TUTORIAL: How to create a tapered helix

[bigseb]

To create a tapered helix in Alibre start you must first create a cone that has the same height, major diameter and minor diameter as your tapered helix.

 

[bigseb]

Next you will need to create a helical boss. Important here is that profile sketch passes through both the major and minor radii of the cone (as in the image below). I generally start helix somewhat below the cone and end it somewhat higher. This ensures that the helix passes through the cone completely.

 

[bigseb]

The result will look something like this:

 

[bigseb]

Now the fiddly bit. Create a 3D sketch. Press the 'Project to sketch' button, Now select an edge where the helix intersects the cone. Press 'Ok'. Your resultant sketch should look like this:

 

[bigseb]

Now suppress both the cone and the helix, leaving just the 3D sketch active.

 

[bigseb]

Create a profile sketch (cross-section) of your tapered helix.

 

[bigseb]

Lastly create a sweep using the two active sketches as your profile and path. Et voila... a tapered helix.

 

[bigseb]

This is a very handy tool and can be applied in many different ways. You can see another example of this here. Other areas where I have used this method are: tyre treads and support ribs/contouring over non-planar surfaces.

 

[jhiker]

Nice! I didn't realise you could use 'project to sketch' in that way...

 

[DavidJ]

The method is really useful for lots of things, but there is an easier way to make a tapered helix - just use the taper option in the helical tools.

 

[bigseb]

The method is really useful for lots of things, but there is an easier way to make a tapered helix - just use the taper option in the helical tools.

Yeah, the tapered helix done this way is just an example of how to apply a method.

 

[tome]

When I create the helix in the last step I get this error. What am I doing wrong?