Turning a swept cylinder into a sheet metal tube

peter_cuthbert

I was kindly shown how to get my simple sweep based funnel correct in the Question "Extending a sweep tube to a non right angled plane".  That is visually satisfactory but I now want to create it as a Sheet Metal model.  I have tried a variety of ways of attacking the problem all of which refuse to allow me to use Sheet Metal.  There will, no doubt be a simple solution, but I have not been able to discover it.

The specification of the funnel is shown in centre of the picture below.  It is 500mm tall, has an outside diameter of 159mm and is meant to made of 0.5mm stainless steel.

My latest attempt is here, drawn upside down as it seemed easier to sort out the split for the funnel cant at the top of the drawing:

https://cad.onshape.com/documents/5790e503304bd74ca70fccc1/w/95f5e15da43f8508616ebdf5/e/5d12f73aae218379ea1953c0

Regards

Pete

eric_pesty

You need a split somewhere to tell it where the seam is.

Here's one way to do it: https://cad.onshape.com/documents/2ec3fd388bed33edb147e23a/w/eea5fe265b396c4a4b638715/e/b57b506b6a1b54f7babb039e?renderMode=0&tangentEdgeStyle=1&rightPanel=configPanel&uiState=668dd60235dcdb1f85973709

peter_cuthbert

Hi Eric

Thanks for your suggestion.  That sounds very sensible, though I cannot, in my drawing, seem to persuade Split to accept a line down the side of the tube which was created in Sketch. I put a plane against the side of the tube and sketched it on that including a point on the cicle that defines the tube. So I feel pretty confident that the line is on the surface of the tube.  A bit of a mystery to me.

In frustration I stuck a plane through the centre line of the tube and then drew a shallow rectangle the length of the tube where the line had been which I then extruded to a negligible width.  That was accepted by Split and has cut the tube into two pieces even though the 'split bar' only pierced on side.  Clearly there is more to learn about the way that Split works as it seems to be quite different to split in 2D.

Best wishes

Pete

martin_kopplow

Peter, try your rectangle-trick from the end or a cross section of the tube, not the side of the tube and you will be able to just affect one side. Or modify the sketch of the tube to incorporate the tiny gap right from the start. That way, you could do all sort of details. https://cad.onshape.com/documents/ec94dfae07631e567148cc8e/w/6f6ad0d119fc07ec290befeb/e/fbefaacbcbc5f5747be12b49?renderMode=0&rightPanel=sheetMetalPanel&uiState=668fcb9a86755679e31f4fc7