Front	Left	Rear

Technical Details

Carroll Bassett gave me his Bassett Metal Studios Gasoline Engine M.A.D. in 2023.

The Basset Metal Studios Gasoline M.A.D. is 400 mm. tall, 330 mm. wide, 285 mm. thick, and weighs 11100 g.

Carroll made this ascender by adapting a Harbor Freight (Central Machinery) gasoline-powered earth auger. He removed superfluous parts, and attached the engine to a 1/4" (6.35 mm.) aluminum plate. He then bolted the control grip assembly, suitably cut to size, to the side of the plate.

Carroll attached a V-pulley to the plate, and drives it with a sprocket chain connected to the auger output shaft. This V-pulley is 64 mm. in diameter with a 32 mm. minor diameter. It has 12 semicircular grooves on each side. A 60 mm. U-groove idler pulley sits above the drive pulley. Carroll mounted a CMI Large UltrAscender as a progress capture cam.

Comments

Carroll found that his M.A.D. tends to slip at the start of a climb, requiring someone to provide bottom tension until one is about 50 feet (15 m.) off the ground. He suggested that replacing the idler pulley with a driven V-pulley might solve the issue. I suggested using a shallower V angle for the main drive. We have not tested either idea.

I find that the large size and single attachment point tends to throw me off balance. I would add a second attachment for a chest harness to clip in to (similar to Nevin Davis' original MAD) to help hold me upright.

Carroll's design requires far less custom machining than Nevin Davis' original MAD.