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### Question #: 879

Question: how much weight can my stepping motor lift?

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.

Respond:

### Other Possible Solutions to this Question

• 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?

• 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 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

• 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 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.

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

• 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

• CAN THERE BE CLOSED LOOP CONTROL WITH STEPPING MOTORS?

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 THERE BE CLOSED LOOP CONTROL WITH STEPPING MOTORS?

• 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?

• HOW LONG SHOULD THE MOTOR CABLES BE FOR BLACKTOE

The motor cables for the blackToe are as follows:

Total 30 feet

X - 9
Y - 10
Z - 11

HOW LONG SHOULD THE MOTOR CABLES BE FOR BLACKTOE

• HOW HARD CAN PUSH MY BLACKTOOTH LASER?

These tubes are rated for 18mA. The power supply is able to push up to 21mA. This is a very dangerous thing to do. If you are pushing the tube beyond 18mA you will cut it's life by QUITE a bit.

HOW HARD CAN PUSH MY BLACKTOOTH LASER?

• HOW MANY STEPS PER INCH DO I SET IN MOTOR TUNING?

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

Scratch-Build / Book-Build Kit:

X-axis
“CW230 (3.0A) Driver”
Set to 1/4 Microstep, 2.7A
Dipswitches: 10101100 (“0”=down, “1”=up)
Mach3 Motor Tuning: 1600 steps/in

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

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

Scratch built/book CNC with NEMA 34 motors and CW8060 microstep driver

HOW MANY STEPS PER INCH DO I SET IN MOTOR TUNING?

• HOW MUCH MDF IS USED FOR THE BOOK MACHINE COMBO #1

Three 24" x 48" sheets of mdf is used for the book build or the combo #1 plans and kit.

HOW MUCH MDF IS USED FOR THE BOOK MACHINE COMBO #1

• BLACKTOE REQUIRED HOW MUCH CABLE

The motor cables for the blackToe are as follows:

Total 30 feet

X - 9
Y - 10
Z - 11

BLACKTOE REQUIRED HOW MUCH CABLE

• HOW LATE IN THE SEASON CAN I VACCINATE MY PATIENTS WITH INFLUENZA VACCINE?

Peak influenza activity does not generally occur until February. Providers are encouraged to continue vaccinating patients throughout the influenza season, including into the spring months (e.g., through May), as long as they have vaccine in the refrigerator and unvaccinated patients in their office.

Because influenza occurs in many areas of the world during April through September, vaccine should be given to travelers who missed vaccination in the preceding fall and winter. Another late season use of vaccine is for children younger than age 9 years who were vaccinated for the first time in the current vaccination season but failed to get their second dose. For each of these situations, vaccine can be given through the month of June since injectable influenza vaccine customarily has a June 30 expiration date.

HOW LATE IN THE SEASON CAN I VACCINATE MY PATIENTS WITH INFLUENZA VACCINE?

• HOW CAN THE ROUTER BE CONTROLLED BY COMPUTER?

The parallel breakout board has a relay that can turn the router on and off according to the control software in the computer. The router will turn on automatically prior to the machine moving (a time frame can be set so the router is up to speed). When the machine is finished and is not moving, the router automatically turns off. This is with the m3, m4, and m5 codes in the g-code.

If you are interested in the USB breakout board, you will need to get an independent relay board.

HOW CAN THE ROUTER BE CONTROLLED BY COMPUTER?

• HOW CAN YOU ENHANCE THE BLACKTOOTH LASER CUTTER?

Temperature probe monitor. Very valuable. This keeps you up to date on your coolant temperature levels.

Voltage meter. This will tell you the exact level of voltage/power you are running telling the laser to run at instead of an arbitrary mark on a drawn wheel around your POT.

Ammeter sensitive to 1mA. This will be sure your not over driving your tube and reducing it's life significantly.

Hour meter. This will tell you exactly how long your system has been 'on' giving you a more accurate bead on the length of your tubes life.

Exhaust fan upgrade. The current fan included is 100CFM. You can buy 120mm fans that push 250CFM and I have included a guide on how to go about doing this here. http://buildyourtools.com/phpBB3/viewto ... 8cdd1802bf

To push the exhaust fan even further, if you have the room/power, I would highly recommend investing in a 600+ CFM "Dust Collector" system. 250CFM is still not suffice to draw all the smoke that can come off of 3mm or 1/8 MDF cutting job.

A cutting surface. I bought myself a aluminum 'egg crate' mesh from my local HVAC company. They are used a cover for fluorescent lights and work great for low impact cutting surface. They come in 4'x8' sheets and are easily cut to fit. The other side is if you can find a steel honeycomb cutting bed to fit. These can be quite costly or fairly affordable depending where you are looking. The benefit of a steel honeycomb is you can use high power magnets to hold material down.

HOW CAN YOU ENHANCE THE BLACKTOOTH LASER CUTTER?

• HOW CAN MOUNT THE EXTRUDER TO WHITEANT

Mounting the extruder to the whiteAnt can be done a couple of ways. One is to take the 4 mounting holes located at the lower portion of the z-axis rail support and use long screws protruding out. Take a thinner material and drill the four holes matching the locations of the 4 screws and screw on nuts to hold it in place. The other option would be to use the metal bracket and fasten to the edge of the rail support.

HOW CAN MOUNT THE EXTRUDER TO WHITEANT

• HOW MANY AXES CAN MACH 3 CONTROL?

Mach 3 CNC software can do the following:

Converts a standard PC to a fully featured, 6-axis CNC controller
Allows direct import of DXF, BMP, JPG, and HPGL files through LazyCam
Visual Gcode display
Generates Gcode via LazyCam or Wizards
Fully customizable interface
Customizable M-Codes and Macros using VBscript

SET:

Spindle Speed control
Multiple relay control
Manual pulse generation
Video display of machine
Touch screen ability
Full screen eligibility

EQUIPMENT:

Lathes
Mills
Routers
Lasers
Plasma
Engravers
Gear cutting

how to wire relay with mach board. I have mach interface board with one relay

HOW MANY AXES CAN MACH 3 CONTROL?

• HOW CAN ENHANCE THE BLACKTOOTH?

Temperature probe monitor. Very valuable. This keeps you up to date on your coolant temperature levels.

Voltage meter. This will tell you the exact level of voltage/power you are running telling the laser to run at instead of an arbitrary mark on a drawn wheel around your POT.

Ammeter sensitive to 1mA. This will be sure your not over driving your tube and reducing it's life significantly.

Hour meter. This will tell you exactly how long your system has been 'on' giving you a more accurate bead on the length of your tubes life.

Exhaust fan upgrade. The current fan included is 100CFM. You can buy 120mm fans that push 250CFM and I have included a guide on how to go about doing this here. http://buildyourtools.com/phpBB3/viewto ... 8cdd1802bf

To push the exhaust fan even further, if you have the room/power, I would highly recommend investing in a 600+ CFM "Dust Collector" system. 250CFM is still not suffice to draw all the smoke that can come off of 3mm or 1/8 MDF cutting job.

A cutting surface. I bought myself a aluminum 'egg crate' mesh from my local HVAC company. They are used a cover for fluorescent lights and work great for low impact cutting surface. They come in 4'x8' sheets and are easily cut to fit. The other side is if you can find a steel honeycomb cutting bed to fit. These can be quite costly or fairly affordable depending where you are looking. The benefit of a steel honeycomb is you can use high power magnets to hold material down.

HOW CAN ENHANCE THE BLACKTOOTH?

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