• "you want about 1/10 HP to drive the axes on a mini mill, assuming your using a ball screw and will have some gear reduction." ~ Runner4404spd on CNCzone. Perhaps even this is still be too small.
• Cold Fusion on CNCzone re milling forces; "The Z axis motor doesn't need to be near as powerful as the X and Y axis. I used to run a Z axis stepper that was 1/3 the power of my X and Y motors and it worked fine."
• This motor may require a brake; if a linear slide table with a ball screw was to be used.
• Linear Positioning Table #1474 could initially be used and then later #1473 could be substituted, to get a longer movement.

Initial Perceived Requirements:

• Minimum Possible Move Distance = 100 mm
• Maximum Jog Speed = ?? Need headroom.
• Maximum Cutting Speed = 4.4'/min = 63" /min = 1"/sec. This appears to be fast for the Z-axis
• Force = 200 guesstamate N (newton), 720 guesstamate ozf (pound-force). For cutting and acceleration. Perhaps this can be less because gravity is working with the downward movement.
• Acceleration: = ?

• 102004, Table Travel: 100 mm (4")
• w/ Pittman Servo Motor ~ CNC 0029, and Duncan Electronics Encoder ~ Servomotor c/w Encoder ~ CNC_0029:. Ebay 7537525761
• This linear positioning table does not have a ball screw, therefore a brake may not be required.
• This linear positioning table may not have enough travel for filament winding the rotor hub.
• If this linear positioning table is used then the limit switches from CNC 0014 can be used on CNC 0013 on the Y-axis.

• 404XR, Table Travel: 200 mm. (7.9")
• This linear positioning table has a ball screw; Also, the movement is 5mm/rev versus the 2mm/rev of the smaller CNC 0015. Will a brake be required?
• The CNC 0017 motors have brakes. They look like NEMA 23 spacing, but the slots look smaller. 1/8" wide. Looks like the shaft is 8mm. or 5/16", not the 1/4" of NEMA 23. Perhaps the pulley can be bored out for the brake motor or replaced with the correct bore pulley.
• It appears that the Pittman motor on the linear positioning table CNC 0015 is NEMA 23. This is the required size for this linear positioning table. A couple of concerns are; the Pittman motor is only 30.3 V , and this table has a 5mm / rev. reduction whereas the table #1474 appears to have a higher reduction of 2mm / rev. One of the 5:1 planetary reducers could be used with the Pittman. This will make the speed half that of the CNC 0015, however there is no brake.
• Actually the speed will probably be greater with the CNC 0014. This is because the ball screw limited to 60 rps, not the 15 rps that CNC 0015 leadscrew is. Therefore the motor can turn at a higher rpm.

Calculations for CNC 0015:

• The motor is 1:1 with the screw.
• Units used are metric.
• Maximum screw speed is 15 rps = 900 RPM. From Parker catalog 402LN data.
• Motor no load speed is 3,702 RPM.
• The effective screw pitch is 2 mm.
• Maximum jog speed = 15 rps * 2 mm = 3 cm/sec = 1.18"/sec.
• Maximum travel is 100 mm (4").
• Total maximum travel time = 100 mm / (15 rps * 2 mm) = 3.33 seconds.
• Screw revs per unit (per mm) = 1/ effective screw pitch = 1 / 2 mm = 0.5 revs per mm
• Motor revs per unit (per mm) = screw revs per unit * N_S / N_M = 0.5 revs per mm * 1 = 0.5 revs per mm

• Screw:
• Metric M5. Pitch (screw lead) (s) of 2 mm (0.2 cm) (0.002 m). 5 revolution / cm.
• Rotational jog speed =

• Direct drive ~ no additional reduction.
• Catch-up is described in article of which I have hard copy. Perhaps this 'head-room' comes from the speed between cutting and jogging?

• Not done yet.
• Maximum acceleration = 9800 mm/sec² , From Parker catalog 402LN data.

• Thread (η) = 0.3. From Parker catalog 402LN data.

• The fact that this is a conventional screw thread may negate much of the concern about the Force of Gravity. ~ DBJ
• Carriage weight = 0.06 kg
• Additional weight = 8 kg guesstamate
• F_g = 9.81 * mass (in kg) = 9.81 * 8.06 = 79.1 Newtons (N)

• = Force [F_g] * (Screw lead [m] / (2 * 3.1428)) * (1 / Screw efficiency (η))
• = (79.1 N) * (0.002 / (2 * 3.1428)) * (1 / 0.3 [η])
• = 0.084 Nm

• Motor:

• Encoder:
• The current encoder appears to have too many wires to be an incremental encoder.
• The current encoder is a Duncan Electronics BEI Model MX 2-3-25-1000-G
• The effective screw pitch is 2 mm.
• It was suggested that the minimum movement [What is the actual name for this?] should be 0.0001"; which is 0.00254 mm.
• Therefore the quadratic encoder must output a minimum of 2 / 0.00254 = 787 pulse per revolution.
• xx
• Related Miscellaneous Note:
• The controller must generate 3.000 RPM * 800 PPR / (60 sec / min) = 40,000 pulses per second. On a 1GHz PC, Mach3 can generate 35,000 pulses per second. On a faster PC, Mach3 can generate 45,000 pulses per second. (see Mach3, section 5.2.2). However the video does not appear to recommend exceeding the base pulse rate.
• The Gecko G320 and G 340 have a 25 kHz PWM frequency.
• The Gecko G320 and G 340 have a 250 kHz maximum step rate.
• Application Engineering on Screws; http://www.roton.com/web/application.jsp

Calculations for CNC 0014:

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