# Thread: Interact w/ Heidenhain 151B FeedRate Question

1. ## Interact w/ Heidenhain 151B FeedRate Question

Hello again ... I am now successfully hand-writing and posting some ISO code to my Interact Series I w/ Heidenhain 151B (yay!). Feedrate, for some reason, must always be in "mm/min" with no decimal points. Example:

%1 G70 <--Thus I'm setting it inch units
N1 G01 G90 G17 G40 X-1.0 Y-2.75 F10.0
N9999 %1 G70

OK ... so the F10.0, telling it to move at 10.0 in/min, fails. By eliminating the the decimal and all digits after, this simple code works but moves very slowly ... at an apparant 10 mm/min. However, it does move an accurate 1.0in in the X and 2.75in in the Y.

Is there some setting that overrides the imperial units for the feedrate only? Any help and suggestions are appreciated.

Thanks!

2. ## Feed Rate

The TNC 124 has only the feed rate available in mm/min regardless of imperial or metric in the x y z as far as I know

3. A feed of 10 is not 10 ipm, but 1 ipm

4. OK ... can you elaborate a bit more? Specifically, is the decimal place always moved by one digit for imperial feedrate settings? In other words, a value of 10 = 1.0ipm and 300 = 30.0ipm?

I assume that metric (program header set to G71) feedrates are as written (10 = 10 mm/min and 300 = 300 mm/min)?

Thank you for the clarification!

5. ## Feed rate

I believe, reading the manual, that the feed rate is always mm/min and that could be checked by timing a move from point a to b over two minutes. If this is the case then it would be correct that you would not program 4.2 as this would be 4.2mm/min which you would have trouble seeing the difference between 4mm/min and 4.2mm/min. I could not see any parameters to change the rapid F rate that did not have mm/min being noted.

6. ## re

I never program in metric. inch settings are always 10x programmed, the decimal is one place over.

they are not metric and will change if you change from inch to metric IIRC

this is true and scales across 5 controls I have programmed from TNC 145 to TNC 530

7. Both of you are correct. The Heidenhain manual never discusses any feedrates other than in 'mm'; however, a G70 (inch units) program does in fact move at 10.0-in/min when the feedrate is set to 'F100'. Likewise, it moves at 100-mm/min when, in a G71 (mm units) program the feedrate is set to 'F100'.

Bottom line - on a Heidenhain 151B, feedrate in inches moves the decimal over one place; i.e., 'F156' would mean a 15.6-in/min feedrate. Feedrate in mm is as read; i.e., 'F156' would mean a 156-mm/min feedrate.

8. ## Feed rates

Gus is correct, and I was wrrrrrroooooonnnnngggggg. The manual for the lower series does not say that the feed rate changes from mm to inches, but actually implies that it stays as mm. Yes I am making an excuse for the error of my thinking...... But looking at the 500 series manuals, they do note the change state from mm to inches and the terminology used (see attachment).