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### Question #: 3547

Question: I am asking what to set my steps per using your kit stepper motors and a 1/2"x13 lead screw with Mach3

Current Solution

Here is the formula for steps/inch (steps per inch)

Steps = how many steps for a full ration of the motor = standard motor steps x number of microsteps for each step
Standard motor steps for our stepping motors is 200 steps per revolution.
Microsteps are selected on the driver and are shown as full, 1/2, 1/4, 1/8, 1/16, 1/32 etc... Use the denominator for the number of microsteps per step.

Inches = how far the travel is for one full rotation of the motor. For the 1/2" - 13 TPI (threads per inch), the travel length will be 1"/13 or .076923". So, for one revolution of the motor, the travel distance will be .076923 inches.

So, the steps = 200 * microsteps, let's make this 1/4 just for the formula.
The inches will be .076923. Plug those into the formula:
Steps / inch = (200 * 4) / .076923 This can also be written as:
200 * 4 / (1 / 13) = 10,400

Respond:

### Other Possible Solutions to this Question

• How can I decrease the rapid acceleration of the cutter from a completed cutting operation to a new location so that the stepper motor will not lose its steps and mess up the machine zero settings? I am using CamBam and Mach3 on my machine with a chain drive. what is the best way to reduce accleration

Decreasing the speed of acceleration in the cutter? Meaning of your router/spindle?, To modify the speed of a router will be going to the router itself and modifying the speed, but if a spindle is being used modifying it will be done either manually in the VFD (VFD Setup:
Change PD001 to '0' (source of run commands)
Change PD003 to 300 (main frequency - Hz)
Change PD004 to 300 (base frequency - Hz)
Change PD005 to 400 (max operating frequency - Hz)
Change PD006 to 2.5 (intermediate frequency - Hz)
Change PD008 to 220 (max voltage - V)
Change PD009 to 15 (intermediate voltage - V)
Change PD010 to 8 (minimum voltage - V)
Change PD011 to 100 (frequency lower limit - Hz)
Change PD142 to 7 (rated motor current - Amps)
Change PD143 to 2 (motor pole number)
Change PD144 to 3000 (rated motor revolution))<- make sure these are your settings in the VFD. If the spindle is wired to the breakout board and is working through Mach 3 then the modification will be done in your CamBam/Feed rate settings.

• I need the calculation to determine the stepper motor torque to find the load that it can lift using a lead screw at 1/2" diameter with 13 TPI.

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

I need the calculation to determine the stepper motor torque to find the load that it can lift using a lead screw at 1/2" diameter with 13 TPI.

• I HAVE ONE OF YOUR SMALLER STEPPER MOTORS RUNNING MY X AXIS BRIDGE CRANE AND IF IT IS MOVED TO FAST THE MOTOR SOUNDS LIKE SKIPPING STEPS WILL 651OZ REQUIRE A DIFFERENT POWER SUPPLY CONTROLER?

Yes, the 651 oz/in motor requires a driver that is compatible to the motors (the motor will draw 6 amps max and the driver paired with this motor will be able to allow for a 6 amp draw). I would also recommend a 36 volt power supply for better high velocity performance.

I HAVE ONE OF YOUR SMALLER STEPPER MOTORS RUNNING MY X AXIS BRIDGE CRANE AND IF IT IS MOVED TO FAST THE MOTOR SOUNDS LIKE SKIPPING STEPS WILL 651OZ REQUIRE A DIFFERENT POWER SUPPLY CONTROLER?

• I have your Nema 24 electronics kit and am having problems with the Z axis dropping over time. I am using a PC 8902 motor. Any ideas on what the problem is? What should be the motor tuning values in Mach3? Thanks

Make sure all your bolts/screws are tighten correctly and if using a lead screw make sure your anti-backlash nut is not offset. Now a default setting will be 10101100 for your driver dip switch settings and in motor tuning (mach3) 1600 steps per, 400.02 velocity, 4 in acceleration. now the acceleration and velocity can be adjusted to move your machine faster, but if set to high they could stall. Make sure you have the correct wiring from your motor to your driver (https://www.buildyourcnc.com/Documents/PN.SM60HT86-2008BF-U%20(inhouse%20PN.60BYGH303-13)%20(1).pdf).

• I need the calculation to determine the stepper motor torque to find the load that it can withstand in horizontal position using a lead screw at 1/2" diameter with 13 TPI.

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

I need the calculation to determine the stepper motor torque to find the load that it can withstand in horizontal position using a lead screw at 1/2" diameter with 13 TPI.

• I have theNema 24, 425 Oz stepper motors kit what are my Ports and Pins?

The ports and pins are designated by the breakout board that you have, Now here are the schematics for both(https://www.buildyourcnc.com/item/electronicsAndMotors-parallel-breakout-relay#prettyPhoto/2/ and https://www.buildyourcnc.com/item/electronicsAndMotors-electronic-component-USB-Controller-Breakout#prettyPhoto/2/) Which for the Parallel the pins will be 1,14,2,3,4,5,6,7,8,9. For 1,14 you will need to use them together for a additional axis. Setup will be (ex.mach3) step in (2) / direction pin (3). continued for other pins, 4,5 6,7 etc.
Now for the USB it has the label on the board right next to the terminal blocks, x-axis/etc.

I have theNema 24, 425 Oz stepper motors kit what are my Ports and Pins?

• I have one of your smaller stepper motors running my X AXIS bridge crane and if it is moved to fast the stepper motor sounds like it is skipping steps will the 651oz stepper motor require a different power supply and controler?

Yes, the 651 oz/in motor requires a driver that is compatible to the motors (the motor will draw 6 amps max and the driver paired with this motor will be able to allow for a 6 amp draw). I would also recommend a 36 volt power supply for better high velocity performance.

• Have checked stepper motor wires dozens of times and they are wired like diagram says. Stepper motors will not turn under power. I am using laser control option. What should I do?

This sounds like a problem with the step (pulse) signal. The driver motors receive two signals from the computer via the board -- one is high or low and tells the motors which direction to turn, one is a square wave pulsed signal(quick that tells the motor to turn or a constant high signal that tells the motor to maintain its position. With an oscilliscope you can check for proper signal at the board. If you bought the board from us, please contact us to arrange a return authorization.

Have checked stepper motor wires dozens of times and they are wired like diagram says. Stepper motors will not turn under power. I am using laser control option. What should I do?

• BUILDING ONE OF YOUR GREENBULL 6X LONG AND 2.2 KILOWATT SPINDLE DOES NOT FIT. SEEMS LEAD SCREW YOU SENT WITH KIT IS SHORT 42" LOOKS LIKE IT NEEDS TO BE 5 OR 6 INCH LONGER. THIS CORRECT? WHAT THE NEEDED LENGTH FOR UNIT?

The leadscrew length for the greenBull long Z-axis is 47 inches.

• I'm using the big 651oz in stepper motor for X and Y and the smaller 325 for the z and X and Y keep tripping when I try to tune the motors on Mach3 but Z seems to work. I have to turn power on and off to reset....is this a wiring issue?

This is most likely a wiring issue. I would disconnect all of the power to the drivers and reconnect one at a time to isolate the problem.

that was not helpful. I already did that way before submitting this question. there are not that many wires here and I have already rewired this a few times. I actually think its a software or interface board issue because it does work sometimes but then trips (possibly a amperage / voltage issue) I am using the interface board that has a parallel port and usb for 5V. are there different settings that I need to setup?

• I have an emco vmc 100 mill with a rotary head tool changer I would like to use existing stepper motors do you have a kit you would recommend?

We currently do not have an available kits for adapting other versions of electronics (motors) to our drivers, other than our complete kits including our steppers.

Use one acorn cnc product. I have one and is great

I have an emco vmc 100 mill with a rotary head tool changer I would like to use existing stepper motors do you have a kit you would recommend?

• I'm building my own machine using your motors and drivers. What is the best dip switch settings for the 3.0 amp drivers powering the 425 oz motors

The settings that you will use for your 3.0 amp driver to properly power and turn your 425 oz-in stepper motor will cheifly depend on your application and the mechanical parts you are using on your machine. In all circumstances, the amp setting for the stepper motor (according to the datasheet) should be 2.8 amps. Use the closest setting on the driver without going over.

Here is a good rule of thumb for the microstepping which will correspond to the resolution, but wil also affect torque. You always want to try to achieve the best torque and resolution for the axis you are moving but go with the lowest microstepping possible. In cases where there is mechanical advantage, like a lead screw scenario, where for each motor revolution, the axis move a very small amount, you will want a very low microstep value. This is because the mechanical configuration will provide most of the finer resolution and you will not need the microstepping to assist in this. Increase the microstepping only in conditions where the axis is not moving smooth enough, or where there is a mechanical disadvantage. A mechanical disadvantage would be where the stepper motor is causing a great amount of movement in the axis and the resolutions suffers from this condition. Increase the microstep value up to your desired resolution, but don't go over since the torque of the motor will decrease.

I'm building my own machine using your motors and drivers. What is the best dip switch settings for the 3.0 amp drivers powering the 425 oz motors

• I am going to build a CNC 4x4 plasma table. The frame is made of 1 1/4" pipe and the gantry will be made of either 2"x 2" or 2"x 3" tubing. What size stepper motors do you suggest?

We recommend our electronics combo for the scratch build kit, which you can find on our site here: https://buildyourcnc.com/item/electronicsAndMotors-3axis-425-elcombo. This is our standard general purpose 3 axis electronics system, and includes (3) NEMA 24 425 oz-in stepping motors, (3) Drivers (3.0Amp 24-40 Volts, with 1-1/64 microstepping), (1) 36v 8.8a Power Supply, (1) Interface Board either USB or Parallel. (The USB version requires PlanetCNC software; the parallel interface board gives you a variety of options, Mach3 being one popular choice.)

I am going to build a CNC 4x4 plasma table. The frame is made of 1 1/4" pipe and the gantry will be made of either 2"x 2" or 2"x 3" tubing. What size stepper motors do you suggest?

• how to calibrate stepper motors with ballscrews In mach3

The easy way is to use Mach3's calibration process to calibrate the axis with the ballscrew coupled to the stepper motor. This is done in the settings tab of Mach3 and clicking the button just above the "Reset" button called "Set Steps Per Unit". A dialog box will appear asking how far you want Mach3 to move that axis. Mach3 will move that axis at a distance that is determined by the existing steps per unit value set in the motor tuning dialog box (config menu -> motor tuning). Not knowing the distance that this axis will travel, it's best to use a very small value.

The more difficult way and the technique that should be used to create the initial value for the step per unit in the motor tuning dialog box. Use the steps/unit formula. This example will use inches.

Steps/Inch
= ((motor natural steps) x microsteps) / (the travel for one complete revolution)

The travel for one revolution would be the distance a ball nut will travel with one complete turn of the ball screw. This is generally the number of starts / threads per inch. Say the ball screw has 5 starts (5 threads starting from the beginning of the screw) and 10 threads per inch (TPI), then the travel for one complete turn of the screw would be 5/10, or 1/2".

Say you set the microstepping to be 1/4 on the stepper motor driver and your stepper motor has 200 natural steps per revolution (1.8 degrees per step), then the total steps would be 200 x 4 = 800.

So, the steps/inch is 800 / 1/2" = 1600 steps per inch

Hope that helps

how to calibrate stepper motors with ballscrews In mach3

• I AM CURRENTLY HAVING SOME PROBLEM SQUARING THE GANTRY AND MY STEPS PER INCH ARE NOT 1422.22 ACCORDING TO YOUR CALCULATIONS IN AUTO SET UP THEY COME OUT LIKE 1416.#### THIS A BIG DEAL?

Your steps per inch will vary. I suggest watching my calibration video.

I AM CURRENTLY HAVING SOME PROBLEM SQUARING THE GANTRY AND MY STEPS PER INCH ARE NOT 1422.22 ACCORDING TO YOUR CALCULATIONS IN AUTO SET UP THEY COME OUT LIKE 1416.#### THIS A BIG DEAL?

• HOW COMPLEX IS YOUR KIT TO ASSEMBLE, AND MOST IMPORTANTLY - HARD IT SETUP CONTROL THE LASER WITH MACH3?

The blackTooth Laser cutter and Engraver can be built in a weekend. Take a look at the build instructions and try to determine if you feel you have sufficient capability to put together the laser system.

HOW COMPLEX IS YOUR KIT TO ASSEMBLE, AND MOST IMPORTANTLY - HARD IT SETUP CONTROL THE LASER WITH MACH3?

• I am interested in your Black Toe (24" X 48") machine, and am wondering if using two medium motors on the "X" and "Y" axis makes sense relative to power and alignment (racking). What would you recommend?

it is possible to install 2 motors on a single axis but you will require another driver and motor, but wire it directly to the same pins on your breakout board. Also the orientation of your motor since it is opposite side of the original so getting it to move accordingly to the original motor it will need to be orientated correctly. The slight shift could be the cause of the rod not being completely flat where the set screws are suppose to tighten the sprocket to the rod, so sanding it to a flatter surface might fix the shift in directions.
Currently do not have a kit or schematic available.

I am interested in your Black Toe (24" X 48") machine, and am wondering if using two medium motors on the "X" and "Y" axis makes sense relative to power and alignment (racking). What would you recommend?

• HI, I HAVE INTENTION OF PURCHASING YOUR 1/2 INCH PRECISION LEAD SCREW SET TO BUILD MY CNC MACHINE, COULD THE SCHEMATIC DIMENSION ANTI-BACKLASH NUT, BEARING FOR AND SHIM? ALSO IS 2.2KW SPINDLE ABLE MILL ALUMINUM WHAT ACCURACY?

BYCNC response:

Milling aluminum is no problem with our machines.

Here is a video we recently did with our 4'x8' machine. The aluminum piece is about 1/4" thick: https://buildyourcnc.com/tutorials/tutorial-greenbull-aluminum-cutting

The accuracy you will see from our our 2.2kW spindle is entirely dependent on the precision of your build, so it's not possible to say what level of accuracy you can achieve without an examination of the complete system. However, our spindles have a runout of less than .0001 in, which includes the collets that we sell. If you use a collet from another manufacturer, we cannot guarantee this TIR (Total Indicated Runout) dimension.

User response:

User response:

BYCNC response:

• HI, I HAVE INTENTION OF PURCHASING YOUR 1/2 INCH PRECISION LEAD SCREW SET TO BUILD MY CNC MACHINE, COULD THE SCHEMATIC DIMENSION ANTI-BACKLASH NUT, BEARING FOR AND SHIM? ALSO IS 2.2KW SPINDLE ABLE MILL ALUMINUM WHAT ACCURACY?

BYCNC response:

Milling aluminum is no problem with our machines.

Here is a video we recently did with our 4'x8' machine. The aluminum piece is about 1/4" thick: https://buildyourcnc.com/tutorials/tutorial-greenbull-aluminum-cutting

The accuracy you will see from our our 2.2kW spindle is entirely dependent on the precision of your build, so it's not possible to say what level of accuracy you can achieve without an examination of the complete system. However, our spindles have a runout of less than .0001 in, which includes the collets that we sell. If you use a collet from another manufacturer, we cannot guarantee this TIR (Total Indicated Runout) dimension.

User response:

User response:

BYCNC response:

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