formula or relation to determine K-factor.


hope this helps u. let me know.


regrds


-Nawaz
Edited by: nawaz
 
We use freeware program called BendWorks to determinate Y and K factor...you can download it here http://www.ciri.org.nz/bendworks/...great staff
smiley36.gif
 
Thanks for the response. I have created my own k-factor calculator using VB and it works very well. However, as Laiju was asking, how can I make my k-factor for say, 16 ga steel, automatically appear when .060" metal thickness is used, rather than having to manually put the k-factor in for each bend?
 
You could have your VB program output the information to a file, then create a mapkey to retrieve the file via the sheetmetal parameters dialog.


Alternatively, convert your VB program to Autoit. This could create the file and start a mapkey to load the created file.
 
You could try using material files. A material file allows you to list a Y-factor or Bend Table as part of it's properties.


So, if you had a seperate material file for each guage of steel (and all other materials you are bending), you could try using that to control your K-factors. So, you would be creating a kind of stock Sheetmetal library.


If that works, you could create a series of "seed parts" to copy from to create new sheetmetal parts depending on what material you want to start with to create the new part.


You would have to see if changing the material would change the K-factor appropriately. (Of course, you still have to change the material thickness.) You could probably create mapkeys or applications to manage this process.


Good luck,


JD
 
Y and K factor are always with respect to material thickness because they are ratios. K factor is always a number between 0 and 1 Usually not below .3 or above .5 ... percentage. Y factor is a percentage of K...

the location of the neutral line varies depending upon the material, temperature in the shop and grain direction. That line runs down the center (or close to the center) of the nominal wall thickness of the sheetmetal part. The percentage distance where that line resides is referred to as the k factor.

Think of a track race around the football field as an example. If you run on the inside you have less distance to run. If you run on the outside you have farther to run.

k factor = t/T where capital T = thickness of the part and the lowercase 't' = the line you take on the running track or some percentage between 'T'.

y factor = k factor * pie/2

The machinery's hand book has three charts for various materials soft to hard for calculating bend allowance. ie. Brass to Cold rolled

I think the K factor comes from that list or something similar.
Edited by: design-engine
 
(Reference picture from Sheetmetaldesign.com)


If I use .42 Kfactor for Mild Steel sheet and bend by Press brake Machine (for 90 deg Bend), will it be correct?
 
That depends upon how warn out the tooling (machinery) is at the shop where they are trusting your flat pattern.... and grain direction of the sheet... and ambient room temperature... and what your tolerances are set too.

Looking at the neutral axis picture you posted makes me think of a plan view of a motorcycle race track. Its about that time of year!
 
I agreed with you. From here, most of the shops have their own Bending Allownace charts. Every charts are not exactly the same.
 
I project I am working on this month is being tooled in Singapore and the ME's that come back always have great stories of incredible food.
 
Bart,

ask your ME's if they have tried the Durians; the fruit? that is banned from the MRT (commuter rail system). Seriously they have signs at the stations saying "No Durians"


DB
 
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