I have spent several months researching worm harvesters, and looking at designs. I began construction on mine yesterday. Thanks to Bruce at wormcompostingblog.com for sharing his plans on his drill powered model.
The most expensive materials I have purchased are two plastic tubs at $12.51 each, and rolls of 1/4″ and 1/2″ galvanized hardware cloth at $17.97 and $16.97 respectively.
I have some empty syrup tubs on hand from feeding cows that I used some tin snips to cut the bottom out of that will serve as the end pieces of the tumbler. I will wrap the hardware cloth around these.
I had a 3/4″ piece of galvanized pipe that will be my center axle. The struts are 2X4 pieces cut to fit the tubs, that will stabilize the turning of the axle. I pre-drilled and attached with a lag bolt. The other pieces of galvanized pipe and 90 degree elbows I had to purchase to make the crank.
Stay tuned to see how I built the housing and rest of the Texas Worm Harvester.
Texas Jumpers 
I need to come see your worm harvester and purchase some Alabama Jumpers. Please e-mail me your location again. I know it is near the Hidden Forest Elementary. My daughter was the Principal there and now she has left and waiting on the new Ranch Elementary at 1604 and Blanco I believe. Alan
I would like to have your plan on harvester thank you
Unfortunately, the closet thing I have to a plan is on the video. My rack was built around the black catch tubs and the blue syrup buckets I used on the tumbler.
I was wondering if you completed the flow through harvester. The web shows you last working on it in February. I would be interested in if you are happy with the results of that system compaired to the tumbler.
C.Perry
I used it for several months and was pleased with it. I have moved to smaller more portable bins and separating castings with my sifter.