I am curious to know if i is possible to draw a spiral, select an end node and pull it up (or down) to create a helical cone. I know there is a way to create a tapered helix, but I just want to know if there is an alternative. Say, selecting the node and entering a height to spread it along that height while maintaining a nicely spaced coil. Hope that makes sense.
I just want to pull up on the 2D spiral to stretch it
Flat
Pulled up
Morning Don
I see. I don't think it is possible directly.. but you could probably set up a sketch with an unconstrained sketch point - and then make the helix intelligent enough to always hit the target.
It would mean doing quite a bit of work yourself in the background. So I would ask is it worth the effort over using Instand3d?
I wonder why you want this.. what is the use case?
[edit] my bad - instant 3d will cause the helix to expand.. Now I get it - let me have a play
Hi Don
This is a bit messy - and could be more sophisticated but uses the approach I first suggested - it's too early in the morning for equations
2018 attached
I do it like this:
Of course, you can use a cone as a surface, but I wanted to show that this method also offers other possibilities
Cone:
much better
Thank you Rob
Underlying geometry of the spiral is a polygon if try to pull this is what will happen.
Maha Nadarasa wrote:
Underlying geometry of the spiral is a polygon if try to pull this is what will happen.
This is soo crazy it's actually brilliant!!
Thank you everyone for having a look and offering your thoughts. The question was just something that came up in the TurboCAD user forum and the replies there are similar to what you guys have said. I do have quite a bit of experience with SolidWorks and couldn't think of a tool that would do what the fellow was after so just thought I'd ask. If you are interested in the TC discussion it is at the link below. It is getting too involved in math to hold my interest. I am glad that I personally don't need to find an answer, but like many of you , I am often just curious about what others are trying to achieve.
https://forums.turbocad.com/index.php/topic,27428.0/topicseen.html
Thanks Don for curiosity I had a quick look..
It reminded me of this approach I came up with years ago when working on a curved staircase
I've recreated the approach here with a spiral just for kicks
Lofted Bends
Unfold and cut
Fold it back up and convert the edge
The staircase was a weird thing, straight against a wall on one side but flaring out at the bottom.
I spent days trying to get the perfect walkline up the center.. this was how I eventually achieved it.
You have to mess with the k-factor and set it to zero or 1
I think on my model I had a piece of sheet metal 3m square and 0.01 thick like a giant piece of foil.
Thanks for your interest Rob. I will direct the TC user here for a look and perhaps that will help help him with another approach to try.
This is such a great forum! Thanks!
Don Cheke wrote:
This is such a great forum!
It sure is without it I'd have given up years ago
Hi Don
I'm not sure I understand your question - but you can have fun intersecting surface bodies using Tools > Sketch Tools > Intersection Curve or equivalently converting model edges after a trim or up to surface extrude, etc