Re: How does G02 & G03 work?

To those still struggling with understanding G02 and G03 commands ( as
I have been for a while now ), I had a bit of an epiphany this weekend
when it sunk into my thick skull that G02 and G03 commands do NOT cut
general curves ! They cut sections of a circle ONLY - no beziers, no
no ELLIPSES, nothing fancy at all. They cut sections of a circle.

( The true name of the command is "Circular interpolation" after all, it
it NOT "draw an arc" or "draw a curve". Why it took me so long to see
the significance of the name ...)

When looking at any of the drawings that try to explain the use of
G02/3, picture a CIRCLE. Now the values of I and J make a lot more
sense.

For example, why are I and J not SIGNED values ? How can the sign be
"inferred" by the program ? Because there is only one pair of values
( out of the four possible signed values ++, +-, -+, -- ) that, coupled
with the current position and an endpoint, could possibly describe a
section of a circle.

Hope this helps.

Alan


--

Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta