Sinumerik 840d radius for circle programming too small

[Anonymous]

Hello,

machine gives error: "N2497 radius for circle programming too small".
This happens during pocket operation, lead-in movement.
Post processor is latest Sinumerik 840d with enabled useArcTurn.

problematic g-code:

N2493 G1 X38.519 Y-16.174
N2495 G3 X38.598 Y-15.382 I0.079 J0.392
N2497 G2 X38.131 Y-15.382 Z18.85 I0 K-0.8
N2499 G3 X37.665 Y-15.382 Z18.7 I-0.466 K0.65
N2501 G3 X36.759 Y-15.417 I0 J-11.542

You can see there are missing lines (N2496, N2498, N2500)! I think missing code is the key to debug this error.

Dumper code:

1924: onLinear(38.51901626586914, -16.17406463623047, 19, 1060)
1925: onCircular(false, 38.597755432128906, -15.781890869140625, 19, 38.59775161743164, -15.381890296936035, 19, 1060)
  direction: CCW
  sweep: 191.353236deg
  normal: X=0 Y=0 Z=1 (XY)
  radius: 0.400001
1926: onMovement(MOVEMENT_LEAD_IN /*lead in*/)
1926: onCircular(true, 38.59775161743164, -15.381890296936035, 18.200000762939453, 38.13138198852539, -15.381897926330566, 18.850000381469727, 1060)
  direction: CW
  sweep: 35.659143deg
  normal: X=0 Y=1 Z=0 (ZX)
  radius: 0.8
  helical pitch: 0.000077
1927: onCircular(false, 37.66501235961914, -15.381905555725098, 19.5, 37.66501235961914, -15.381905555725098, 18.700000762939453, 1060)
  direction: CCW
  sweep: 35.659143deg
  normal: X=0 Y=1 Z=0 (ZX)
  radius: 0.799999
  helical pitch: 0.000077
1928: onCircular(false, 37.66518783569336, -26.92360496520996, 18.700000762939453, 36.75946044921875, -15.417498588562012, 18.700000762939453, 1060)
  direction: CCW
  sweep: 4.500006deg
  normal: X=0 Y=0 Z=1 (XY)
  radius: 11.541699

Please help me debug this problem.

[andrea.amilo · Accepted solution]

Hi @Anonymous ,

I think the issue should be related to small helical movement:

 1927: onCircular(false, 37.66501235961914, -15.381905555725098, 19.5, 37.66501235961914, -15.381905555725098, 18.700000762939453, 1060)
direction: CCW
sweep: 35.659143deg
normal: X=0 Y=1 Z=0 (ZX)
radius: 0.799999
helical pitch: 0.000077

If so, you could try to change minimum radius and/or disallow helical moves :

minimumChordLength = spatial(0.25, MM);
minimumCircularRadius = spatial(0.01, MM);
maximumCircularRadius = spatial(1000, MM);
minimumCircularSweep = toRad(0.01);
var useArcTurn = false;
maximumCircularSweep = toRad(useArcTurn ? (999 * 360) : 90); // max revolutions
allowHelicalMoves = true;
allowedCircularPlanes = undefined; // allow any circular motion

Here a list of circular interpolation settings:

I hope this helps you. Please let me know.

[Anonymous]

Thank you for your help. By changing parameter minimumCircularRadius I have managed to get suitable code.