Machine Shop people,
I am going to build a Nick-Silva-approved generic CNC, and I am planning to use some 4.724" x 4.724" aluminum extrusion to build the base. It will be 50" long and 32" wide.
Here’s the best material I’ve found so far which is $160 per 50" stick:
https://us.misumi-ec.com/vona2/detail/221005477367/?CategorySpec=unitType%3A%3A1 00000042723%3A%3Amig00000001531463&Inch=01
Here’s its cross-section:
https://drive.google.com/open?id=1xD4SxtrO_Pv-PQmDqGel3l_WvPJctdPt
Its deflection is negligible so it will make a great router.
Are there better options?
Bruce