Folks,

My apologies, but there's a typographical error in Part 9. It's my mistake, and no-one else's. Rushing to meet a deadline, and thinking of two instalments at once, confused both of my brain cells.

On page 9 of issue 211, dated January 2014, in the left hand column, a few lines above fig 44, the line beginning:
“We can specify which mode we want”
should read:

“We can specify which mode we want by using the command G91.1 to set Incremental IJ mode, or by using G90.1 to set Absolute IJ mode.”

Note that the G92.1 printed in MEW is incorrect. We will meet G92 and G92.1 shortly, but those commands do something quite different to G90.1.

I realised my mistake before publication, but too late to have the copy corrected before printing, so the error has been flagged on the support website at http://www.cncintheworkshop.com from that point.

I thought it useful to repeat the note here, for anyone reading the articles but not visiting the support website.

Although annoying, the error should not cause any great practical difficulty at this stage, because the incorrect command is not used for anything in a practical program in that instalment and the examples use the (correct) G91.1 command.

While we are at it, and just in case you haven't already seen it, you should note the missing minus signs for the Z values, in Part 6. Those have been flagged for some time, in the helpful post on this Forum by John Haine (Error in CNC Article) and on the support website. Thanks, John.

Regards,

Marcus