I had originally planned to use some 8020 3"x3" for the gantry. However, the largest piece I could source locally would only allow for 4ft of travel.
Some recent developments showed I need the ability to do 5 ft. That seems to take the 3"x3" out of consideration. I DO have long lengths of 45mmx90mm. This has previously been causing me grief because I'd align the 90mm vertically and I have CNCRouterParts stuff which doesn't seem to want to work that way. If I put the cold-rolled steel flat vertically on the 90mm side, then there's a problem because CNCRP designed the rack to sit further out, it can't be clamped onto the single slot available underneath on the 45mm side.
But, maybe I can figure a way around that somehow...? That's not my main question here, actually.
I was planning on basic routing, MAYBE some aluminum work. My question is, is a 45mmx90mm 8020 gantry actually stiff enough for this usage?
If not, I may have to simply abandon the 8020 T-slot entirely, and just get a square tube of 6061 from the local metal supplier. How that would actually work is kind of a mystery since there's almost no access for the interior, but I can probably solve that with some ridiculous nut-holding magnetic rod jig thing... I don't know, I'd just have to work that out.
It could easily be LIGHTER, at least. 8020 compromised its stiffness somewhat when it cut the slots in the walls, and more than 50% of its weight is in that interior "X" which doesn't have much to do with stiffness.
But I'd still like to use the 45mm 90mm, if it's even possible.