No Rest For the Studious: The Story of the University of Delaware BHR14 (Part 2)


This massive steel table was made specifically to build SAE cars.  Here, Doug and Steve lay down the first tubes of the floor.  These tubes will go right under the driver’s butt.  Each tube was tack welded with a MIG welder.  We did this because MIG tacking is quick and easy and takes very little skill.  This also kept the TIG freed up so I could weld one thing, while someone else could tack a piece together elsewhere.  When you have a month and a half to build a rolling chassis, every little time saver counts
Only two tubes on the entire car had to be bent and both were roll hoops.  Once we had our main roll hoop bent, chassis masterminds Steve and Sharnita checked it with the 2013 car.  Looks like our new design will be just as low as we had hoped.  The roll hoops are the heaviest tubes in the car (SAE mandates a 0.095” wall thickness for 1” roll bar tubes), so making them as small as possible will save a ton of weight.  Shortening this one rollbar probably saved a solid pound.  Every ounce counts!
The floor was welded together in a marathon evening.  I think I spent something like 6 straight hours hunched over with the welding torch to get this done. 
I swear this isn’t our fault!  Some experiment went wrong and caused a backup in the chem lab, flooding this loading dock at the bottom of the hill behind our workshop.  It turned out to just be water dyed green, but it made quite a mess!  Yes, that dumpster is floating.  This has nothing to do with building a racecar, but it’s too weird and funny not to share.  It also happened on the night we were welding the floor.
With the floor fully welded, we began to build in the third dimension, starting with the roll hoops and bulkhead.  Notice how the front rollhoop is canted forward a few degrees?  This was done to make the driver’s compartment a bit larger without hurting chassis rigidity too much.  It also makes the roll hoop supports a bit shorter without making the side impact tubes too much longer, shaving a bit of weight overall.  These tubes also have mandated wall thicknesses (0.065”), so again, making them as short as possible can save a lot of weight.  Anything that was not SAE mandated was 0.035” wall.  Very tough to weld, but changing to that thickness killed 10 lbs in CAD.  We’d be stupid not to try!

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