A friend of mine is looking at putting together a motor driven grinder and asked my opinion on the following gear reduction drive. eBay item # 270446765294 Personally I do not think a "for home use" cordless 3/8" drill or a 3/8" electric drill would work out well. I think a heavy duty 1/2" drill might work but the motor isn't designed for long running times and also do not think drills spin at high enough rpm's to hook up to a 33:1 gear reduction, I feel the grinder would be turning too slow. But I do think a 1725 rpm 1/2 HP electric motor would work; the grinder should be turning at around 52 rpm's. Ths is a tad slow but I feel it would work. I am curious what other members thoughts are and also wondering if anyone else has ever tried one of these gear reduction drives? Thanks in advance for any replys !!!