×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

How do I attach Helix curve parametrically?

How do I attach Helix curve parametrically?

How do I attach Helix curve parametrically?

(OP)
Hi guys,

Hope you can help. I have created a thread using the sweep command around a helix curve on a shaft. I want to attach the helix to the end of the shaft so that when I increase the shaft length, the helix will follow.

Any ideas?

Many thanks,

Andy.
 

---------------------
(Using: UG NX4)
Design Engineer
 

RE: How do I attach Helix curve parametrically?

The answer(s) you get will depend on what you mean by the helix 'following' the shaft. Do you mean that the helix length increases to match the new length of the shaft, or that the helix length stays the same but just moves to stay attached to the end of the shaft?

RE: How do I attach Helix curve parametrically?

(OP)
Hi Cowski,

Sorry, I should have been more specific. I want the helix to stay the same length but stay attached to the end of the shaft when the shaft length is increased.

Many thanks,

Andy.

---------------------
(Using: UG NX4)
Design Engineer
 

RE: How do I attach Helix curve parametrically?

The best solution at the moment is to make the fixed end of the shaft and the location of the helix the same point.

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: How do I attach Helix curve parametrically?

I agree with John, but if this situation is not possible there is at least 1 work around available. Make the helix and swept features much longer than you need (in both directions) then attach a datum plane to the end of the shaft (assuming the end is flat) and another datum plane offset from the first by the length of the thread, then trim the swept feature by the datum planes before you unite it. A couple of drawbacks to this approach (other than not being a very 'clean' solution) is
1) the thread start/end will rotate as the shaft length changes - this may or may not be important to your application
2) it will not work so well for a tapered thread.

RE: How do I attach Helix curve parametrically?

Any of these are in the right ballpark. I seem to remember working though an example with a previous poster that you may be able to search for. I think the proposal was that you either build the model around the base of the helix because that won't move, or you link in a model of the thread based on a mated part containing that geometry.

Cheers Hudson

RE: How do I attach Helix curve parametrically?

Well starting with NX 5, there's another scheme that will allow you to create literally anything and make it's origin associative to some other body.

That function is the new 'Instance Geometry' command.

What you do is create your Helix (or any object) and then create the item that you wish to associate it to.  Then using Instance Geometry you do a 'Point to Point' transform and select appropriate references points on both the helix and the object you wish to associate to and make a single 'Associative' copy.  Granted, you will technically have TWO Helical curves, but you can hide the original one and just edit it by it's expressions, and of course the other will update since it's an instance of the original.  And since the copy is not located relative to the point you selected on the body, if you edit it in such a manner that this point moves, the helix will also move.

Anyway, we've now got another tool to help create objects which you can associate to other objects.

John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: How do I attach Helix curve parametrically?

(OP)
Hi all,

Many thanks for all your responses. There's plenty to think about so I'll give some of your ideas a go.

John - we're upgrading to NX5 anytime now, so in the future I'll be able to use the 'Instance Geometry' method.

Regards,

Andy.

---------------------
(Using: UG NX4)
Design Engineer
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources