anyone know what mean by this statement/rule?

[x]

hi guys..
I am a rookie in this formula sae..and have read the rules..but i dont understand what this rule mean..

"The minimum radius of any bend, measured at the tube centerline, must be at least three times the tube outside diameter. Bends must be smoothe and continuous with no evidence of crimping or wall failure"

can somebody help me?

[DaveC]

The minimum radius of any bend, measured at the tube centerline

self explanatory. centerpoint of bend circle radius measured to center of tube.


must be at least three times the tube outside diameter.

aforementioned radius must be greater or equal to 3 x the tube diameter you are bending. If you bend a 2" tube, the bend radius must be at least 6".


Bends must be smoothe and continuous with no evidence of crimping or wall failure

Dont use a exhaust or pipe bender to bend your tubing. Use a bender designed for automotive fabrication. There are many inexpensive ones, such as made by JD squared or Pro Tools. So, the tube must stay cylindrical in shape, with a minimum of crushing or ovalizing in the bend area. If you want to see what it shouldn't look like, look at OEM exhaust systems on any car, or check out the bends your local muffler shop makes, then look at "mandrel bent" stuff for comparison.

[x]

tq DaveC for helping me!