For building a solid frame using swerve drive, what dimensions of aluminum box tubing is most widely used/ most ideal?
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2in x 1in
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the stuff from rev?
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There are really 3 widely used sources of 2x1 tubing. Rev, Vex, and various local sources. With the local sources, it’s typically just plain box tube, with no pre-drilled holes. It’s probably a little cheaper, as you don’t have to pay for shipping and there’s a little less machining done on it before purchase. Rev and Vex both have pre-drilled variants, although there are differences in their pre-drilled holes (spacing and hole size) which may impact the ease with which it integrates into a given swerve module.
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I assumed, it just looked off for some reason. thanks for the input 
To be more specific, you also need to pay attention to wall thicknesses. Locally or from McMaster, we have been able to find .125, .063, and once, .100 wall 1x2 tubing. VEX offers .100 and .050 walls ( with .17 holes on 1” spacing). And REV offers a .040 wall and .125” on the 2” sides and .040 on the 1” sides (.20” holes on .5” spacing). Rev tubing also has internal gusset if that adds some strength.
My advice to anyone who has questions about drive base frames, is to use at least .100” wall tubing for the outer tubes. Sometimes thinner is fine, but that is highly dependent on the frame design. It’s also worth noting that some teams have had problems with the REV thick wall tubing “unzipping” along the holes in the 1” side due to the thinner wall, the holes, and a groove in the extrusion. I believe REV is removing the groove, but I’m not sure.
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Also worth noting that the “extra” weight gained from thicker walls in the drive base is very CoG friendly. These days teams build pretty lightweight bots, and teams that go for thinner tubes in the drivetrain often bolt weights rights next to them, which is a bit ironic in my eyes
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Thinner tubes have more room inside to fill with steel bolts… /j
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This. I can never really seeing our team not using 1/8in wall tube for our drivetrain at all in the near future. The odds we need that weight somewhere else is very low (and probably means we have other issues)
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Talking about 2910’s solid brass bar stock they used as part of their frame this year? That was some expensive counter weight in my opinion
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Cost a little more, but it’s worth it.
BONUS: It won’t rust (preparation for water game).
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I think he’s referring to the fact hat 2767 uses thin wall 1/2 x 1/2 steel tube.
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He is referring to the fact that we (2767) use chromoly steel as our frame. We have since 2019.
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Correct.
I was informed this was a form of trolling, so I had to.
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Pay attention to the alloy and use 6061 tubing.
6063 tubing is easier to get, but is much more likely to bend.
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When Mark perfects plywood, say somewhere around Gen6, I suppose Stryke Force will use it for swerve frames.
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I remember talking to Jack about this at states but have since forgotten. What flavor (of chromoly) and why?
First and foremost, to the OP:
1x2 aluminum is the cheapest and easiest way to go especially with today’s modern, COTs, corner bracket style swerve. My vote is a wall thickness of at least .100".
6061, Yeah!
6063, Meh,
3000, NO!
As far as our ongoing chrome moly experiment, we started with 4130 1/2 x /1/2 x .035" square tube built in a truss (there are pics of our 2020 frame somewhere in CD land). This was very stiff yet would flex a farther distance than aluminum without yielding. As you can imagine, it wasn’t fun to build. This year we used 1/2 x 1 x .035" and later on switched to .049". It was used similar to how you would use 1 x 2 aluminum however it was laid down (1" was horizontal) and welded. The swerves were screwed in the corners like the COTs swerves. We then fastened the bellypan to the midpoints of the frame. This made an “A” arm holding the module in which the hope was we would get some spring/suspension action from it.
Did it work?
According to our scales (we measure corner weight), the frame was not nearly as susceptible to the frame being “not so flat/tweaked”. This made some of our mentors happy since they get crazy if one of the wheels is lighter than the rest. Frankly, I believe running COTs modules bolted in kinda loosey, goosey would accomplish the same thing. There was some anecdotal evidence that we were less susceptible to G shocks when running over the bump, but we never tested or proved this.
Sorry Sam, I jumped ahead of you 
I almost forgot the why. In short:
We are a welding team.
Chrome moly is springier than aluminum.
They don’t build race cars out of aluminum tubing for a reason.
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