hubihubi2
Bioengineer
- May 18, 2011
- 26
Hi All,
I am the beginner in milling.
I have to calculate the spindle speed and feed rate for machining special material called Macor (machinable ceramic).
The producer of Macor recommends the following machining parameters:
Cutting speed . . . . . 20-35sfm (6.1-10.7m/min)
Chip load . . . . . . . .002ipt (0.05mm per tooth)
Depth of cut . . . . . . 150-. 200in. (0.38-0.51cm)
I have to convert those parameters to spindle speed [RPM] and to cut feed [mm/min].
I have already calculated the spindle speed according to the following formula:
1. I know from above that recommended cutting speed is in range 6.1-10.7m/min. I would choose middle value, i.e. 8.5m/min,
2. I multiply cutting speed by 1000 = 8500,
3. I multiply tool diameter (e.g. 10mm) by Pi = 31.415 ,
4. Then 8500/31.415 = 270.6[RPM].
Cut feed was calculated as follows:
1. The example tool is flat mill 10mm (diameter), with four flutes,
2. Cut feed [mm/min]= spindle speed RPM x chip load[mm per tooth] x no of flutes,
Cut feed [mm/min]= 270.6RPM x 0.05[mm per tooth] x 4 = 54.12 [mm/min].
I would like to ask whether those calculations are correct?
The feed rate is very slow.
I am the beginner in milling.
I have to calculate the spindle speed and feed rate for machining special material called Macor (machinable ceramic).
The producer of Macor recommends the following machining parameters:
Cutting speed . . . . . 20-35sfm (6.1-10.7m/min)
Chip load . . . . . . . .002ipt (0.05mm per tooth)
Depth of cut . . . . . . 150-. 200in. (0.38-0.51cm)
I have to convert those parameters to spindle speed [RPM] and to cut feed [mm/min].
I have already calculated the spindle speed according to the following formula:
1. I know from above that recommended cutting speed is in range 6.1-10.7m/min. I would choose middle value, i.e. 8.5m/min,
2. I multiply cutting speed by 1000 = 8500,
3. I multiply tool diameter (e.g. 10mm) by Pi = 31.415 ,
4. Then 8500/31.415 = 270.6[RPM].
Cut feed was calculated as follows:
1. The example tool is flat mill 10mm (diameter), with four flutes,
2. Cut feed [mm/min]= spindle speed RPM x chip load[mm per tooth] x no of flutes,
Cut feed [mm/min]= 270.6RPM x 0.05[mm per tooth] x 4 = 54.12 [mm/min].
I would like to ask whether those calculations are correct?
The feed rate is very slow.