Definining a Datum Plane tangential to 2 Surfaces
Definining a Datum Plane tangential to 2 Surfaces
(OP)
This is my first posting to this forum, despite having been a follower of the various postings for a couple of years. I have decided to bite the bullet and sign up.
I am using NX4 currently, and have been using UG since V9 days, but this problem has me stumped. I am attempting to construct a datum plane tangential to 2 surfaces of revolution, at an angle to another already defined datum plane. To put the problem in context, the surfaces of revolution are the front and rear tyres, the defined datum plane is the vertical plane of symmetry of a bike, and the angle is the lean angle of the bike. The final datum plane is to conduct a clearance check between the bike and the road surface.
Any suggestions?
I am using NX4 currently, and have been using UG since V9 days, but this problem has me stumped. I am attempting to construct a datum plane tangential to 2 surfaces of revolution, at an angle to another already defined datum plane. To put the problem in context, the surfaces of revolution are the front and rear tyres, the defined datum plane is the vertical plane of symmetry of a bike, and the angle is the lean angle of the bike. The final datum plane is to conduct a clearance check between the bike and the road surface.
Any suggestions?





RE: Definining a Datum Plane tangential to 2 Surfaces
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/
RE: Definining a Datum Plane tangential to 2 Surfaces
I have uploaded a picture, hope it worked!
The front and rear tyres are shown, the datum plane I need is between the front and rear contact patches, at an angle to the vertical datum plane shown.
Note that the front and rear tyres are completely different sizes and profiles
RE: Definining a Datum Plane tangential to 2 Surfaces
Spot the newbie: this time I read the instructions!
RE: Definining a Datum Plane tangential to 2 Surfaces
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/
RE: Definining a Datum Plane tangential to 2 Surfaces
I have copied the relevant items to the attached file
RE: Definining a Datum Plane tangential to 2 Surfaces
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/
RE: Definining a Datum Plane tangential to 2 Surfaces
That was the answer that I was dreading. The addition of a value for the angle would give 2 unique solutions – one at the top of the tyres and one at the bottom (or 4 solutions if you consider both sides of the vehicle), but, as you say, there is no way to input that information. Unfortunately, as the tyre profile and the tyre positions are variables, as is the lean angle, constructing the plane ‘longhand’ is going to be difficult and tedious.
But thanks for trying, anyway.
RE: Definining a Datum Plane tangential to 2 Surfaces
I am treating this as similar to a ground lines setup for automotive design. I have altered your model slightly by breaking the links and moving the small wheel off the same plane as the other one to make the example slightly more complex but clearer I think. The whole thing has been set up with a few associative curves in NX-5. You will notice a couple of suppressed offset features which you can toggle on and off to prove that the construction is in fact associative. One created the tangent line is unlikely to change sides unless you more one of the features fairly dramatically.
See how you go
Regards
Hudson
RE: Definining a Datum Plane tangential to 2 Surfaces
Thank you for your reply, which, unfortunately, I won't be able to study until I get into the office after the Easter break, as it is from a later version of NX to the one I have here.
RE: Definining a Datum Plane tangential to 2 Surfaces
Similar method probably refined over what I did in NX-5 this one is in NX-4, second time lucky
Regards
Hudson
RE: Definining a Datum Plane tangential to 2 Surfaces
RE: Definining a Datum Plane tangential to 2 Surfaces
RE: Definining a Datum Plane tangential to 2 Surfaces
Certainly the solution is good enough to figure out that the area where I thought I would have a clearance issue is quids in, and another area that I hadn’t considered had a foul condition with the road surface – fortunately, by catching it early, the problem was solved by a minor design tweek.
Thanks to all for their replies.