MAKING TUBING USING A "U" & "O" PRESS FORMING PROCESS US 1

[blutoe]

I am attempting to make tubing from flat CNC perforated and parted blanks. My material thickness range is prolific - from 0.025" to 0.125" across a small amount of cold rolled steel, but significant population of stainless steels (301, 304, 17 - 7 PH) and a significant population of aluminum (3003 h-14, 2024 0 and T 3 / 4 temper, 6061 0 and T -6 and 7075)

While I am being some what succesful in the cold rolled and the 3003 h-14, I am experiencing ovality (roundness) issues on the stainless and tougher aluminums.

I am initially creating a Butt Seam tube. The butt seam is held to a 0.0" to 0.005" allowable gap. This does not seem to be as hard to acheive as originally thought. Later on it will be welded. However, for now I must be succesful at getting the best roundness possible.

Does anyone have any experience in this domain. I am using old practices to make "U" & "O" formed tubes. However, I have created a machine to do it more efficently, automatically with transfer automation. My diameter range is as prolific as my materials. I work from minimum O D. of 0.317" to max. O. D. of 3.740" in lengthss as short as 0.800" to 13.0"

 

[weir]

I have seen this done on a 100ton press with 16SWG Stainless perforated sheet which was used to build into a car exhaust (muffler) system .The tool had a floating mandrel and a flat sheet was put into the tool under the mandrel and one stroke hammered down to make the tube round and the seam was resistance seam welded.The actual quality roundness etc I cannot say but it covered a range of tube sizes with interchangable parts etc,

 

[235]

Have you considered Roll Forming?
dako@kolev.com