Originally Posted by
rocketflier
Looking to do something similar. Before buying steel, I searched to see if anyone locally could do the grinding by searching "blanchard grinding <town name>". One of the first hits also does heat treatment and has large machines for either blanchard or surface grinding (72” diagonally/32" x 96" respectively). But for the size I'm also considering a brick oven and reil burner.
Not clear how you intend to attach the columns. If you make those separate, bolt-on pieces, if you find you need more height, that leaves you the option to build just those pieces later. Moving them out to support the Y axis at the ends means more work area if that's important. You can extend diagonals to the rear for more bracing of the Y axis.
I'm leaning towards rectangular tubular steel for the Y axis. I didn't see a way to fully weld the mult-tube.