Joint Help

[kellings]

OK, I could use some help with joints. I think I have figured out a work around to put these two pieces together but I'm hoping there is a better way than to use the construction bodies from each of the parts. 

I want the axis of the Crossmember piece to align with the axis of the hole on the front side of the leg. And I want the cope of the Crossmember piece to be tangent to the outside face of the leg. See attached images. I faked their placement by hand to convey what I am trying to do. 

Is it even possible to assemble these two pieces using joints? The parts are designed the way they are to be manufactured on a tub cutting laser. 

Thanks,

[kellings]

One more screen shot showing the parts before they are assembled. 

[schneik-adsk]

Any particular reason you are building these bottom up and not top down? It will help me with how i answer?

[kellings]

I thought it would be easier to detail them? The leg gets an insert that gets welded in. And there will be a little stub welded on. So I thought for that purpose I would make an idividual weldment. And as you know, I'm still a little stuck in my Inventor ways. 

I was able to assemble this using the construction bodies from each part but that process was kind of a pain since you can't control the visiblilty of those objects when the parts are referenced in. 

[kellings]

This insert will get welded in on the top and the bottom, in addition to a stub that gets welded on that isn't shown. The leg is designed to be the jig for the welding process. It is made so that there really is no measuring involved and any welding shop can do the work.

[TrippyLighting]

It is possible to joint them, but the way you have structured your design is not the most efficient. 

I have created a bicycle tube frame a while ago tht shows how this canbe doe very efficiently and only requires one rigid-group joint to join all the tube pieces.

This should work well for your design. 

[TrippyLighting]

It is possible to joint them, but the way you have structured your design is not the most efficient. 

I have created a bicycle tube frame a while ago tht shows how this canbe doe very efficiently and only requires one rigid-group joint to join all the tube pieces.

This should work well for your design. 

[kellings]

Sorry for the delayed, I was traveling yesterday.

This is a project that I have first created in Inventor. When I learned Inventor I took a lot of the AutoCAD things I had done and redid them in Inventor as a learning tool. I'll be doing the same thing in Fusion. For this design, I wanted to try to make the design both ways. Bottom up first, and then top down. 

There is a specific reason I have modeled the pieces the way they were made (to match how they will be fabricated). If you want a more detailed explanation as to what that is, let me know and I can explain further. It has to do with the tube cutting laser that would be used to fabricate these pieces.

So maybe I could ask the question this way. Excluding that there are better ways to do this design, is there a way to use joints to mate the two pieces together? I would love to see how that is done. 

Thanks,

Kevin

[TrippyLighting]

If I am not beaten to it by anyone elese I'll look at it tonight and pot a screencast or assembly file, or both.

Provided of course that I find a good way to do it.

[TrippyLighting]

I've created a screencast to show how this can be done. Your sketches have almost everything that's necessary to join these two pieces.

[Phil.E]

@kellings

I logged a bug, HT Trippy, based on your Cross Member part.

Details here if you're interested.

http://forums.autodesk.com/t5/design-and-documentation/breaking-link-changes-component-bug/td-p/5792...

It appears to have been saved out of another design. Is this true? If not, I need to know how you achieved the cuts on the ends.

Do you have the other design still?  It would make a nice addition to the bug report I logged.

Thanks,

[kellings]

Hi guys. There is a pretty specific reason I modeled the parts the way I did. It has to do with the way they will be fabricated. The tube cutting laser that will be used isn't able to cut off the center axis of the part. It has to stay perpendicluar to the centerline of the part as it is making the cut. 

I was able to assemble these pieces both using the sufrace bodies and the sketches that were used to build the part. My goal was to find out if without any helper geometry (user created surfaces, sketches, work points, etc.) if these two parts could be assembled using joints. It appears the anser to that question is no.

Here is the method showing how this part was created. 

http://autode.sk/1hlPGit

[Phil.E]

Thanks for the explanation. I'm unfamiliar with that kind of fabrication so now it's clear. I've also never seen a workflow utilizing offset to zero that works. Probably the best use of offset I've seen yet.

Regards,

[TrippyLighting]

That's a nice technique to get the desired geometry!

No, I don't think there is any way to join this without the help of a sketch, but that sould be OK as you already had to have these sketches to create the geometry.

[Phil.E]

@kellings

Actually you could use an As-Built joint if you get the parts into the right position first.

What is wrong with using sketches or other helper geometry? I always consider the construction geometry in my parts to be part of the parts, same with sketches. When you load a bunch of these parts into a welding jig, what do you consider the jig other than "helper geometry"? Just curious as to your thinking here.

Thanks!

[kellings]

There is nothing wrong with it. It was just an exercise to push the limits with joints to see if there was functionality that I didn't know how to use. I am more comfortable with constraints but I like joints better.

I will build this design a few different ways to experiment with new things. I knew the geometry on the ends of these pieces was fairly complex and I thought a good example to try with joints.