# Create a classic "edge" with three beams

**URL:** <https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089>\
**Category:** compas\_rhino\
**Created:** [March 22, 2026, 7:15am UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089 "2026-03-22T07:15:20Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![supcha](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@supcha](https://forum.compas-framework.org/u/supcha)\
**Post date:** [March 22, 2026, 7:15am UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/1 "2026-03-22T07:15:21Z")

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first i’d like to thank you for this piece of software / environment. great work

i’m trying to use compas-timber in rhino8

when having a look at the examples i miss one type of Joint, the classic three beam edge in a “fachwerk” construction.

two horizontal beams have a L-Lap joint and the vertical beam has a tenon / mortise into them.

i suspect it need to be composed with rules and features?  
is there an example of this around?

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**Author:** ![supcha](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@supcha](https://forum.compas-framework.org/u/supcha)\
**Post date:** [March 24, 2026, 5:07am UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/2 "2026-03-24T05:07:53Z")

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here the sketch in grasshopper.

since the joints are a 3dimensional Y topology, rather than L joints (which is what the given components offer at first hand) i guess the recognition / built in hierarchy fails.

i tried adding a tenon feature to the posts, but so far i failed. (guess i also need to ad a mortise to the sills to complete what i want…

but i suspect there are better ways. if anybody could point this out for me.

 ![image](https://us1.discourse-cdn.com/flex015/uploads/compas_framework1/original/1X/2152d8ee938b670b4ce65edefe356d2f583df586.jpeg)

the result when i bake them:

 ![image](https://us1.discourse-cdn.com/flex015/uploads/compas_framework1/original/1X/fab5e47115e05e46434fe1611ca796a42f2a1b9a.jpeg)

there are no mortises in the sills (may because i didn’t explicitly add the feature). and also on edge doesnt seem to generate the lap correctly (which i don’t know why this acutally is…)

PS: i wouldn’t mind if this has to be solved with the GHpython component. in a similiar matter like the “Y topology” in the “example script beam joints” file.

but i seek advices to get started with this particular set.

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**Author:** ![chenkasirer](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.compas-framework.org/chenkasirer/32/549_2.png) [@chenkasirer](https://forum.compas-framework.org/u/chenkasirer)\
**Post date:** [March 30, 2026, 11:25am UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/3 "2026-03-30T11:25:25Z")

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Hi @supcha !

Thanks for posting.

So if I’m getting it correctly, the two base “Schwelle” beams should meet with a french ridge lap, and then the tenon of the “Pfosten” should run through a mortise in both beams, is that correct?

Not sure if this case can be automatically handled by the JointSolver just based on the Y topology, it could take some tinkering and potentially some manual joint assignment.

Any chance you can share you Rhino/GH document so that we can try some stuff out?

Thanks,

Chen

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**Author:** ![supcha](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@supcha](https://forum.compas-framework.org/u/supcha)\
**Post date:** [March 30, 2026, 6:53pm UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/4 "2026-03-30T18:53:26Z")

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thanks for your reply.

i’d gladly share the file here, but it seems i can’t upload the .gh file.  
so i uploaded it to my webserver instead.. here the link.

[https://seismic.industries/test/test\_compas\_timber.gh](https://seismic.industries/test/test_compas_timber.gh)  
(or please advise on how to share)

as the “edges” are two horizontal beams and a vertical one, this does not get recognized as it’s own category.. a flavor of a Y joint.

thanks for any hint/help on pointing out on how to solve or work around this.

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**Author:** ![supcha](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@supcha](https://forum.compas-framework.org/u/supcha)\
**Post date:** [April 1, 2026, 3:19pm UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/5 "2026-04-01T15:19:02Z")

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@chenkasirer  
i had a peek at the listed issues in the compas timber github repo.  
it seems the project is aware of this circumstance of the missing components & logic.

[https://github.com/gramaziokohler/compas\_timber/issues/687](https://github.com/gramaziokohler/compas_timber/issues/687)

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**Author:** ![supcha](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@supcha](https://forum.compas-framework.org/u/supcha)\
**Post date:** [April 18, 2026, 9:21am UTC](https://forum.compas-framework.org/t/create-a-classic-edge-with-three-beams/1089/6 "2026-04-18T09:21:44Z")

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as a follow up question to this:  
is there an estimate, if and when, more Y topology, and K topology will be supported by grasshopper components or at least by using ghpython?