Internal Helical Spline

[Spurs]

I am tring to model a helical internal spline using SolidWorks 2003. (Much like a nut)


The steps that I have gone through is to first create the spline geometry and then I created the spiral helical curve. I then swept the geometry through the helical curve to create an external spline model. No problem so far.

Next I edited the original spline sketch to add a perimeter circle larger than the spline sketch (in order to create the outside boundries of the nut) to change the spline from an external to an internal. - I hope your with me so far.

When I close the sketch, I get the following error

"Sweep Operation Failed to Complete"

It doesnt give me a hint at what is wrong.

I have tried using the geometry without the helix - ie. just extrude to create an internal spur spline - no problem.

To verify if it is geometry related, I have done the following:

Created a new part

sketched two concentric cicles on one sketch

created a spiral helix path

then tried to sweep the sketch of the two circles through the helical path - I get the same error - "Sweep Operation Failed to Complete"

If i eliminate the outer circle from the sketch - I can model a 3D cylinder.

What am i missing to get this internal helix made? Is this a quirk in Solidworks 2003

I used to be able to do this in SolidWorks 2000.

Any help would be appreciated

 

[CorBlimeyLimey]

I’m confused, but then that’s not unusual for me lately. You lost me when you tried to change the sex of the spline. I don’t believe SW can do what you are trying to do, in the way that you are trying to do it.

I’m still not sure if you’re trying to produce a male (more material) or female (less material) spline inside a hole, but either way the basic method is the same.

Create the solid “nut” with a plain hole.
Create the helix sketch with the start & stop points as required.
Create the spline profile sketch. (adding the pierce relation to the helix if needed)

Then, if you want a male spline use the regular sweep-extrude.
Or, if you want a female spline use “Insert>Cut>Sweep”.
NOTE: You may have to play with the end surfaces of the spline.

Hope this helps.



CorBlimeyLimey
Barrie, Ontario
faq559-863

 

[Spurs]

Thank you sir

You have been most helpful.

The sex change method that I used previously works for spur profiles, but not for helical profiles. I guess thats what got me down that track which ended up being a dead end.

Your method worked wonderfully.

Thanks