Sheet Metal Cylinder - "Creating" & "Flatten" Question

[vertical horizons]

I need to create a cylinder that is 30"Ø, 36.00" tall, with a wall thickness of 0.25".

I don't see where to set the wall thickness.

 

 

 

 

 

Here is the procedure I followed:

• Start a new part;
  
• Go to SHEET METAL > BASE FLANGE/TAB;
  
• Select the Top Plane;
  
• Select CIRCLE;
  
• Create a circle that is 30.00"Ø,
  
• Exit SKETCH;
  
• For Sheet Metal Parameters, I enter 36.00" to make the cylinder height 36.00";
  

This is where I get confused.

I do not know what the K-Factor & the Auto Relief are, or what they do.

 

I do not see where I would specify that the wall thickness should be 0.25".

 

Am I supposed to specify the wall thickness on this page, or is there another place to place that dimension?

 

******************************

 

Once this cylinder is created, I also need to be able to unfold (or flatten) it.

 

 

Is there a better way to create this cylinder, that will allow me to FLATTEN it?

[vertical horizons]

I found a way to create the cylinder, but I don't know if this is the correct way to do it.

 

I sketched a circle that was 30.00"Ø.

 

Then, I trimmed out 1/8" out of the circumference of the circle, so that, now the circle was not a complete circle.

I then went to SHEET METAL, and created the 36" tall cylinder, with a 0.25" wall thickness.

 

 

The cylinder will now FLATTEN, and UNFLATTEN.

I just have to remember that when I need to know the length of the cylinder, when it's flattened, I have to ADD the 1/8" that I originally removed from the circle.

 

 

This is the end result.

 

If this is NOT the correct method, someone please let me know.

Edited January 9, 2014 by vertical horizons
Adding Images For Clarity

[vertical horizons]

Actually, I was just informed that, when they construct a cylinder, they will roll the steel to where the 2 ends almost meet, leaving the 2 ends 1/8" apart from each other, to allow for welding. So, I guess, until someone shows me a better way to create a cylinder, this way will have to do.

[stevsmith]

Hi Vert,

Unfortunately, this is the correct way to do a rolled cylinder in Solidworks (e.g. creating a circle and breaking it at a point.

 

The exact K-Factor is dependent to your Brake Press tooling and forming methods. It may vary from company to company and machine manufacturer. I'll try and give the layman's terms.

 

K-Factor is the expression given to the to point in the thickness of the material where there is no-compression. the k-factor itself relates to a percentage of the thickness of the material:

e.g. 44% = 0.44, 50% = 0.50 etc.etc

 

This percentage is taken from the inside radii when formed.

 

Generally material under 3mm has a k-factor of 0.44 but then again this depends on the material used (alloy, M/S or St/St)

 

http://sheetmetal.me/k-factor/

 

http://designandmotion.net/design-2/manufacturing-design/sheet-metal-k-factor/