Decided to have another play at making the chess pieces from the original Orac instruction book ... but I now remember why I gave up with this ...

I'm running an Orac via Mach3 control, and I have 'transposed' (hand typed) the pawn piece as close as you can be from the written crib sheet from the Orac Manual into Mach3 version of G-Code. I worked out the coding and how to do the subroutines (old orac name 'Do xxx ' end 'do' etc) - and the visual representation on Mach 3 mimics nicely the drawing in the Orac brochure ... but the cut depths seem very scary as do the feed speeds.... scary enough to stall the motor on the lathe and cause me to 'whack the big red stop button'!!!

Surely the original Orac manual values are right??

Has anyone had a similar experience (or has anyone copied the official chess piece onto an Orac and made one successfully?

Yes I know I could put the outline of the chess piece into CAD and let the PC work it out for me, but half of the intended fun was hoping to see the lathe make a chess piece as it would have been when used back when it was released.

G-Code; if someone wants to try it on their machine: (Though I suggest free air cutting first!!!):

My tooling is set up as follows:

T0101 (tool 1) = 'copy tool 56deg tip (Orac manual = tool 2)

T0303 (tool 3) = 'R-H Turning tool 56deg tip (Orac manual = tool 1)

T0505 (tool 5) = 'L-H Turning tool 56deg tip (Orac manual = tool 4)

Parting off is (well would be if I got that far) by hand with a saw as I haven't yet set up the parting tool in the tool changer..

Mach3 is running in Radius mode, units of measurement = mm...

**Code:**

G18 G21 G50 G80 G90 G94 (written in radius mode) (G90=Absoloute, G91=incrimental)

(Bar stock size 25.4mm x 70mm - mild steel)

T0303

F1000

G01 X15 Z5

M03 S1500 G04 P5

G91

F1000 X-2 Z-4

M98 P1 Q4

S1200

F1000 X-0.5 Z0.2

M98 P2 Q4

F1000 X-0.98

M98 P3 Q3

F1000 Z-4.8

M98 P4 Q2

G90

F1000 X3.4 Z-0.8

F100 X4.51 Z-4.6

F1000 X3.4 Z-0.8

F1000 X2.3

F100 X4.3 Z-3.5

F1000 X2.3 Z-0.8

F1000 X0 Z-0.85

F80 G02 X4.54 Z-5.39 R-4.44

F100 G01 X3.7 Z-9.7

F1000 X4.6 Z-6

F100 X2.8 Z-9.5

F100 X6.1 Z-11.5

F100 X6.1 Z-12.7

F60 X5.1 Z-14.4

F100 X5.1 Z-25

F1000 X5.1 Z-14.4

F100 X4.1 Z-16.3

F100 X4.1 Z-22.5

F1000 X4.1 Z-16.3

F100 X3.2 Z-18

F80 X3.6 Z-22.5

F200 X4.7 Z-22.5

F100 X4.7 Z-24.5

F100 X9.2 Z-32.5

F1000 X10 Z0

F1000 X0 Z-0.5

F30 X0 Z-1.05

F100 G02 X4.34 Z-5.39 R-4.34

F100 G02 X4 Z-6.5 R-2

F100 G01 X2.5 Z-9.5

F100 X5.8 Z-11.5

F80 G02 X5.8 Z-12.5 R-2

F100 G01 X3 Z-18

S1000 G04 P5

F100 X3.5 Z-22.5

F200 X4.15 Z-22.5

F100 X4.5 Z-22.85

F100 X4.5 Z-24.5

F100 X8.9 Z-32.3

F100 X9 Z-32.6

F100 X9 Z-39

F1000 X10 Z-39

F1200 X15 Z5

S1600

T0101

F1200 X10 Z-33.5

F100 X9 Z-33.5

F25 X8.3 Z-33.5

S1000 G04 P5

F900 X10 Z-33.5

F1200 X15 Z5

S1200

T0505

F1200 X10 Z-15

F900 X5.1 Z-15

F80 X5.1 Z-12.4

F1000 X5.1 Z-15

F1000 X4.1 Z-17

F80 X4.1 Z-12.4

F1000 X4.1 Z-17

F100 X3.2 Z-18.5

F60 X2.7 Z-12.4

F1000 X3.2 Z-18.5

F60 X3 Z-18

F100 X2.5 Z-12.4

F400 X10 Z-12.4

F1200 X30 Z5

F1200 X10 Z-36.6

F80 X7.5 Z-36.6

F1200 X10

F1200 X15 Z5

M30

O1

F1000 Z-0.5

F80 X-13

F1000 X13

M99

O2

F1000 X-0.83

F100 Z-39

F1000 Z39

M99

O3

F100 Z-29.8

F1000 Z29.8

F1000 X-1 Z1.6

M99

O4

F100 Z-10.1

F1000 Z10.1

F1000 X-0.75 Z0.5

M99