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### Question #: 3447

Question: HOW CAN I KNOW MUCH WEIGHT MY MOTOR CARRY?

Current Solution

There are two main questions that we can answer with respect to motor torque and the mechanical advantage of lead screws, 1) What torque motor do you need to lift a particular weight, or 2) What maximum weight will my motor torque be able to lift.

This formula uses Newtons (N) as it's final unit. Use this with the included radius (R) to determine the torque. Newtons can easily be converted to lbs or ounces using online conversions.

Effort = Sf + (Load/(2 x pi x (R/p) x Se))

where:
p = pitch of the screw
Se = screw efficiency = Standard lead screw will be between 20% (.2) and 40% (.4)
Sf = static force. This is the force that is needed to start the movement. The number may be eliminated, but it is good to use a number in the 5 N to 20 N range.
Load = the expected load that the effort will need to carry (i.e., the router and the included axis assembly that the motor will need to lift)

This formula is based on the "law of the machine"

The final effort amount with its unit of newtons and R will be the torque. For example, if the effort comes to 100 N (newtons) and the R is .5 inches, then you can assume that the effort is 50 N-in since it would take twice the effort to turn form the one inch mark from the center of the shaft.

Example:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 13 = .08 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .08) x .2))
Effort = 5 N + (90 N / (6.28 x 12.5 x .2))
Effort = 5 N + (90 N / (15.7))
Effort = 5 N + (5.73 N)
Effort = 10.7 N = 2.4 lbs = 38.4 oz-in

I am putting the oz-in on the end because the formula considers the distance from the center of the shaft to be one inch.

Therefore, a 425 oz-in motor would be able to lift a 20.2 lb Router with its accompanying assembly. If the assembly and router is heavier, plug in the numbers and determine the effort required.

With a bit of algebra, the formula can be rewritten to find the load:

Load = (Effort - Sf) x (2 x pi x (R/p) x Se)

Another formula that does not consider friction at all:

Effort = (Load x p) / (2 x pi x R)

Lets see if we get similar results:

Effort = (20 lb x .08 inches) / (2 x 3.14 x 1)
Effort = 1.6 / 6.28 = .255 lbs = 4.08 oz-in

The results from both formulas appear to be very small because a 13 TPI screw will have enormous mechanical advantage.

It is evident that the first formula that does consider friction that we are loosely estimating is far more conservative than the second formula. Either way, even the most conservative formula shows that the 425 oz-in motor will handle very large weights. If you are using a lead screw with only two turns per inch, .5 inch pitch, you can determine the requirements with the first formula.

Example for a 10 TPI 5 start (2 turns per inch) lead screw:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 2 = .5 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .5) x .2))
Effort = 5 N + (90 N / (6.28 x 2 x .2))
Effort = 5 N + (90 N / (2.512))
Effort = 5 N + (35.83 N)
Effort = 40.828 N = 9.18 lbs = 146.88 oz-in

Customer Response:
thank you so much

how do i calculate torque of stepper motor if lead screw coupled to motor shaft and load applied by lead screw on plate is 100 kg by vertically

Pls

1m 16mmdiameter ball screws calculations

What is the max load that 2 NEMA 17 stepper motors (spaced 2 feet apart, both will be pushing up on the same gantry) can lift while using a rod with the following specifications T8 OD 8mm Pitch 2mm Lead 4mm for each motor.

1

Respond:

### Other Possible Solutions to this Question

• I received the electronics for book build cnc machine. I need to know how much weight the z-axis motor can hold since my (craftsman) router seems to be heavy. It is 2HP with variable speed

The motor is helped by the mechanical leverage of the screw. The 425 oz-in motors that are included in the standard electronics combo has very high torque for that type of machine. You will have no problem using that motor for the book machine.

We use that motor for very heavy spindles on the blackToe and blackFoot CNC Machine kits.

You will need to do the mechanical leverage calculation along with the torque of the motor to determine the actual weight it will lift. The calculation will need to consider the type and pitch of the screw and it would also consider the gravity constant of 9.8 m/s/s.

If you need me to determine this formula and work out the calculation based on the screw you are using, please let me know.

thank you for the reply. I would be really good to know the calculation. The lead screw is 1/2" diameter with 13 TPI. Please provide the calculation. And one more question. If I am cutting 18mm MDF with 6mm cutting bit (so 6mm pass), what can be the maximum speed rate of cutting and spindle speed of router?
thank you

I received the electronics for book build cnc machine. I need to know how much weight the z-axis motor can hold since my (craftsman) router seems to be heavy. It is 2HP with variable speed

• How can i calculate how much can carry my stepper motor? i have these informations: (Detent Torque: 2.2N.cm; Rotor Inertia: 54g.cm2; Holding Torque: 40N.cm). It's a nema 17

The holding torque will provide the best information for the calculation on how much your stepper motor will carry. But first, when you say carry, do you mean how much weight it can lift, how much inertia it can withstand during an acceleration and deceleration state or how fast it can accelerate or velocity it can maintain under load from the milling process?

How can i calculate how much can carry my stepper motor? i have these informations: (Detent Torque: 2.2N.cm; Rotor Inertia: 54g.cm2; Holding Torque: 40N.cm). It's a nema 17

• How can i calculate how much can carry my stepper motor? i have these informations: (Detent Torque: 2.2N.cm; Rotor Inertia: 54g.cm2; Holding Torque: 40N.cm). It's a nema 17

The holding torque will provide the best information for the calculation on how much your stepper motor will carry. But first, when you say carry, do you mean how much weight it can lift, how much inertia it can withstand during an acceleration and deceleration state or how fast it can accelerate or velocity it can maintain under load from the milling process?

How can i calculate how much can carry my stepper motor? i have these informations: (Detent Torque: 2.2N.cm; Rotor Inertia: 54g.cm2; Holding Torque: 40N.cm). It's a nema 17

• What maximum weight will my motor torque be able to lift? Effort = Sf + (Load/(2 x pi x (R/p) x Se)) In this formula, is Sf (static force) include gravity? how much usually is static force? can you please give one example to calculate max. weight Z-axis can carry?

There are two main questions that we can answer with respect to motor torque and the mechanical advantage of lead screws, 1) What torque motor do you need to lift a particular weight, or 2) What maximum weight will my motor torque be able to lift.

This formula uses Newtons (N) as it's final unit. Use this with the included radius (R) to determine the torque. Newtons can easily be converted to lbs or ounces using online conversions.

Effort = Sf + (Load/(2 x pi x (R/p) x Se))

where:
p = pitch of the screw
Se = screw efficiency = Standard lead screw will be between 20% (.2) and 40% (.4)
Sf = static force. This is the force that is needed to start the movement. The number may be eliminated, but it is good to use a number in the 5 N to 20 N range.
Load = the expected load that the effort will need to carry (i.e., the router and the included axis assembly that the motor will need to lift)

This formula is based on the "law of the machine"

The final effort amount with its unit of newtons and R will be the torque. For example, if the effort comes to 100 N (newtons) and the R is .5 inches, then you can assume that the effort is 50 N-in since it would take twice the effort to turn form the one inch mark from the center of the shaft.

Example:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 13 = .08 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .08) x .2))
Effort = 5 N + (90 N / (6.28 x 12.5 x .2))
Effort = 5 N + (90 N / (15.7))
Effort = 5 N + (5.73 N)
Effort = 10.7 N = 2.4 lbs = 38.4 oz-in

I am putting the oz-in on the end because the formula considers the distance from the center of the shaft to be one inch.

Therefore, a 425 oz-in motor would be able to lift a 20.2 lb Router with its accompanying assembly. If the assembly and router is heavier, plug in the numbers and determine the effort required.

With a bit of algebra, the formula can be rewritten to find the load:

Load = (Effort - Sf) x (2 x pi x (R/p) x Se)

Another formula that does not consider friction at all:

Effort = (Load x p) / (2 x pi x R)

Lets see if we get similar results:

Effort = (20 lb x .08 inches) / (2 x 3.14 x 1)
Effort = 1.6 / 6.28 = .255 lbs = 4.08 oz-in

The results from both formulas appear to be very small because a 13 TPI screw will have enormous mechanical advantage.

It is evident that the first formula that does consider friction that we are loosely estimating is far more conservative than the second formula. Either way, even the most conservative formula shows that the 425 oz-in motor will handle very large weights. If you are using a lead screw with only two turns per inch, .5 inch pitch, you can determine the requirements with the first formula.

Example for a 10 TPI 5 start (2 turns per inch) lead screw:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 2 = .5 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .5) x .2))
Effort = 5 N + (90 N / (6.28 x 2 x .2))
Effort = 5 N + (90 N / (2.512))
Effort = 5 N + (35.83 N)
Effort = 40.828 N = 9.18 lbs = 146.88 oz-in

Customer Response:
thank you so much

how do i calculate torque of stepper motor if lead screw coupled to motor shaft and load applied by lead screw on plate is 100 kg by vertically

Pls

1m 16mmdiameter ball screws calculations

What is the max load that 2 NEMA 17 stepper motors (spaced 2 feet apart, both will be pushing up on the same gantry) can lift while using a rod with the following specifications T8 OD 8mm Pitch 2mm Lead 4mm for each motor.

1

• How can I connect my pc to my motor drivers and motors?

All you need is a CNC controller like the following options:

https://www.buildyourcnc.com/item/electronicsAndMotors-electronic-component-breakout-Mach3-USB-Board

This controller is easy to connect using standard wire screw terminals and works with the mach3 control software.

https://www.buildyourcnc.com/item/electronicsAndMotors-electronic-component-breakout-Mach4-mach3-USB-ethernet-Board

This controller is a little bit more difficult to connect, but is a more feature-rich controller and will work with both mach3 and mach4 CNC control software titles.

Specifically, a CNC controller connects to the computer via a USB cable and connects to the motor drivers. These controllers also connect to the limit switches, spindle/router control, air/fluid/mist control, etc.

How can I connect my pc to my motor drivers and motors?

• HOW MUCH MOTOR CABLE DO I NEED FOR A BLACKFOOT

The blackfoot requires a total of 50 feet of cable.

The X axis needs 15 feet
The Y axis needs 17 feet
and the Z-axis needs 18 feet

These are 20 gauge 4 conductor cable.

HOW MUCH MOTOR CABLE DO I NEED FOR A BLACKFOOT

• [575] How many Amps can the output handle? My SGR pulls 2.6 Amps so I need to know if the output can handle that much.

The Mach3 USB Interface Board is designed to handle an output current of 50mA. These outputs are generally not suitable for heavy loads like Spindle Governor Relays (SGRs)​​. Given that your SGR pulls 2.6 Amps, it exceeds the capacity of the Mach3 USB Interface Board's output. Therefore, directly switching the SGR using the Mach3 USB Interface Board is not advisable. Instead, using your existing C36 rev1.1 board as an intermediary would be the recommended approach. This board can handle higher currents and will act as a buffer, protecting the Mach3 USB Interface Board from being overwhelmed by the higher current demand of your SGR.

[575] How many Amps can the output handle? My SGR pulls 2.6 Amps so I need to know if the output can handle that much.

• HOW DO I DETERMINE THE AMOUNT OF SCREW WEIGTH THAT MY MOTOR CAN HANDLE

There are two main questions that we can answer with respect to motor torque and the mechanical advantage of lead screws, 1) What torque motor do you need to lift a particular weight, or 2) What maximum weight will my motor torque be able to lift.

This formula uses Newtons (N) as it's final unit. Use this with the included radius (R) to determine the torque. Newtons can easily be converted to lbs or ounces using online conversions.

Effort = Sf + (Load/(2 x pi x (R/p) x Se))

where:
p = pitch of the screw
Se = screw efficiency = Standard lead screw will be between 20% (.2) and 40% (.4)
Sf = static force. This is the force that is needed to start the movement. The number may be eliminated, but it is good to use a number in the 5 N to 20 N range.
Load = the expected load that the effort will need to carry (i.e., the router and the included axis assembly that the motor will need to lift)

This formula is based on the "law of the machine"

The final effort amount with its unit of newtons and R will be the torque. For example, if the effort comes to 100 N (newtons) and the R is .5 inches, then you can assume that the effort is 50 N-in since it would take twice the effort to turn form the one inch mark from the center of the shaft.

Example:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 13 = .08 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .08) x .2))
Effort = 5 N + (90 N / (6.28 x 12.5 x .2))
Effort = 5 N + (90 N / (15.7))
Effort = 5 N + (5.73 N)
Effort = 10.7 N = 2.4 lbs = 38.4 oz-in

I am putting the oz-in on the end because the formula considers the distance from the center of the shaft to be one inch.

Therefore, a 425 oz-in motor would be able to lift a 20.2 lb Router with its accompanying assembly. If the assembly and router is heavier, plug in the numbers and determine the effort required.

With a bit of algebra, the formula can be rewritten to find the load:

Load = (Effort - Sf) x (2 x pi x (R/p) x Se)

Another formula that does not consider friction at all:

Effort = (Load x p) / (2 x pi x R)

Lets see if we get similar results:

Effort = (20 lb x .08 inches) / (2 x 3.14 x 1)
Effort = 1.6 / 6.28 = .255 lbs = 4.08 oz-in

The results from both formulas appear to be very small because a 13 TPI screw will have enormous mechanical advantage.

It is evident that the first formula that does consider friction that we are loosely estimating is far more conservative than the second formula. Either way, even the most conservative formula shows that the 425 oz-in motor will handle very large weights. If you are using a lead screw with only two turns per inch, .5 inch pitch, you can determine the requirements with the first formula.

Example for a 10 TPI 5 start (2 turns per inch) lead screw:

Load = 90 N (20.2 lbs)
R = 1 inch since that is the length from the center of the shaft that the motor is rated
p = 1 inch / 2 = .5 inches

Effort = 5 N + (90 N / (2 x 3.14 x (1 / .5) x .2))
Effort = 5 N + (90 N / (6.28 x 2 x .2))
Effort = 5 N + (90 N / (2.512))
Effort = 5 N + (35.83 N)
Effort = 40.828 N = 9.18 lbs = 146.88 oz-in

Customer Response:
thank you so much

how do i calculate torque of stepper motor if lead screw coupled to motor shaft and load applied by lead screw on plate is 100 kg by vertically

Pls

1m 16mmdiameter ball screws calculations

What is the max load that 2 NEMA 17 stepper motors (spaced 2 feet apart, both will be pushing up on the same gantry) can lift while using a rod with the following specifications T8 OD 8mm Pitch 2mm Lead 4mm for each motor.

1

HOW DO I DETERMINE THE AMOUNT OF SCREW WEIGTH THAT MY MOTOR CAN HANDLE

• THE BLACKTOE REQUIRES HOW MUCH MOTOR CABLE

The motor cables for the blackToe are as follows:

Total 30 feet

X - 9
Y - 10
Z - 11

THE BLACKTOE REQUIRES HOW MUCH MOTOR CABLE

• How can I determine which wires on my stepper motor bellong to A+ A- B+ or B-?

You can use a multimeter to determine the wires of the same coil (i.e A+ and A- belong to he same coil). The wires that are connected on the same coil will have relatively low resistance. A wire from one coil to another coil with have no continuity since the two coils are not touching each other.

How can I determine which wires on my stepper motor bellong to A+ A- B+ or B-?

• HOW MUCH MOTOR CABLE FOR THE BLACKFOOT?

The motor cables for the blackToe are as follows:

Total 30 feet

X - 9
Y - 10
Z - 11

HOW MUCH MOTOR CABLE FOR THE BLACKFOOT?

• HOW MUCH MOTOR CABLE SHOULD PURCHASE FOR THE BLUECHICK

The recommended total length of motor cable should be 15 feet for the blueChick v4.2

Z - 6 feet
Y - 5 feet
X- 4 feet

20 AWG 4 conductor

If your drivers will be positioned farther from the machine, you may need longer cable.

HOW MUCH MOTOR CABLE SHOULD PURCHASE FOR THE BLUECHICK

• How do I connect my motor wires to the driver?

Use the datasheet associated to the motor that you purchased. Use the bipolar parallel configuration to optimum performance. The datasheets are located in their respective motor product pages. Just click on the motion electronics at the left and scroll down to the motor you have and click on the title, or datasheet link next to the motor. The datasheet will either be in the form of a pdf, or within the instructions on that product page.

wiring diagram

How do I connect my motor wires to the driver?

• HOW DO I SET UP MY MOTOR DRIVERS?

blueChick:

X-axis
“CW230 (3.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100
Mach3 Motor Tuning: 1422.22 steps/in

Y-axis
“CW230 (3.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100
Mach3 Motor Tuning: 1422.22 steps/in

Z-axis
“CW230 (3.0A) Driver”
Set to 1/4 Microstep, 2.7A
Dipswitches: 10101100
Mach3 Motor Tuning: 1600 steps/in

blackToe:

X-axis
“CW230 (3.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100
Mach3 Motor Tuning: 1422.22 steps/in

Y-axis
“CW230 (3.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100
Mach3 Motor Tuning: 1422.22 steps/in

Z-axis
“CW230 (3.0A) Driver”
Set to 1/4 Microstep, 2.7A
Dipswitches: 10101100
Mach3 Motor Tuning: 1600 steps/in

blackFoot:

X-axis
“CW8060 (6.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100 (“0”=down, “1”=up)
Mach3 Motor Tuning: 914.29 steps/in

Y-axis
“CW230 (3.0A) Driver”
Set to 1/16 Microstep, 2.7A
Dipswitches: 11001100
Mach3 Motor Tuning: 1422.22 steps/in

Z-axis
“CW230 (3.0A) Driver”
Set to 1/4 Microstep, 2.7A
Dipswitches: 10101100
Mach3 Motor Tuning: 1600 steps/in

greenBull:

X-axis
“CW8060 (6.0A) Driver”
Set to 5.43A, 1/16 Microstep
Dipswitches: 01100110 (“0”=down, “1”=up)
Mach3 Motor Tuning: 914.29 steps/in

Y-axis
“CW8060 (6.0A) Driver”
Set to 5.43A, 1/16 Microstep
Dipswitches: 01100110
Mach3 Motor Tuning: 914.29 steps/in

Z-axis
“CW8060 (6.0A) Driver”
Set to 5.43A, 1/4 Microstep
Dipswitches: 01100100
Mach3 Motor Tuning: 1600 steps/in

HOW DO I SET UP MY MOTOR DRIVERS?

• ok I Build my CNC machine table and now need a complete set for motor and software how you can help me

Yes, I will need to know more specifics of the machine so I can recommend the correct electronics.

ok I Build my CNC machine table and now need a complete set for motor and software how you can help me

• [575] How much current can the outputs handle? I want to know if I can directly switch my SGR or if I have to go through the existing C36 rev1.1 board first.

The output current for the Mach3 USB Interface Board is 50mA. These outputs are generally not designed to handle heavy loads like Spindle Governor Relays (SGRs).

If your SGR requires a hefty current. Attempting to directly switch it using just the Mach3 USB Interface Board would not be a good idea. In that case, using your existing C36 rev1.1 board as an intermediary is the way to go. That board can handle higher currents and will act as a buffer, ensuring that the Mach3 USB Interface Board doesn't get overwhelmed.

[575] How much current can the outputs handle? I want to know if I can directly switch my SGR or if I have to go through the existing C36 rev1.1 board first.

• Can I drive my X axes with 2 motors using one motor driver?

It is not recommended to drive two stepping (stepper) motors with a single driver. The driver will need to output the sum of the current that is rated for both motors. The best way to drive two motors on the same axis, or if you need the motors to spin in a synchronous fashion, then have each motor connected to their own driver and connect the signal wires from the drivers to the same signal step and direction pin on the breakout/interface board.

Can I drive my X axes with 2 motors using one motor driver?

• CAN I USE A STEPPING MOTOR WITH AN ENCODER?

I haven't delved into using encoders with stepping motors too much. From my research, you need to have a controller that can provide the closed loop control, rather than software handling that process. I have also found from my research that using encoders on stepping motors is generally used to stop the machine in the case that the motor failed to achieve the commanded position for some reason and gives the user the chance to correct and continue with the job.

If you want proper closed loop control, it may be best to go with servos and servo controller that provide the closed loop control within the real of those two components.

CAN I USE A STEPPING MOTOR WITH AN ENCODER?

• how do I connect an 8 wire motor to a driver?

If the motor has 8 wires, you will need to wire the stepper motor in bipolar parallel. This motor (425 oz-in) is wired as follows:

Red and Blue wires to A+ on driver
Yellow and Black wires to A- on driver
White and Brown wires to B+ on driver
Orange and Green wires to B- on driver

how do I connect an 8 wire motor to a driver?

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