Re: [CAD_CAM_EDM_DRO] Servo motor HP for Bridgeport

ace@... wrote:

> Hello,
> I am looking to upgrade my BOSS 3.
> Can anyone tell me the horsepower needed in a servo motor to get at
> least the same torque as the stock stepper motors?

That question can't be answered with so little info. Horsepower is
torque times speed. If low feedrates are acceptable, a low HP motor with
reduction drive will do. If you want LOTS of feedrate PLUS lots of linear
force, then you need more HP. I am using a 1/8 Hp continuous duty
rated motor on a Series I Bridgeport, and it is good up to 120 IPM or
so, able to deliver 1000 Lbs of linear force to the table. This is about
the 5/8 Hp (peak) rating point on the motor. If you want more speed,
you can just get a bigger motor (and servo amp). What you will find
is that these systems give about the same holding torque as the steppers,
but vastly outdo the steppers when moving. (Bridgeport does raise
power on the steppers when moving, which helps even out the running
torque a bit.)

If you tell me what size machine, what pitch leadscrews (should be 5 TPI)
and what belt ratio you will use, I can give you some detailed calculations
predicting performance. (I also need to know DC power supply voltage
and peak current capability of the servo amps.)

Jon