Radial Chip Thinning Calculator (Feed Compensation for Light Radial Cuts)
The real chip thickness when the radial depth of cut is less than half the cutter diameter, and the higher feed per tooth to program so the tooth still cuts the chip you intended.
Results
The dashed line marks the value you entered.
What this tool does
When the cutter engages less than half its diameter, each tooth leaves the cut before the chip has reached the thickness set by the feed per tooth: the maximum chip is only fz × 2√[(ae/D)(1 − ae/D)]. At 10 % radial engagement the chip is just 60 % of the programmed value, at 5 % only 44 %; the tooth then rubs rather than cuts and wears sooner, which is why high-feed and trochoidal toolpaths raise the feed to compensate. At half the diameter or more there is no thinning. Stay within the feed, power and rigidity limits of the tool and the machine.
Formula
max chip thickness = fz × 2√[(ae/D)(1 − ae/D)] for ae < D/2 (else fz) · fz to program = fz wanted ÷ that factor · engagement angle = acos(1 − 2 ae ÷ D)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
dc | Cutter diameter | mm |
ae | Radial depth of cut (width of cut) | mm |
fz | Chip load per tooth you want | mm |
z | Number of teeth (flutes) | — |
n | Spindle speed | rpm |
FA | Feed per tooth to program | mm |
FC | Chip thickness ratio (actual ÷ programmed) | — |
EA | Angle the tooth is in the cut | ° |
HM | Real maximum chip thickness at the programmed feed | mm |
VP | Table feed with no compensation | mm/min |
VA | Table feed with compensation | mm/min |
Worked example
- Cutter diameter10 mm
- Radial depth of cut (width of cut)1 mm
- Chip load per tooth you want0.05 mm
- Number of teeth (flutes)4
- Spindle speed8000 rpm
- Feed per tooth to program0.0833 mm
- Chip thickness ratio (actual ÷ programmed)0.6000
- Angle the tooth is in the cut36.9 °
- Real maximum chip thickness at the programmed feed0.0300 mm
- Table feed with no compensation1600 mm/min
- Table feed with compensation2667 mm/min
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- Coverage and consumption figures vary between products. Take the values from the manufacturer's datasheet for the product you are actually using.