HEIDENHAIN TNC 320 User Manual page 422

Setting the machine parameters
Before you start work with the TT cycles, inspect all
machine parameters defined in ProbeSettings >
CfgToolMeasurement and CfgTTRoundStylus.
The TNC uses the feed rate for probing defined in
probingFeed when measuring a tool at standstill.
When measuring a rotating tool, the TNC automatically calculates the
spindle speed and feed rate for probing.
The spindle speed is calculated as follows:
n = maxPeriphSpeedMeas / (r • 0.0063) where
n Spindle speed [rpm]
maxPeriphSpeedMeas Maximum permissible cutting speed in
m/min
r Active tool radius in mm
The feed rate for probing is calculated from:
v = meas. tolerance • n where
v Feed rate for probing in mm/min
Measuring tolerance Measuring tolerance [mm], depending on
maxPeriphSpeedMeas
n Speed [1/min]
probingFeedCalc determines the calculation of the probing feed rate:
probingFeedCalc = ConstantTolerance:
The measuring tolerance remains constant regardless of the tool
radius. With very large tools, however, the feed rate for probing is
reduced to zero. The smaller you set the maximum permissible
rotational speed (maxPeriphSpeedMeas) and the permissible tolerance
(measureTolerance1), the sooner you will encounter this effect.
probingFeedCalc = VariableTolerance:
The measuring tolerance is adjusted relative to the size of the tool
radius. This ensures a sufficient feed rate for probing even with large
tool radii. The TNC adjusts the measuring tolerance according to the
following table:
Tool radius
Up to 30 mm
30 to 60 mm
60 to 90 mm
90 to 120 mm
422
Measuring tolerance
measureTolerance1
2 • measureTolerance1
3 • measureTolerance1
4 • measureTolerance1
Touch Probe Cycles: Automatic Tool Measurement