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Air-Driven Mica-Miller

     The Air-Driven Mica-Miller is a popular, lightweight, rugged, and a powerful tool. This undercutter is available in two models for use with High-Speed Steel or Tungsten-Carbide saw blades.
     The 6,000 R.P.M. model, for use with solid carbide saw blades, is great for prolonged use on larger commutators. Less stopping to change blades saves you time and money.
     Uses the three interchangeable heads described below.
     Full Load saw spindle speeds at 90 lbs. air pressure are listed below:

Air-Driven Mica-Miller: For use with H.S.S. Saws For use with Tungsten-Carbide Saws
R.P.M. Catalog Number R.P.M. Catalog Number
 With "small" head, 5/16" arbor 2,500 M-MU201 ***
See Note
With "Standard" Head, 5/16"
 or 7mm. arbor
2,000 M-MU202 OR (7M) 6,000 M-MU202C OR (7M)
With "Heavy-Duty" head, 3/8" arbor 1,350 M-MU203 5,350 M-MU203C
Extra Interchangeable Heads (see descriptions below):        
"Small", 5/16" arbor M-MU01 M-MU01
"Standard", 5/16" arbor M-MU02 M-MU02
"Standard", 7mm. arbor M-MU027M M-MU027M
"Heavy-Duty", 3/8" arbor M-MU03 M-MU03
Air Hose, 10ft. long;
 complete with quick connector
Automatic Air Filter-Lubricator   FILL01   FILL01
Steel Carrying Case, No. 1;
for Air-Driven Mica-Miller
  CASE101   CASE101
    Net Wt. 3-1/2 lbs., Shipping Wt. 6 lbs.   Net Wt. 3-1/2 lbs., Shipping Wt. 6 lbs.

At 90 lbs. air pressure, Air Motor, for H.S.S. Saws develops .6 h.p. and for Tungsten-Carbide Saws develops 1.0 h.p.  Overall length 14-1/4".

If you do not already have an automatic oiler in your air-line, be sure to include one in your order ( see Other Products / Air Filter Lubricator, for description) as oil is essential in the operation of an air motor.


*** Not recommended
for use with small head
at this speed.

Interchangeable Heads for Martindale Mica-Millers

The three Martindale Mica-Millers are the results of continuous research and "on-the-job" testing in an effort to make the most serviceable all-around portable mica undercutters possible.
Three Models
This versatile tool is available with three different power sources; Model K (direct drive electric motor), Flex-Drive (flexible shaft), Air-Driven (air motor), to meet the requirements and preferences of all electric repair shops and maintenance departments.
Three Interchangeable Heads
Also available for use on any of the three models are three interchangeable heads which make it possible to use the Mica-Miller with saws or "V" cutters ranging from 23/32" diameter to 1-1/4" diameter to undercut a wide range of commutator sizes.  All three heads are equipped with depth gauges.  The two smaller ones have slot guides and the Heavy-Duty head has roller supports.  Standard and Heavy-Duty heads have ball bearing spindles.
The "Small" head allows undercutting closer to risers than has been possible before.  The "Standard" head is for all-around use, while the "Heavy-Duty" head, with its larger and more rugged parts, will withstand hard usage on larger commutators.  To change from one size head to another it is necessary only to remove one screw, change heads and replace screw.

Three Interchangeable Heads

(Left) only 1-7/8" wide (less Slot-Guide). Uses 23/32" or 3/4" diameter × 5/16" hole Saws or "V" cutters.

(Above) 2-1/4" wide
(less Slot-Guide). Available for use with 7/8" or 1" diameter × 5/16" hole, or 25 mm. diameter × 7mm. hole Saws or "V" cutters.

"Heavy-Duty" Head
(Left) 4-1/4" wide overall.  Uses 1-1/8" or 1-1/4" diameter × 3/8" hole Saws or "V" cutters.

  All Mica-Millers are light-weight, sturdy, and carefully   balanced.  These qualities give the operator immediate confidence in the tool and his ability to undercut rapidly without fatigue.
  When Undercutting, start at the riser end of the commutator and pull the tool towards you.

Saws and Cutters for Martindale Mica-Millers
(High-Speed Steel)

     The table at right lists at least 2 diameters of saws and cutters for each of the three interchangeable Mica-Miller heads.
     Saws ("U" slot) are stocked in the following thicknesses (thousandths of an inch): 15, 18, 20, 23, 25, 26, 28, 30, 32, 35, 38, 40, 43, 45,50,  53, 55, 58, 60, 63, and 65, and can be supplied in other thicknesses at a slight additional charge. (Standard metric thicknesses available.)
     V-cutters ("V" slot) are all .045" thick and are stocked with 40°, 50°, and  60°, angles between cutting edges.  40°, cutters are generally used for thin mica, 50° for medium mica, and 60° for thick mica. 

  Type Number O.D. Hole Catalog Number Catalog Number
      H.S.S. Carbide
14-HS Saws 23/32" 5/16" HSMS14 ***See Above
15-VHS Cutters 23/32" 5/16" HSMSV15 ***See Above
65-HS Saws 3/4" 5/16" HSMS65 ***See Above
65-VHS Cutters 3/4" 5/16" HSMSV65 ***See Above
75-HS Saws 7/8" 5/16" HSMS75 TUNS75
75-VHS Cutters 7/8" 5/16" HSMSV75 TUNSV75
85-HS Saws 1" 5/16" HSMS85 TUNS85
85-VHS Cutters 1" 5/16" HSMSV85 TUNSV85
25-HS Saws 25 mm. 7 mm. HSMM25  
25-VHS Cutters 25 mm. 7 mm. HSMMV25  
96-HS Saws 1-1/8" 3/8" HSMS96 TUNS96
96-VHS Cutters 1-1/8" 3/8" HSMSV96 TUNSV96
106-HS Saws 1-1/4" 3/8" HSMS106 TUNS106
106-VHS Cutters 1-1/4" 3/8" HSMSV106 TUNSV106

Steel Carrying Cases

     Heavy gauge steel carrying cases to protect your Model K, Air-Driven or Flex-Drive Mica-Miller, extra heads, saws and cutters, accessories, etc., are available.

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