It has been a very busy 30 days, but well worth the effort...

There were 4 teams at the competition on May 12th, and my machine was the only one to run the entire 30 minutes. It also moved about 75 kg of JSC-1A, 65 of it going into the collector, 10 on the ground. It also ran exactly at the specified limit of 30 watts average. Rob Mueller of NASA made the point that is the power used by a refrigerator light bulb, and it is amazing that any real work can be done with it. Even though it didn't move the minimum 150 kg to win a cash award this time, I think that it can be done.

This is one of the cases where simple was better. The machine can be described as an inverted bucket, continuous chain driven drag. The buckets are moved to the end of a 4 foot horizontal boom where they flip over and contact the soil, and drag it back towards the delivery ramp at the root of the pivot. The machine uses 3 motors driving the bucket chain mechanism, and one to pan the boom from side to side. The boom pivots vertically as the hole it digs becomes deeper. I'll have some pictures posted on a web site soon, but I'm still recovering from the last couple of weeks...

In the meantime, here are links to a couple of small avi files that show an earlier version in action during a test on some clay soil:
Front View
Back View

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