Repair time for the axle housing. Running with a flat tire over rocky terrain with an aluminum housing--not recommended so much
Pretty much tore the entire bottom section out in one fell swoop. It's probably a permanent part of the race course or got into some poor racers tire
...
Anyway, cleaned up all the edges and had to do quite a bit of grinding on the internal walls as well as the sides of the C-channel I'm using as it the channel was about 1/8th inch too wide. Pretty sure this stuff is 6061 grade or something of that nature, very difficult to grind on the flat, just doesn't want to cut. I though of splitting the channel into angles and going back-to-back down the center, leaving a protruding keel-like rib, but that would have created 8 pieces to weld into place as the sides would also have needed angles welded to them to make to the "T" in the middle.
Got it pretty well cleaned and prepped--dropping it off this afternoon at an old friend's shop for him to Tig it together.
I'm leaving enough room for a future mod ... a pair of aluminum sleeves welded into the lowest corners with a slot cut through the corner walls next to the sprocket. Put a shaft through with a wheel protruding about an inch through the slot to roll over bottom outs. Pretty much the same thought as the anti-scalp wheels on my deck mowers. In the race vid, the first spot i got stuck and and had to reverse out of was the high center around a set of deep ruts that the leading edge of the housing just dug into like a pan dozer. That course has ruts like that 2-3 feet deep in places for about 50-70 percent of its length.