Day: June 1, 2010

Machine Shop

Sherline Tool Table

Having recently converted to EMC 2.4 and switched the tool table to the new format, I took the opportunity to add a few useful drills.

Low numbers are random end mills & suchlike. Number drills run from 100 to 180, and I’ll add more as I need ’em. Fraction drills run from 201 through 264, although it’s highly unlikely I’ll ever fit a 64/64-inch drill in a chuck that also fits in the Sherline spindle.

All the Z lengths are exactly 1, because I now have a tool length probe that is absolutely wonderful.

In practice, I use the tool table mostly to tell Axis how to draw the tool cylinder in the backplot, because I feed in most diameters directly in the G-Code. The Axis “manual toolchanger” routine prompt will now serve as a mnemonic for the actual size, but I write the G-Code to emit a (debug, #Drill_Size) message for clarity.

The  Sherline.ini file references the tool table with the line:

 TOOL_TABLE = Sherline.tbl

Herewith, Sherline.tbl:

; Common end mills
T1 P1 Z1 D0.1225    ; 1/8
T2 P2 Z1 D0.1535    ; 5/32
T3 P3 Z1 D0.187        ; 3/16
T4 P4 Z1 D0.25        ; 1/4
T5 P5 Z1 D0.3122    ; 5/16
T6 P6 Z1 D0.374        ; 3/8
T7 P7 Z1 D0.4374    ; 7/16
T8 P8 Z1 D0.4720    ; 1/2
T20 P20 Z1 D0.09787 ;  2 mm
; Number drills
T107 P107 Z1 D0.201 ;  7     5.11    10-32 clear
T109 P109 Z1 D0.196 ;  9     4.98    10-32 clear
T118 P118 Z1 D0.170 ; 18     4.32     8-32 clear
T121 P121 Z1 D0.159 ; 21     4.04    10-32 tap
T127 P127 Z1 D0.144 ; 27     3.66     6-32 clear
T129 P129 Z1 D0.136 ; 29     3.45     8-32 tap
T136 P136 Z1 D0.107 ; 36     2.72     6-32 tap
T132 P132 Z1 D0.116 ; 32     2.95     4-40 clear
T143 P143 Z1 D0.089 ; 43     2.26     4-40 tap
T141 P141 Z1 D0.096    ; 41     2.44     2-56 clear
T148 P148 Z1 D0.076 ; 48     1.93     1-72 clear
T150 P150 Z1 D0.070    ; 50     1.78     2-56 tap 0-80 clear
T152 P152 Z1 D0.064 ; 52     1.63     0-80 clear
T153 P153 Z1 D0.060 ; 53     1.52     1-72 tap
; Letter drills
T203 P203 Z1 D0.047 ;  3/64     1.2     0-80 tap

It turns out that the tool table has an undocumented limit of 50-some-odd entries, at least in EMC2 2.4.1. That puts the kibosh on my plans to add a bunch of entries to cover all the drill sizes Eagle might require for a PCB. More on that in a while …