Trimming Tubes

[mandalores]

Hey guys.

I'm CADing a space frame for a car and I am having trouble finding a good solution for trimming\extending the tubes to they meet in a nice way where I have nodes or 90degrees corners without radiuses. Would you suggest I use sweep, pad, rib, ... or what?
I am working from a wireframe with only points and lines.

 

[WolfHR]

I would suggest you do the spaceframe as assembly, with each tube as separate part. In order to do so, I'd recommend having a reference part with points and lines (so you can change and fine-tune the design, and all the tubes will adapt to changes automatically*).

As for the problem of tubes, I have used method where I extruded the profiles up to the bisecting plane in the nodes- in order to keep it tidy, if a little bit more 'complex', I used extrude, up to plane, (right click on field where plane is selected) create plane, through point and a line, select spaceframe node as a point and (right click on a field where line is selected) create line, as bisecting and then select centerlines of tubes joining in the node.

* but you must enable option 'keep link with selected object' in options (Tools>Options>Infrastructure>Part Infrastructure)

 

[loki3000]

isn't there anything in the structure workbench? it's meant to design such weldments...
here is for solidworks, it's probably similar in catia

http://help.solidworks.com/2010/Eng...R.htm?id=0df895f11d46414684a8d4ddfec5a9a9#Pg0

 

[mandalores]

Thanks for the help, it was very helpful. That was a quick way to make that plane also, very nice.

I was though afraid I had to make all these sketches and planes for every tube. It's so much faster to just sweep around line with a certain radius but then it might be tricky to get the right connections in the nodes, right?

Do you know if it's possible to use the same sketch for different extrusions in different angles etc?

 

[mandalores]

Oh that looks nice loki, don't know if there is a similar thing in CATIA. Can you do for multiple tubes as well? Like 5 tubes welded into the same node?

 

[WolfHR]

Mandalores- I used only three sketches (we had 3 types of tube in the spaceframe), and put them in reference part, using copy>paste special to part and then changing the support to the midpoint of tube centerline (also in reference part) for extrusion... It all gets imported in the tube part automatically (and is automatically updated if anything is changed in the reference part).

As for multi tube nodes, up to a certain number of tubes, one can extrude up to surface of tubes that have already been placed (when prompted to choose surface, one can right click on the placeholder and create surface join to create one surface). At one point CATIA might refuse to create joints, so one extrudes to surface that can be created and then subtracts the rest of tubes*).

* of course, then one also have to remove lump that was left inside removed tube

 

[loki3000]

go to start, mech design, structure design and look there if there is an end condition or a trim command present there...