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What is the official 3D sketch feature of Onshape?
md_ar_rahman_dip
Member Posts: 18 EDU
Answers
There are several tools in Onshape to make 3D curves. In particular, 3D fit spline and Bridging curve.
And while not technically "official" you should definitely check out Routing Curve and Control Point Curve:
https://cad.onshape.com/documents/2c2c376d9979115f9f969a08/w/0507e500181f7d6b778e86ec/e/929d02bbbb5f71c6176ac653
We also have the routing curve and control point curve tools available to help with some 3D sketch workflows as well, see forum post here https://forum.onshape.com/discussion/24874/routing-curve-control-point-curve-introduction-of-two-new-features-for-3d-curve-creation
I want to draw a line (or put 2 points or whatever in 3D) on a surface edge (which is a 3D curve) and restrict the distance between the ends of the line. How do I do this without crazy calculations and workarounds? That is usually 3D sketch or similar function in CAD programs.
Offset curve set to Euclidean should get you what you need if I am understanding correctly.
@t_e_s_t Couldn't you place a sketch on that face and use a point in the sketch and dimensions it? If not sketch on the face then on a mate connector at the end of the edge connecting the grey and orange surfaces.
If the curve is flat then yes, you can use regular sketch in a plane parallel to the plane of the curve. But how about non planar curves?
No. The curve in non planar. The MINIMAL distance between the points on the curve should be restricted. Also it would be nice to have an option to restrict the length of the non planar curve extracted from the parental non planar curve (with such function it is possiple to restring the distance between two point along the non planar curve). All these functions exist in SolidWorks and CATIA in 3D sketch.
There a no 3d sketching tool in Onshape, only standalone sketching features and custom featurescripts that cover some of it but not all, and the workflows are so much slower when using these tools. I really miss 3d sketching.
In that case. You can locate a mate connector at the point that is available and then curve pattern the MC at the specific distance along the curve to get the point you want. I'm curious how 3d sketching solves the math for you in other programs. Do you have a link to a video or something that shows that in concept.
I can not find an example of what exactly I asked, but there is a lot of powerful features in 3D sketch. Here here is a pretty close example when you can restrict the length of a spline (or even a group if different lines) in 3D Sketch when you design wiring for instance
https://www.youtube.com/shorts/toSb3B_2S6o
I saw reference of a similar request like that before. Cool feature. Only thing I can think of atm to accomplish your original ask is my suggestion with a mate connector and the pattern on curve by distance. Maybe someone else with more coffee in them might have a better idea.
It's a little ugly, but you can use a sphere to get the intersection of a known distance and an arbitrary edge. You might want to get the sphere (and other) custom features from this doc to make that process quicker:
https://cad.onshape.com/documents/a81f647d405a78c5b70bdbde/v/e4b2f9c8c9b1eb5fa8466329/e/bec98f91580bad4c70005038
Depending on what you want to do at that fixed chord distance, you might split one of the faces with the sphere. I was hoping that @EvanReese 's split edge custom feature could split an edge based on a sphere input, but as far as I can tell, it doesn't do that.
Simon Gatrall | Product Development, Engineering, Design, Onshape | Ex- IDEO, PCH, Unagi, Carbon | LinkedIn
Would this do what you need?:
https://cad.onshape.com/documents/73e589e24081d42cb1170e20/w/5aeae1a2ab7aff2a4ef21b22/e/78c6c5a09e49e918ec5a3202?renderMode=0&uiState=69b1ca0c30d7776c7c758233
Change the variable #SurfaceLength as needed to move the mate connector, and the line will follow.
Splitting an edge via chord or arc length would really be helpful. I did remember there's this custom feature "CT points" which will create points at a percentage, arc length or even (pseudo) random.
https://cad.onshape.com/documents/431001f3ab91995c47ba6ed6/v/e937a091d3c8d20034d795b4/e/170e901b21b8387245d0668e
Simon Gatrall | Product Development, Engineering, Design, Onshape | Ex- IDEO, PCH, Unagi, Carbon | LinkedIn
I forked that code awhile back and started to use it as a utilities library but was disappointed in the pseudorandom implementation they used. It turns out their definition of pseudorandom must have been something like "user selectable from a list of points" which wasn't a good fit for my OnlyTabs implementation. So I've got a more robust set of edge splitting utils baked into that code now that do both edge splitting by a percentage and by length depending on which function is being called. And slightly truer pseudorandom seeded functionality that I need to spend some attention on turning into an importable precondition for other features.
Derek Van Allen | Engineering Consultant | MeddlerCare to share?
Simon Gatrall | Product Development, Engineering, Design, Onshape | Ex- IDEO, PCH, Unagi, Carbon | LinkedIn
Here's the OnlyTabs link and a forked copy of @GregBrown's Best Fit pattern document which contains my current spacing utils functions that are being used in both OnlyTabs and Bip Joints for doing edge splitting into domain segments for those features. Doesn't yet include the RNG stuff because I'm borrowing a little bit from @EvanReese's library for the moment there, although I'll note that my implementation of the RNG function needed to be mapped to a narrower selection of possible seed inputs for UI reasons. It's all kinda chewing gum and popsicles to be honest but that just means it's prime opportunity to refactor and make it clean.
Derek Van Allen | Engineering Consultant | Meddler@S1mon you're right mine doesn't do that, but the other great one by @jelte_steur_info does. Here's an example https://cad.onshape.com/documents/15d70756831b060b08b2fdb7/w/6f1ff3b15068275ef8c3e466/e/8bfd1848839eeb79c86e2e6c
@Derek_Van_Allen_BD I think mine was a riff on one shared by Ilya a while back which also linked to a wikipedia page or something. These days a pseudo random function is the kind of well-established code thing LLMs can one-shot.
The Onsherpa | Reach peak Onshape productivity
www.theonsherpa.com
https://cad.onshape.com/documents/df7470bfcac6dbf738846c11/v/90607deb13324e6c12b5e214/e/27dcebec77fdc3f92e51e357
Here's that featurescript that can split an edge at a distance.
Man I wish it only took one shot during implementation lol. The issue ended up being some undocumented limits surrounding integer inputs in featurescript's UI that were mismatched from the general integer limits for the rest of featurescript. Kept running into overflow issues.
Derek Van Allen | Engineering Consultant | Meddler