Hello,
This is cool overall, but there are a few things suggestions I’d like to make.
First: the gussets are pretty overbuilt, as are the 2x3 tubes you have between the wheels (I think you could easily get away with using 2x1x1/16).
Second: the 2x1 tubes are a good bit thicker than they need to be, plenty of teams use .1" thick tubing to great effect. I think it would be really interesting if you were to run structural analyses on the use of 2x1x.1 and 2x1x.125 “C” channel on the front and/or rear. In this application, tube may not be all that useful since the front and rear tubes aren’t having to deal with torsional forces. I saw someone in the comments suggest using 1/16" rectangular tubing, I really don’t think that’s a good idea unless you used 1/16" steel (which could be an interesting idea to test).
Third: The gearboxes are a cool design, but you do need more standoffs. You mentioned the reason for there being two was that you didn’t know where you could put additional standoffs. I think this is one of those areas where you either add standoffs or the gearbox just doesn’t work. A pair of .25" bolts just isn’t enough to hold two 2.8lbs motors. Plus, in a gearbox, things have to line up perfectly so this is an area where overbuilding is really good (to a certain extent). I might also suggest looking at ways to integrate your gearbox into the frame a bit more so you can get rid of that outer gearbox plate. Lastly, from personal experience, making a 180 degree gearbox and getting the motors out of the centre of the robot thus freeing up a good 6" is really nice.
I made some quick suggestion edits in CAD, so here that is:
https://a360.co/2WjyWOV
I have been working on a few of robot concepts over the summer partly to develop WCD chassis ideas for my team, if you have suggestions, I would love to hear them.
Artemis is a high pivot arm. Chassis and gearbox will be redesigned when I have the time:
https://a360.co/2Wx34sW
Athena is a 3-stage elevator lift concept using channel rather than tubes:
https://a360.co/30AXzYP
Hyperion is a scissor lift concept (work in progress) my team had a scissor lift back in 2018 (Spartronics 4915 2018 CAD Release - THEMIS (scissor lift)) that worked really well. Scissor lifts are great since they don’t have too many complex parts, are easy to assemble, and if designed properly, can be incredibly light:
https://a360.co/2p9k7Tc