I thought I would share some additional info.
Rio can special order this handpiece.
This handpiece gives the the added advantage of being able to use
everything from your 1/8" shanks to very small drill bits and
everything in between. It also is geared for that extra power you
sometimes need at slower speeds.
"There are several Foredom micromotor kits that come with a
handpiece thatis like the Foredom #30 handpiece.
You can also special order the handpiece for use with your
H. MH-120 features extra power and a geared 3-jaw #0 chuck that
takes any size rotary accessory or drill bit with shanks up to 5/32"
(4mm) diameter. Used for deburring cast pieces, polishing, taking
down weld seams, and moderate to heavy grinding and rapid stock
removal in metal and wood. It comes with a chuck key in molded
Handpiece Specifications: length= 8-3/32" / 205.8 mm, weight=1-lb.
2-oz/ 510 grams, diameter= 1-1/64" / 26mm at chuck end, CE
Works with the same HP4-917 Control Unit that comes with Micromotor
Kits K.1070, K.1080 and K.1090."
Phillip Scott G. G. GIAGraduate Gemologist
Technical Support Specialist
Rio Grande, A Berkshire Hathaway Company