Zuikopath, have a look at the link below[ it is actually about five threads down from your one in the list]
there is a couple of links in this thread that show hoW to make one and some further info that may be of use.
I made one yesterday in about an hour and have just finished using it for the first time. Works great. Basicially a 300 x 400 x 80 wooden box with opaque persplex cover, light source is a cheap hand held, mains source mechanics type light[ tube bulb 15 watt].
regards
CW.
(there was a url link here which no longer exists)