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Helical sweep of datum curve?

mekaneck

New member
I am trying to model a helical gear using a true involute profile, but I cannot figure out how to create a helical sweep of a datum curve. I had to create the involute tooth profile using an equation, but now I cannot sweep it along a helical path because I cannot use the use edge in sketcher because it cannot move the geometry of the datum curve.



Below is a picture of my setup:



View attachment 148



I have tried a regular sweep, a VSS, a helical sweep, making one side of the tooth at a time with a surface, etc. but to no avail. I am using 2001.
 

mekaneck

New member
I'd still like to find a way to do this. In the equation for the curves, I can control the angle of the curve about the axis of the gear, and I can control the depth (both with variables). I would think that this would be all that is needed to make this possible, but there is no way to get ProE to drive either of the variables in a sweep.



Here are some related questions that could help:



Is it possible to sketch an equation without using a datum curve (i.e. in sketcher)?



Is it possible to twist a surface or solid geometry (if I made a spur gear, could I somehow twist it to make it into a helical gear) ?



Thanks in advance for any help.
 

mekaneck

New member
Well, I think I've got something that'll work -



I used the copy geometry tool in sketcher to copy my datum curve, then (while still in sketcher) I selected that copied curve and used the rotate/scale tool to rotate the curve, and then I used that angular dimension in conjunction with the trajpar variable in a VSS.



When I rotated the curve, it looks like it broke it up into a bunch of smaller arcs, but they all act as a single entity when I select it, so I don't know if this is still a true involute curve or just a representation, but it's as close as I'm going to get.



Any other ways to go about this would still be appreciated.
 

tinag

New member
I downloaded a gear several days ago. It is a helical gear but the angle of the sweep is adjustable so that you can change it into a spur gear. If you want i can send you a copy of this gear.



It may help you to find out how it is done.



Tinag
 

mekaneck

New member
I've looked at that one before. It helped me get started, but it doesn't have a true involute tooth, and it is also done with a swept blend. I am looking for a way to make the actual geometry, not an approximation.



I appreciate the help though.
 

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