Tube Laser Part Modeling - Normal to Surface Cuts?

[ASIT859]

Hi everyone,

I searched the forums but didn't see anything that caught my eye on this topic. I'm hoping to better utilize our vendors' tube laser machine in the design of frames and components and I want to ensure that I'm modeling the parts in a way that accurately reflects their true form.

Linked below is a brief video about normal to surface cutting and how parts made this way can be quite different than if they were cut with more traditional machining or cutting processes. Does anyone know how to use SW to create accurate normal to surface cut tubular parts?

Link

thank you.

 

[3DDave]

That looks tricky to do - the edge that is making contact is what is driving the cut and can switch from the inside surface to the outside surface, or use both, as on the side faces, as seen on the rectangular tubes. On the acute angle edge the contact edge goes to the inside but on the obtuse angle edge it goes to the outside.

In the case of the bird-mouth cut for the round tube it transitions from both edges making contact at the one mid-point to only the inside making contact at what I would call the end of the beak.

Construction will be the only way - intersect the part with the mating surface and then look at the curves for inside and outside surfaces. If going 90 degrees into the material at a point on the curve can remove metal more metal than the milled or sawed cut then that is the curve to use.

The little twist at the rounds where it transition from using both inside and outside edges to either the inside or outside will be trickiest.

You should be able to use one curve as a guide curve, making a cut that is normal to the surface that curve is on, and the other surface and it's curve as the limits to the cut profile.

 

[ctopher]

Have you looked at SW weldments?

https://www.youtube.com/watch?v=EeMqToVlX_c

Chris, CSWP
SolidWorks
ctophers home

 

[ASIT859]

@3DDave and @ctopher, thank you both for responding. Normal to surface modeling for tube laser is something I've thought about off and on for the better part of year and tried a few different things - but for some reason (as it seems to always occur after hitting 'send') only now did I try using SW surface features.

With respect to the SW weldments tools, I have used those in the past, but I think all of their cuts assume some orthogonal cutting tool like a saw blade for miters and chops.

I made a simple bird's mouth cut in a round tube and it appears to be correct. I'm not totally sure how all other types of cuts and features would work but this seems to work well for now. I've attached a screen clipping showing the feature tree to see what I did.

Make outside surface, make your cuts using surface features, then thicken at the end.

For anyone else, please feel free to chime in but perhaps this works well enough.

thank you.

 

[jassco]

Hi, ASIT859:

They are doable. You will need to use surface modelling techniques, like Surface/Radiate command. In mold or cold header, designers use Radiate command to create surfaces to split molds or cold header dies.

Good luck!

Alex

 

[3DDave]

This won't work for the bevel on a rectangular tube. (Pretty sure?)

 

[jassco]

Hi, 3DDave:

With surface modelling, you can do anything you want as long as you know how to define geometries in math.

Best regards,

Alex

 

[3DDave]

Sorry jassco - I wasn't responding to you; not sure how I missed your reply. "You can do anything" is an odd response for my explanation of how to do so to begin with.

Trying again

ASIT859, (not jassco) This won't work for the bevel on a rectangular tube. (Pretty sure?)

 

[jassco]

Hi, ASIT859:

I gave it a try. I see no issue of creating normal to surface cut. You just need to create 3d sketches on surfaces of your tube. And then you create surface(s) to split the tube.

If you want to do exactly (mathematically), then you will need to know cutting paths (rotation and feed). But that would be overkill for your purpose.

Best regards,

Alex

 

[ASIT859]

@jassco,

Thank you for the trial and for giving me the tip on the 3D sketch. I think that's what's most important. I'll play around with this later on when I have a chance.

@3DDave,

I did make an attempt on square tubing using the exact method I showed for round tubing and it looked awkward - so I think that precise method won't work for square tubing or perhaps angle. I think jassco's method would work, though.

Thank you all for tips and comments!

 

[fraudster]

I believe you can specify normal cuts in sheetmetal - so, convert to sheetmetal then cut might be an option