Critique this assembly scheme please

[Gene Davis]

This is not a question about how to do something with the software, but one of how my cabinet assembly method is schemed, and maybe can be improved.

We build the cabs and go to production sharing to source the carcase parts. Almost everything we do is with MCP, with occasional jobs done in part-plywood, some all-plywood. Joinery is lock dado with #8 x 2" assembly screws. Carcases all of 3/4" stock, including backs, and backs are inset 1/8" and "captured," with tenons all four sides. All basecab tops are two-piece, essentially one 4" strecher at front, one at rear. All stretchers are 4".

We want the 4" width parts to join to sides with a single tenon and two screws. See the pics, attached. I'm not listing the settings here, just the visuals, You can see the size of the tenon and the placement of the screws clearly and most imporantly, judge placements relative to edges, and screw-to-screw clearances. Settings place screws so none crash. You don't want a screw tip hitting another screw when assembling.

The views of a corner-join tell the whole story of our scheme. How does it look to you?

[Kerry Fullington]

Gene,

This is something similar we did for a customer (about ten years ago) so they could flat pack the cabinets.
We found that with a single tenon the two inch screws would split or swell the top stretcher in particle board core or even plywood.
The two tenons with one screw seemed to work better as well as fixing the problem with screws hitting each other.