New FeatureScript: T-Slot Joints for Laser Cut Parts

lemon1324

Find it here: https://cad.onshape.com/documents/5791a167e4b03c2aa6af3b35/w/8528f1c2d733302d4632f38e/e/7eab6eb8ff7dea85b9cc6a87

Adds ability to insert T-slot joints for bolted connections in laser cut parts. To create, pick the edge face of a panel, then choose screw type. Screw length and spacing parameters will need to be set.  Feature automatically drills hole through continuous stock, so "Hole termination face" can be left empty in nearly all cases.

Currently, the feature assumes that the nut you wish to use is a standard square nut, and I only implemented sizes available from McMaster.  I'm planning to add (at minimum) the ability to use standard size hex nuts before I throw together actual documentation and finalize it for release.

If anyone has feedback on problems or improvements I'd appreciate it.

michael3424

That looks like another nice feature for folks designing parts for laser cutting.  Thanks!  It will be a few months before I have the laser but your features will be getting a good work out from me then.

to_ca

This is really good, thank you.

HALtheWise

Thanks, I've been using this feature pretty extensively for various laser cutting projects. I made some improvements, feel free to merge them in if you want.

Mainly:

• Multiple faces can be selected simultaneously in a single feature
• Selecting equal spacing when # of connectors == 1 now results in a single, centered hole.
• Angled parts now cut perpendicular to their thickness, rather than aligned with the document axis.

Diff here: https://www.diffchecker.com/tGJAecxb

lemon1324

Awesome, that's great.  I'll merge and push a new version in the next couple days.

I was pretty sure I was handling angled cases correctly since I remember testing that, but evidently not.  I'll make sure I didn't have any unpublished changes of my own.

lemon1324

Well, I broke my collarbone immediately after that, so only now got around to it since I can type again.

T-Slot Joint has been updated to V2.2, incorporating changes from @HALtheWise.  Thanks again for letting me know about the improvements.

brucebartlett

Thanks, @lemon1324, this is my favourite FS, I will look forward to the improvements. I have also had some cases where it has failed, I think this is normally on angled faces. I'll let you know if I have problems. Great work and good to see the collaboration on this one. 

brucebartlett

I just had trouble getting the laser joint to work on a little job I am working on, I think it is because the plates are sitting on compound angles.

No offsets but I am seeing big gaps on the sides all round.

nicolas_lepage

Thanx a lot for those laser-cutting features, i'm quite new when it come to making and completely new to laser cutting.

It's hard making an entire project including various other domains like electricity when your workflow must include dozens of differents features coming more often than not from differents softwares.

Thanks to your script laser-cutting is pretty much an automated 1 software workflow (save a font change on Inkscape/Illustrator).

Edit: I've been trying to use the "Sheet metal model" base feature to create a workflow for Living Hinges it's a perfect tool for it since it unfold flat the part.

It is possible to use Laser joint with finished Sheet metal parts only (but unfortunately it defeat the point of the unfolding since nothing will affect the unfold sheet after the "finished metal sheet" command) and does not like those path it create.

Here's a picture

As you can see, it kinda work some of it, but cannot follow the angle or curves.

Also, from the outside, your feature seem to be remove only and should therefore be able to do it's output on a non-finished metal sheet part.

I don't know if it's possible to cram a metal sheet as an input in your script though. If it's possible, those tap could appear on the unfolded part.

Well, i think this would be to much trouble to add on a non-shop feature really, but as makers make a good portion of onshape public, i hope when someone take a look at laser cutting, they can read through that and derive what exactly is needed.

Best regards.

lemon1324

Hey, thanks for the feedback!

Yeah, making the laser features (Laser Joint, T-Slot) able to take in-progress sheet metal models is on my to-do list, but unfortunately I've been pretty busy with schoolwork for the past few months, and sheet metal parts break many of the fundamental assumptions the features make, so I haven't figured out a good way to approach patterning the features yet.

The document here presents two test cases that I know for sure are reasonable use cases with sheet metal, but that cannot be handled by my current algorithm, even if I allow sheet metal selections.

MBartlett21

@lemon1324
It may be easier if you take account of the internal sheet metal surface body, as booleanBodies will be slow if you call it multiple times

lemon1324

@mbartlett21
So in the document I added a case for "Oblique Channel Error", where the tabs would have to be computed along an edge in the flat that is itself not straight, which makes cutting even tabs along its length more difficult. 
Now that I think about it, I should be able to get around that by only cutting tabs along straight edges of the internal surface body (i.e. either entirely cut or keep the intersecting bend volumes, and have the tabs only along straight edges of the surface body) and then apply booleanBodies to cut the matching pair.

MBartlett21

@lemon1324
The bends are actually just edges in the sheet metal internal body (except rolled bends)
If you trim the faces next to the edges, the bends should work alright (You may have to remove the bend attribute on edges with only one adjacent face: EdgeTopology.LAMINAR)