Trouble joining

I am having so much trouble trying to join a lid on my box project. All the edges are touching but it keeps sayin ‘unable to join’.
box.3dm (2.2 MB)

You’re trying to Join closed Extrusions.
Clearly, you’re brand new to Rhino.

I’d suggest running a few tutorials from the Learn page:

Have fun with it.

You could select all 5 extrusions, use Boolean Union, then MergeAllCoplanarFaces, but you wouldn’t understand what was happening and probably wouldn’t learn anything useful at this stage.

1 Like

does anyone know how to join them without having to teach myself I’ve been doing this for a long Tim

select your model and boolean union.

then run MergeAllCoplanarFaces

but do run through at least the level one info john sent. you will get where you want to go a lot faster if you slow down a bit now and take the time to learn the basics.


If it hasn’t been with Rhino that should give you a good basis for learning Rhino quickly, but Rhino approaches several things differently from most CAD programs and so requires a different mental concept and developing a familiarity with the commands to attain results you are already very familiar with. We all had to go through it. It should be quick and easy for you using the tutorials.

Another useful tool is the interactive help feature. If you open the help tab then each time you select a command it will show a brief summary of that command with a short demo. If you spend some time just selecting commands from the menu or icons you will quickly get familiar with the way Rhino works.

You can also just open the help and read it.

you would be quite amazed, but i had a structural engineering teacher specialized in using rhino as a tool for explaining in higher clases also analyzing with grasshopper, and he would forget some simple principles of rhino, which to be fair one might never use at his point and can get lost in space…

@Addie i think you meant to join the curves next to it… if i am correct, i see you already partially have joined them the wrong way so select them first and explode them then loft these 2 curves, you can disregard the side curves. complete all sides and join the surfaces, use cap.