End Angle for Helix

[MimiN63]

I have a cooling coil part for which I created a helix. It's revolved 4x and the height is 4.5". I started the helix @ 240 degrees on a face of an existing sweep b/c the first 30 degrees at either end of the coil are a smaller diameter than the rest. This worked fine for the start of the helix ("Start angle. Sets where to start the first turn on the sketched circle." - from Help) Does anyone know how to achieve an "end angle"? There doesn't seem to be a setting for this and SW completes the 4th revolution to end @ 270 degrees. I tried revolve-cut using both a regular sketch and then a 3D sketch with no luck. Has anyone had to do this before? Any suggestions appreciated.

 

[MimiN63]

Sorry, forgot to mention that I also tried a sweep to cut away the material. I think that's the way to go, I just can get the spline in my 3D sketch to line up with the helix's axis. I'm looking for suggestions on what kind of relations to create between my spline and the helix.
Thanks

 

[TheTick]

I always start helixes (usually springs) with a layout sketch for start and end angles first. Then I use equations to link start and end positions with spring parameters for number of coils and start position.

 

[CorBlimeyLimey]

The end angle would be controlled by the number of revolutions! If you are starting @ 240° & wanted to end at 270°, choose the Height & Revolution option in the Helix/Spiral manager and set the number of revs to 3.9166667. (4 revs - ((270-240)/360))


Eng-Tips.com Forum Policies faq731-376
Making the best use of this Forum. faq559-716
How to get answers to your SW questions. faq559-1091
Helpful SW websites every user should be aware of. faq559-520

 

[MimiN63]

Thankyou CorBlimey! That's exactly what I was looking for! Can I combine that with the info from The Tick and incorporate it into an equation so if the angle dimension (for start/end) in the layout sketch changed, you're equation would change also?

 

[CorBlimeyLimey]

Yes ... basically the same information is used. A layout sketch is an excellent method to use for all parts & assemblies.


Eng-Tips.com Forum Policies faq731-376
Making the best use of this Forum. faq559-716
How to get answers to your SW questions. faq559-1091
Helpful SW websites every user should be aware of. faq559-520

 

[TheTick]

Food for thought...

<

http://www.esoxrepublic.com/models/>

Download & examine the file TorsionSpringByTheTick

 

[CorBlimeyLimey]

Oh, thanks Tick!!! I thought about it & now I'm hungry ... darn it ... I'm trying to lose weight.


Eng-Tips.com Forum Policies faq731-376
Making the best use of this Forum. faq559-716
How to get answers to your SW questions. faq559-1091
Helpful SW websites every user should be aware of. faq559-520