The following application examples will help familiarize you with the charts and formulas required to determine correct spindle selection.

Application example #1
• Boring 1 7/8" diameter hole in die cast aluminum
• Rough size 1 5/8"
• Carbide inserts, 5" tool overhang from front of housing

Step 1
Determine the peripheral speed of tool (FPM), feed rate of tool (lPR) and unit power factor (P) from the chart under boring, aluminum die casting and carbide tooling.
Results: 475 FPM, .020 IPR and .3 HP/in.³/min.

Step 2
Determine the depth of cut.
Results: (1.88 -1.62)÷2 = .13 in.

Step 3
Calculate the required horsepower using the boring HP formula.
Results: Boring HP = 12 x 475 FPM x .020 IPR x .13 in. x .3 HP/in.³/min.
Boring HP = 4.45

Step 4
Calculate the speed and torque required.
Results: RPM = 3.82 x (475 FPM÷1.88 in.)
RPM = 965
Torque =(4.45 HP x 63025)/965 RPM
Torque = 291 in.-lbs.

Step 5
Compare the tool overhang, hole diameter and torque to values in the spindle specification charts found in catalog 606E (4.18 MB) and follow the sizing rules.

Results:
4000 spindle
Front bearing bore 55mm > 1.88 in. (48mm)
Maximum tool overhang 5 1/8 > 5 in.
Maximum torque 1000 in.-lbs. > 291 in.-lbs.

3500 spindle
Front bearing bore 45mm < 1.88 in. (48mm)
Maximum tool overhang 3 7/8 < 5 in. maximum
torque 527 in.-lbs. > 291 in.-lbs.
By comparing the results, model 14000C-X1 M-BR would be the spindle of choice.

Application example #2
• Face mill a 2 1/2" wide, 1/8" deep pad in 225 BHN steel with a 4" diameter 6-tooth carbide insert cutter

Step 1
Determine the peripheral speed of tool (FPM), feed rate of tool (lPT) and unit power factor (P) from the chart under milling, steel medium 200-325 BHN and carbide tooling.
Results: 200 FPM, .006 IPT and 1.8 HP/in.³/min.

Step 2
Calculate the speed of tool in RPM
Results: RPM = 3.82 x (200 ft./min. ÷ 4 in.)
RPM = 191

Step 3
Calculate the feed rate of tool in in./min. (IPM)
Results: IPM = 191 rev./min. x 6 teeth x .006 in./tooth
IPM = 6.88

Step 4
Calculate the required horsepower using the milling HP formula.
Results: Milling HP = .12 in. x 2.5 in. x 6.881PM x 1.8 HP/in.³/min.
Milling HP = 3.72

Step 5
Calculate the torque requirements.
Results: Torque = (3.72 HP x 63025) ÷ 191 RPM
Torque = 1228 in.-lbs.

Step 6
Compare the speed and torque to values in the spindle specification charts found in catalog 606E (4.18 MB) and follow the sizing rules.

Results:
4000 spindle = Maximum torque 1000 in.-lbs.
5500 spindle = Maximum torque 2164 in.-lbs.

By comparing the results, model 5500B-X3M-40 would be the spindle of choice.