manual programming question

[cherokeechief79]

im teaching some students how to manually program a multiflute threadmill.

I want the threadmill to feed down to the bottom of the hole ,go out to the size with comp and then do one counterclockwise circle with a z height equal to the pitch.

the pitch was 12 tpi so we went down -.5 and then did a helix up to -.4166 which worked but we shouldn't have to calculate the difference between the two.

I thought incremental would do it but the machine alarmed out and did not like this at all...….G91 G03 X0 Y0 Z.08333 J-1.

if I just use G91 G03 J-1. Z.08333 it runs fine.

I always thought I had to command an endpoint for the g03.

with a GO2 or GO3 and a circle center programmed will it always make an arc automatically right back to where it started?

 

[Colin Gilchrist]

Some Fanuc Controls will allow you to program a Full-Arc move, by just entering the "center point", and not specifying an XY Position. With some controls, the maximum you can program is a 180 degree Arc, which would be two separate G03 or G02 lines, each with a 1/2 pitch move. In the case of 2, 180 degree arcs, you would command the "endpoint" (XY) for each move. (because the endpoints are different.)

For a 360 degree arc, you only specify the Center Point. (I and/or J moves, depending on modality.)