- Dec 20, 2013
"It might ramp to 2k or 3 on a deep hole, MAYBE. But 6k? I'd have to see some real good proof of that."
Brother Spindle Accel/Decel is not 0 but pretty close at 6k rpm. I frequently set clearance plane at .050". Spindle completely stops on every hole. One major difference is Brother machines use a synchronous Internal Permanent Magnet spindle motor. Typical machining centers have high torque at low rpm and that falls off pretty rapidly to almost nothing at top rpm. The IPM motors have slightly lower peak torque at the low end but a broader torque range with more torque available at high rpms which is where most modern machining is being done. They also have more torque with less power consumption. This is why a Brother High Torque machine can drill 1.5" in steel and tap 1"-8 in steel on a 30 A breaker. Modern electric cars use IPM motors to get the most torque with maximum battery life. Brother combines the performance and responsiveness of the motor with their own proprietary Synchronized Tapping feedback which keeps the spindle synchronized to the Z axis. Think about that. You have a 10 plus horsepower high performance motor with a relatively lightweight BT30 holder that is being controlled. Other builders try to control the Z axis to match the spindle. What is the horsepower and responsiveness of the Z motor? How much weight is the Z axis motor trying to control through a ball screw and coupling? Here are a couple of videos :
Client posted this, 30 holes, 30 seconds, two taps with tool change:
Brother machines are designed and built to do this all day long for years.