503 posts · page 32 of 42.
I and J are the distance from the arc's start point to its center: I = center X minus start X, J = center Y minus start Y. Two worked examples and a self-check.
The operator-to-programmer path runs through four stages: code literacy, setup work, supervised program edits, then writing and CAM. Here is the roadmap.
A CNC program is read one block at a time, top to bottom. Here is how to decode each line of a real program, the letters that matter, and how to get fluent.
The core M-codes are identical on lathes and mills, so learn them once. The real difference to remember is the tool change: M06 on a mill, the T word on a lathe.
Two anchors end the lathe axis confusion: Z is always the spindle axis on every machine, and X is the diameter. Here is why the mix-up happens and the fix.
Line-skipping happens because programs look visually uniform and eyes lose anchor. Physical tracking, narration, and instant code recall end it reliably.
Hurco's WinMax runs conversational and NC programs side by side, but there is no magic convert button. The move is a skills translation, mapped here.
M09 turns the coolant off, closing the M07 mist and M08 flood pair. Here is the family pattern that makes it stick, plus the drill that ends the forgetting.
Interactive CNC lessons beat passive ones because apprentices learn by doing and testing, not watching. Here is what makes a lesson interactive and why it sticks.
Learn G-code first in most cases: it transfers everywhere and makes every conversational system easier. Learn conversational first only for this week's machine.
A boring bar hits the back of the part when the Z depth runs too far: wrong depth, wrong Z zero, an absolute mix-up, or a bad retract. Here are the causes and fixes.
G71 roughs with passes along Z for shafts and long profiles, G72 roughs with passes along X for faces. Here is how each cycle works and which to pick.