[Joe G.]

Looks good! Definitely see the 228 influence in this design. Some suggestions:

• Good call on the standoffs between the rails, to provide some intermediate support. Using them to double as chain tensioners would be a logical next step.
  
• Any particular reason the ball shifters are up so high? Lowering them would help CoG immensely, and open up the possibility of doing a direct drive. Live, direct driven center axle with structural dead axles in the corners is a great way to do this style drive. Doing a 228 style "S" shaped inner rail can help facilitate mounting gearboxes directly to the chassis rail, although this would sacrifice the non-unique inner/outer rail pieces, which is a very nice touch to the current iteration.
  
• Related, the ball shifter mounting looks like a potential weakness. If you look at your frame from the front, you'll notice that the rectangle formed by the chassis, ball shifters, and upper cross member has a sheet metal bend at each corner. This structure will be susceptible to parallelogramming, as is any structure that puts leverage on a bend like this. A threaded cross tube like used on the kitbot would be a better alternative.
  
• The hole pattern on the flanges looks irregular and uneven in parts. One of the greatest things about sheet metal is the ability to standardize things like this, so you can mount parts readily. My team does a 1/2" spaced 5/32" hole pattern, which allows parts stamped with it to be used for #8 through holes, #10 tap holes, or 5/32" rivets, without any additional drilling.
  
• To save a bit of weight, you can go with an uneven flange on the front and back C channels, without sacrificing much structural integrity. Here's a good example.
  
• What thickness is used? 30lbs sounds a bit heavy for what's pictured, I'd bet that you could get away with a thinner gague metal, and probably more aggressive lightening as well if your sponsor has laser capability. As was highlighted in the 1114 inspired chassis thread, you can use bumpers to reinforce a chassis.
  
• Just a piece of general advice from a team that did sheet metal for the first time this season, work closely with your sheet metal sponsor to learn how you can design parts to make life easier on them. We ended up having to redo a lot of parts because the bend radii our sponsor uses was different than what we modeled.