Complex Assembly and tolerance issues

I have been recently using the rhino program to build a house structure built from custom plywood pieces to be assembeled together like a lego set. An example is a horizontal beam made from interlocking plywood pieces that connects to a corner node (also made from multiple pieces) that ties into more beams and columns and so on and so forth. Although these pieces are perfectly uniform in the computer model they will be cut from wood so tolerances for assembly and have to be taken into consideration. This makes manual assembly difficult because if a beam, floor girder, or piece of floor sheathing is off by 1/16" over a span of 60’ depending on your spacing the house could be off by a significant amount by the time it is all put together. The reality is that it will be impossible to put together because the plywood pieces will not line up. The main issue I am having is being able to place the floor girders and sheathing at an exact distance. When the placement is off I have to manually move every beam, node, and floor piece by millimeters or fractions of millimeters which is time consuming and inefficient. I was wondering if there is a way to assemble these pieces with grasshopper using center line placement or something other than manually using “onsnaps” and “ortho snaps” etc. What I need is a grasshopper script that allows me to parametrically assemble these parts and allow for easy adjustment.

Hello - Since you’re looking specifically for a GH solution (I think) I’ll shift this post over to the Grasshopper forum.


Some images would greatly help understanding your issue. I’m confused as to what’s not working? You’re mentioning allowances for your composite plywood beams to be assembled, your building assembly tolerance stack up and your model needing work to be accurate.

Manually placing girders in Rhino at a hundredth of a millimetre precision should be quite easy.

I am able to manually place parts where I need them to be using on snaps but if I have a piece that’s 18mm wide going into a slot 18.5 mm wide in the model they will not align correctly. To center the 18mm wide piece I would have to draw a line .25 mm off the slot and line up the 18mm wide piece to that new line. I need a way to link these objects to points or planes in grasshopper so I can then easily move them to any position using a number slider.