I know it's an old problem but, did anyone actually find a solution that doesn't involve playing around with code, re-writing bend tolerances or reinventing the K-Factor? I have a simple steel pipe in sheet metal that I have "ripped" to obtain the flat pattern. The correct length should be 314.16 mm when made flat, however, Inventor says it should be nearly 4 mm shorter! This is definitely incorrect......
How thick is your rip, because you'll lose some material there?
Are you simply doing a flat pattern or you're using code to measure this?
Inventor Certified ProfessionalIt'll take material stretch into consideration as well so it won't be identical.
Inventor Certified ProfessionalAlso you are calculating the OD at 314.1593, but remember the ID is 307.8761.
The centre line of this is 311.0177.
4mm difference is probably right.
Inventor Certified Professional Inventor Certified ProfessionalIf you think about it like this:
If you have an L shaped piece. There is one bend and a slight amount of stretch/compression.
In a cylinder, every single part of that metal sheet is stretched/compressed to form a circle. This is going to = a much bigger difference.
Inventor Certified ProfessionalNow how can that be?
Examine the Attached file.
If we start with a 100mm*PI flat sheet
how can it be three different arc lengths when bend?
OD is different than ID and both are different than mid-surface length???
Where did the material go?
(Don't look at next post until these questions are pondered.)
Yes, but what I'm saying is that if you use the default K factor as in the real world you get the 310mm that the OP says is wrong. If you set the K factor to 1, you get the 314.159mm that is obtained from simply measuring the circumference.
Inventor Certified Professional
