How do I bridge a gap?

[enginerd1959]

I'm trying to connect 2 cylindrical objects, but one is also helical (a spring) so I'm not sure how to make a guide path that's perpendicular to both ends.

But the "Bridge" doesn't have to be perfectly tangent. I'm just throwing together concepts for a rainstorming session, so if you have a quick & dirty way to sort of fake it, that's okay.

 

[cowski]

I usually use the "tube" command to make spring like objects. Start with your helix for the spring, make lines for your spring legs, use bridge curve to connect them, and finally use the tube command to make it a solid.

 

[JohnRBaker]

Unless the 'straight' sections do NOT line up with the ends of the 'helical' section, I can't see what your problem is. Granted, the ends of the helical section are not normal to the direction of the straight sections (close but not perfectly aligned) but a simple surface through curves with tangency control should do the trick.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
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.

 

[hudson888]

You're probably as well to come to grips with this simple geometry and construct something akin to the attached and/or use it as a template by manipulating parameters to achieve your desired results.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[enginerd1959]

Thanks guys,

John - I don't know anything about mesh surfaces. I tried experimenting with the command & reading the help file but I'm totally lost. I probably need more advanced training, but 99% of what we do here is simple Extrudes, Revolves, etc.

Hudson - it appears your sample .PRT is from a newer version of NX. We run NX4.

I "faked" it with a simple extrude to bridge the gap. It doesn't line up perfectly on the coil side, but you can't tell unless you zoom way in. My manager is happy so I'm just going to move on.

 

[JohnRBaker]

I suggested using 'Surface Through Curves', which is not the same as 'Surface Through Curve Mesh'. In the case of 'Surface Through Curves', all you need is a start and end profile, while in 'Surface Through Curve Mesh' you need profile curves going in both the U & V directions, thus the use of the term 'Mesh'.

Attached is a simple example.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
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.

 

[enginerd1959]

Sorry - I should have read your reply more carefully. I was at least able to get something to appear with "Surface Through Curves" but it's twisted.

 

[enginerd1959]

I figured out the twist problem. I chose "Angle" alignment & picked the center of the 2 circles. I don't understand why it worked, but it did.

I finished by uniting the various bits.

 

[JohnRBaker]

When you select the profiles, an indication is given showing the 'direction' of the curve. The direction of all of the profiles must be going in the same direction. When you select the second profile, if it appears to be going in the opposite direction that that first profile was going, there is an option to reverse the 'sense' of the curves direction. Select it and see if this helps. BTW, if you still have that twisted model, you edit the feature and reverse one the 'sense' of one of the profile curves, which may fix your model.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
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.

 

[enginerd1959]

John,

Is there a reverse button in the Through Curves dialog box in NX4? I can't find it.

 

[JohnRBaker]

You're right, the 'Reverse Direction' button was not added to the Surface Through Curves dialog until NX 5.0. In NX 4.0 what you had to do was if the direction of a pick was wrong, you had to 'Delete' that 'Section (String)' and reselect it on the opposite side of the displayed arrow so as to reverse the 'sense' of the profile. It may take a bit of getting used to, but it can be done. Granted, the button to reverse the direction is much easier, which of course is why we added it to NX 5.0.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
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.

 

[MickyV007]

You can always use the divide face feature to a circular surface, then you have more control to where the directional arrows will attach. See example.

Best regards,

Michäël.

NX4.0.4.2 MP10 / TCE 9.1.3.8_build_0711 / NX6.0.5.3 + TC8.1 Unified / NX7.0.0.9

Belgium

 

[cowski]

I had a few spare moments this morning so I dusted off NX2 to make an example file that used bridge curves and the tube (or cable) command. This is just a very basic example, if needed you can make it more robust with sketches, expressions, and such.