http://talk.newagtalk.com/forums/thread-view.asp?tid=337093

Thought I would share a fast and easy way to make one.

Take a piece of 3/4" copper pipe 10' long crimp one end shut which makes a nice sharp point to push into the grain. Drill a series of 1/2 inch holes up one side of the pipe. I drilled 1/2 inch holes every 4 inches apart. You could drill them further apart or all the way around or whatever works for you. One note you need to drill the 1/2 holes slowly as the soft copper wants to tear or twist  when the 1/2 bit breaks through. Scuff off the rough edges with a scotch brite pad after drilling.

Now you can use as is if you are pushing it in at an angle and keeping the holes on the bottom side, once pushed into the grain you can rotate the pipe so the holes are on the top side and you can hear grain running into the holes. When it stops pull it out and dump into bucket or whatever. Usually 2 or 3 probes is enough for a moisture sample.

If you want to be more precise or probe only certain depths you can insert a 1/2 " copper pipe into the 3/4" pipe before pushing into the grain. It's not a real tight fit but does a decent job of blocking off the 1/2" holes in the 3/4" pipe. Once you have them pushed into the grain pull the inner pipe out to unblock the holes. This way you can control where the sample is coming from. From the lower end only or the lower and middle or from the whole length.

Works pretty darn good for beans and wheat never really tried it with corn but the holes may be a little small for that.

Cheap & simple to make and very easy to push into the grain too.

Hope it helps somebody out with an idea and pictures.