grasshopper-Help for a simple half lap connection / mortise & tenon joint

Hi everyone,

I need your help, I’m learning step by step grasshopper but I can’t find any tutorial of half lap connection and mortise and tenon joint. Something very simple so parameter like length, width etc.
I just would like to understand the basic minded behind this to make it work :slight_smile:

Thank you for your help :slight_smile:

I use Rhino for my personal furniture designs.
I’ve never needed Grasshopper for that work.
Splitting, Trimming, Shrinking, Joining, maybe a Boolean here and there, and MergeCoplanarFaces has worked fine.

I think trying to learn Rhino by making up your own tutorials will be frustrating and perhaps less than efficient.
I’d suggest going through the progressive tutorials in the User’s Guide to get a good understanding of modeling with Rhino.

Have fun with it.


half (10.2 KB)


You can use the Box Slits component.


mortise (13.1 KB)


I’ve never seen that component before, can you post an example and explain how it works?

My attempts to try it give this error, which is useless to me:

  1. Box must be a clear slab, in that one dimension is clearly shorter than the other two
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Hello Joseph,

I always learn from your posts.
I tried the BoxSlits component.

There seems to be an error that it stops working depending on the thickness of the board.
It was possible to process multiple boards at the same time.

So your already posted algorithm looks better than BoxSlits. (9.3 KB)


Amazing !!! Thank you everyone for all your help, that is make more sense now for me :wink:
Hope that might help some other people as well !

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Also, check out the Reindeer plugin

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If you need more help in the future, let me know. I use Rhino/Grasshopper for Timber framing.
I would echo John Brock’s advice though. Timber Frame is a custom enough market that making Grasshopper components that are useful is a challenge. It is faster to just manually model things most times. When I first discovered Grasshopper I was so thrilled and began trying to use it for everything. Now I am a little wiser. I still am working on grasshopper projects but in a much more targeted approach.
I am a full time Timber framer/Draftsman.
We also offer drafting services, but if seems like you have that covered. :wink: :slightly_smiling_face:


i also required the same effect of a half cut of each object to insert.
i already opened this component, but I am not familiar with grasshopper.
can you please tell me how to link object in grasshopper and then get this effect


i tried it but there is an issue Can you please look at it? i uploaded a video

The Box Slits component has a Box input, not a Brep.

Therefore, I think that the combination is done, but in a Box shape.

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So any suggestion how to solve this issue.
Thank you

I can’t say exactly because I don’t have the data, but why not draw a rectangle half the length of the intersection and use Boolean operations?

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But as u see the structure have many intersection and all of them is different.
So doing it manualy and not sure it will be accurate to fit after cutting on cnc router

Can you upload the 3dm file if necessary?

Sure will do it shortly thanks.

DOME.3dm (4.2 MB)
Dear, here is the file.

Thank you for uploading the 3dm file.
Like this? (16.1 KB)

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