### Question #: 14163

Question:
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hello there, i am using servo motor for my X and Y Axis but i dont know how to calculate steps/mm for that, the lead screw i am using is have pitch of .5 mm. please helpme on this i have done everything only this point is pending.
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**The formula for finding the steps per mm is found in the units itself. First, you mentioned that the motor is a servo. This needs to be clarified as a servo is different than a stepper motor. Some servos behave similar to a stepper motor, so I will continue with this in mind.
The formula is (steps/mm):
You need to find the steps. The stepper motor has a natural number of steps per a full revolution. This is typically 200 steps per revolution.
The driver for the stepper motor allows you to increase the number of steps per revolution by adding a specified number of steps between each step. For instance, if you set the driver to 1/4 microstepping, then instead of having 200 steps per revolution, you would have 200 x 4 = 800 steps per revolution.
So now we have the first part of the formula:
Steps / mm = (200 x 4) / mm
Lets determine the mm side of the formula:
You mention that the pitch is 0.5 mm. Check to insure that the lead is also 0.5 mm. This could be a multiple start lead screw where the pitch is different than the turns per mm. If in this case, that the 0.5 mm is the travel for one full revolution, then you can simply plug this into the formula as:
mm = .5 mm
Otherwise, determine how fat the travel is for one complete revolution.
Therefor, with what we know and the driver is set at 1/4 microstepping and the stepper motor has a natural step count per revolution at 200:
steps / mm = (200 steps x 4) / 0.5 mm = 800 steps / 0.5 mm = 1600 steps / mm
If your travel for one revolution is not 0.5 mm, then plug in your travel distance instead.
Additional Information:i know about steps/mm calculation for stepper motor, because i am using servo motor that why i asked about that. please tell for servo motor.Additional Information:because its my first time with servo motor i have no idea about calculation of parameter with servo.Additional Information:Have you attempted to contact the manufacturer or seller of the servo? We typically respond to customers of our products on this customer service area, unless we have extensive knowledge of the subject and can answer the question efficiently.**

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### Other Possible Solutions to this Question

**On the Book Build: I'm changing the 13TPI 1/2" lead screw with the 1/2" 10 TPI Acme screw with the anti backlash nut. This is for the Z axis only. What should I know about installing it and what are the numbers I need to plug into the motor tuning area.**The settings that will have to be change will be your steps per inch in motor tuning (mach 3), or settings/axes(planetCNC). But we do not have the actual numbers/specs that will fit your 10 TPI 5 start lead screw, here is a tutorial video which explains how to get the exact numbers you need! (

).

Here is a default setting that you might be able to tune and adjust accordingly: 1600 steps, accel 400.02, velocity 5.**I have an engine NEMA 34 from Y axis on my green bull that do not response, I already check connections and everything seems to be OK, how can I check that the motor it's working properly or not?**If one or more motor is not responding, please follow the troubleshooting directions below:

For parallel Bob only! Make sure both the parallel and USB are connected.

Re-check wiring, and connections for continuity (no breaks in the wires) and check for correct wiring locations from driver to BoB.

Check dip switch settings on the driver.

Check components, by swapping the motors (ex. y-axis motor to z or x-axis driver and z or x-axis motor to y-axis driver) to check if motor functions on another driver.

Depending on software check step low active (mach 3) or invert pulse (planet-cnc) for the axis which is not responding.

Mach 3 - config/port & pins/motor outputs / Planet-CNC - file/settings/axes**Click the link to respond:**

I have an engine NEMA 34 from Y axis on my green bull that do not response, I already check connections and everything seems to be OK, how can I check that the motor it's working properly or not?**How do I order 3 specific lengths of lead screws in one order? I could only order a single total amount via the shopping process. I require 36", 60" and 14". If I order 110", I will get 79" + 31". Do I have to order 115" and pay for an extra 5" to get around this?**Just specify the full length in the quantity field in the shopping cart and give us a call to inform us of the cut lengths (you can also email customer service - link in the contact us page - link at the footer). We are working on a way to do this at the product page, but won't be finished for a few more days.

Additional Information:

20**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)

R = radius of the lead screw

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

Additional Information:

Additional Information:

Additional Information:

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

Additional Information:

Pls

Additional Information:

1m 16mmdiameter ball screws calculations**I wpold like to know how to hook up my water pump (12vdc 9 amp) to turn it on and off using Mach 3. I have your Blue Brew break-out board Rev. 2.8 dated 8-12. Explain how the three relay connections work for this application? Thanks.**Since the pump will use a standard 12v power supply, you will have two wires. One of those wires will be connected from the power supply to the pump. The other wire will be connected to the power supply and the pump, but cut that wire and connect one side of it in the P terminal and the other end in the S or the O terminal depending on if you need the connection as NO (Normally Open) or NC (Normally Closed).

Step number 9 in the instruction will have the relay connection information:

https://www.buildyourcnc.com/item/electronicsAndMotors-parallel-breakout-relay**Click the link to respond:**

I wpold like to know how to hook up my water pump (12vdc 9 amp) to turn it on and off using Mach 3. I have your Blue Brew break-out board Rev. 2.8 dated 8-12. Explain how the three relay connections work for this application? Thanks.**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 for determing the maximum weight motor can handle on Z-axis on book build cnc. 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**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)

R = radius of the lead screw

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

Additional Information:

Additional Information:

Additional Information:

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

Additional Information:

Pls

Additional Information:

1m 16mmdiameter ball screws calculations**I am building your "Green Bull' 6 foot wide kit and I am at the stage of attaching the motor and drive chain. I would like to know if you have an modification kit available to put the 1/2" ACME screw on the Y-axis?**Currently we do not have that modification kit, our set up is fixed for our greenBull only modification kit we have for this model is the long z-axis kit(Designed for Foam cutting).

**Click the link to respond:**

I am building your "Green Bull' 6 foot wide kit and I am at the stage of attaching the motor and drive chain. I would like to know if you have an modification kit available to put the 1/2" ACME screw on the Y-axis?**How to determine lead screw length needed. My Thomson 1 1:4 rails are 60 inches long roughly for the router I’m building. I know I have to have it long enough to couple up with the stepper motor of course but does it matter if it’s a little long on the other end**It generally does not matter if it is longer at the other end as long as the lead screw provides the desired travel for that axis. The lead screw will only need to be long enough for the travel, plus any structure and lead-nut positioning.

For example:

- The motor that will turn the lead screw will need to be mounted at some position (generally at one end of the axis). In many cases, this positioning will be mounted where some of the lead screw will not be used (the lead nut will not be able to moved close to the coupling of the lead screw to the motor shaft). Add some of the length of the lead screw to be inserted into the coupling.

- If the lead screw will contain bearings at either end of the travel, that portion of the mechanical assembly will need to be considered in the lead screw length.

- The lead-nut will need to be mounted in a position on a structural member of the part that is to move. The distance from the part of the structure that will extend closest to the motor will have some distance to the position of the lead nut. This distance will need to be added to the lead screw length.

Add these discrepancies to the length of the lead screw and the travel length and you will have the final length.**My Nema 24 motors make high pitched alarm sound when changing directions quickly - what could be the cause? Red LED is lit on Microstep Driver CW230 but everything seems to run fine - is this a problem?**Stepper motors are known to make different type of noises when in motion. So there should be no issues in regards to accuracy with the steppers. You also might be able to lower the noise that comes from the motors, by adjusting the acceleration and velocity of the motors. This usually tends to either make different noises or lowers the pitch of the noises.

Cool video(personal opinion, does not relate to BYCNC):**Click the link to respond:**

My Nema 24 motors make high pitched alarm sound when changing directions quickly - what could be the cause? Red LED is lit on Microstep Driver CW230 but everything seems to run fine - is this a problem?**I am making my own CNC setup using all the electronics from your website and I have many questions. Please advise how to have my computer recognize the USB connection from my breakout board also I would like to use a water cooled spindle but I need to know the parts required for a 4x10 bed area used for woods and plastics**You will need PlanetCNC software for the USB breakout board and when plugging in the USB the computer should automatically recognize the board, however you can go into device manager to see if the USB terminal is working correctly.

The parallel breakout board; the USB is not a connection terminal rather than a power source, and the parallel port will be the communication terminal.

The items you will need for a water cooled spindle would be: water pump, silicon tubing(length desired by customer), a extension cord(from a hardware store(orange))(1 same gauge wire/length as extension cord).**I just ordered a 1/2" lead screw and bearings, etc. But I don't see any 1/2" shim washers for those bearings. If you have any, please toss 8 of them in the shipment and I'll gladly reimburse you.**We will provide shim washers as a part of machine assemblies, but when purchasing lead screw and bearings, the shim washers must be purchased as well. Please give us a call and we can send them out.

**Click the link to respond:**

I just ordered a 1/2" lead screw and bearings, etc. But I don't see any 1/2" shim washers for those bearings. If you have any, please toss 8 of them in the shipment and I'll gladly reimburse you.**I am building a cnc router with twin ball screws on the long axis and I will have a rotary axis as well. I need a 5 axis breaker board using only 4 axis total. Can you help me?**Yes, we can make a redLeaf system that has all 6A drivers for use with the 651 oz-in motors. We can also wire the electronics in a way that two of the drivers will use the pins of the same axis so that axis will drive two drivers and motors.

**Click the link to respond:**

I am building a cnc router with twin ball screws on the long axis and I will have a rotary axis as well. I need a 5 axis breaker board using only 4 axis total. Can you help me?**Hi I built a 2x4 cnc machine in 2013 using you Hardware kit and plans. I want to speed up my cnc machine by purchasing your acme leadscrew 1/2"-10 5 starts. I have an X axis at 52", a Y axis at 32" and a Z axis at 14". How do I order all 3 length pre cut to size on your website? Also can you give me a rough estimate on the shipping to Ottawa, Ontario Canada please.**You can purchase the entire length and select local pickup. Then you can email us the cut lengths for the order and let us know that you need to be invoiced for shipping. We will provide shipping estimates according to the real lengths and dimensions of the package. You can select the estimate that meets your shipping budget and we will invoice you the shipping amount and send the order.

**I have NEMA 34 motors for a GreenBull 6x12. After 2 weeks of use, my Y axis motor has developed play in the front but not rear of the motor. Is this a motor defect or has something come loose somewhere? Thanks,**If there is play within the motor itself, then that motor may be defective. Call us to provide us more detail on this issue.

**Click the link to respond:**

I have NEMA 34 motors for a GreenBull 6x12. After 2 weeks of use, my Y axis motor has developed play in the front but not rear of the motor. Is this a motor defect or has something come loose somewhere? Thanks,**On Mach3 USB the port number is 3 but i dont see the motor output pin numbers for the stepper side? could you please provide this for me? maybe a sketch of all the pin numbers the way Mach 3 sees them?**The step and direction terminals on the Mach3 USB controller are the terminals labeled XP, XD, YP, YD, ZP, ZD, AP and AD. The P is the pulse or step terminal and the D is the direction terminal.

The configuration for the motor outputs are already configured in the Mach3 configuration file that is available on that product page:

https://www.buildyourcnc.com/item/electronicsAndMotors-electronic-component-breakout-Mach3-USB-Board**Click the link to respond:**

On Mach3 USB the port number is 3 but i dont see the motor output pin numbers for the stepper side? could you please provide this for me? maybe a sketch of all the pin numbers the way Mach 3 sees them?**Can you preset an origin point on this cnc? How long does it take to jog over? (If I have the case that I using the same thickness of maple wood, and same jig everytime)?**Yes, you can preset an origin by zeroing the machine at the desired location before beginning your work. You can return to that exact point at any time, or you can specify an offset from that point to be the beginning point for the next machine operation (for instance when cutting several parts from one sheet of wood.) Jogging time varies by machine and application but would generally be a rapid move -- our default rapid setting is 400 inches per minute.

**Click the link to respond:**

Can you preset an origin point on this cnc? How long does it take to jog over? (If I have the case that I using the same thickness of maple wood, and same jig everytime)?**hello, my question is, I recieved two breakoutboards exactly the same, do I need them both for my greenbull 4x8 also, I cant find any tutorial showing the installatio and placement of the limit switches, can I have some assistance please? sorry fot he bad english and thanks.**No, you should not have received two parallel breakout boards in your CNC kit. You can return the extra item using standard shipping with COD. Our apologies for the confusion and the inconvenience.

I will answer the other question as another FAQ. Please check the Customer Service page to see the answer to that question.

If you have difficulty finding the answer, here is a link:

https://www.buildyourcnc.com/FAQ/13636**AM NOT SURE HOW TO SET THE Z AXIS TURN ON/OFF LASER WHEN CREATE CODE. KNOW THAT ITS TYPICALLY Z-AXIS MOVEMENT DOES THIS - BUT YOU DONT SHOW ANYTHING HOOKED UP IN PLACE OF AXIS.**When the z axis is going down, the laser turns on. When the z axis is going up, it turns off. The z axis directions is only a signal that is either 5v or 0v. That determines the direction. In vectric, you will need to set your machining operations with a very very small depth so the time it takes to get to its final depth is a very short time.

**Click the link to respond:**

AM NOT SURE HOW TO SET THE Z AXIS TURN ON/OFF LASER WHEN CREATE CODE. KNOW THAT ITS TYPICALLY Z-AXIS MOVEMENT DOES THIS - BUT YOU DONT SHOW ANYTHING HOOKED UP IN PLACE OF AXIS.**When I first hooked up my redFly and was manually testing all the axes, everything was going well, then my Y axis stopped working all together, and now my X and Z have stopped also and my redFly has a nasty smell coming from it and none of the stepper motors seem to be getting power.**Since you mentioned there is a nasty smell, I'm wondering if there might have been a issue with the power supply. Can you email us your name for the order and specific voltage you are using for the redFly? at techsupport@buildyourcnc.com. Also I want to mention if you have the USB cord plugged in to the redFly if it has the parallel interface board?