Twisting a Spiral

Is it possible to twist a Spiral (Helix) around a cylinder that has a slight revolved shape to it? Does there a Power Point, or any other tutorial Exist that would demonstrate the principle, maybe? Wrapping a Helicoil around a straight shank as in cutting or extruding a threaded bolt is not a problem for me, but never have I done it with the shank having an irregular shape. I do not remember ever having covered this in my training, or I have missed something here. Cannot find any thing that resembles this situation in my books. I would welcome any advice from the many skilled people here on this. Thanking you, Erika Layne

I've got an example of this on my website. The site is getting a little old and rickety, looks like some broken links, but you can still get the part, and it should show you what you need to know.

mysite.verizon.net/mjlombard

Go to the SWParts link, and its the one with the caption that says "Things you shouldn't do with sheet metal". It's actually a sheetmetal part, but it uses a spiral around a non-cylindrical shape.

Matt

Hi Erika

I'm not sure I can visualise "cylinder that has a slight revolved shape to it"

There is a swept helix around a Hour Glass that I modelled to help someone some time ago on my website. This may be of some use let me know if it isn't.

If John and Matt's examples don't do it for you, try Mike Wilson's site, where there are a number of parts that might help.

I made a quick tutorial Flash video yesterday, if anyone else is interested.

The Flash file is reasonably large, 20Mb, so I hope you have broadband!