There are no markings or words. Just a stepper motor with 6 pins. I need a replacement but I don't know what to buy?
Any help or links to a new one?
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There are no markings or words. Just a stepper motor with 6 pins. I need a replacement but I don't know what to buy?
Any help or links to a new one?
Measure it, if it is 4cmx4cm, just buy a standard NEMA17 to replace it. I sell them on Ebay for about $20
Finding the pins are very easy... Just use a multimeter.
Use the circuit tester beep.. Connect two of the 6 wires to the multimeter and turn the motor by hand - if you don't get a beep or circuit closed, then switch to another wire..
You are looking for the 2 pairs you need, 1A,1B - 2A,2B. Keep trying pairs until you get the beep.
42.28mm X 42.28mm X 34mm is what my calipers are giving me.
34mm is the length.
So will yours work?
Yes but I only ship within Australia sorry, too expensive otherwise.
These guys ship world wide tho, they have good feedback
http://www.ebay.com.au/itm/NEMA-17-S...item19e282efb8
Well Geoff,
I got a replacement motor, but when I place my printer into Jog Mode and try to utilize the new motor it isn't working correctly.
Instead of the armature spinning in one direction, it just spins one direction then the other direction like a jiggle.
Any suggestions, I really need my printer and am getting really frustrated.
Are there six wires in your original connector wire?
Are there six connections on your new motor?
Yes and Yes.
I presume the wiring is the same. Also spinning the armature on the new motor is fantastic nice and smooth. While the old motor is very difficult to turn by hand and the bearings on the inside spin freely so it may have something to do with the magnets?
After playing with the old motor it is spinning more freely now.
you need to measure the resistance between the connections on the new motor.
http://www.talkingelectronics.com/pr...pperMotor.html
Just down that page a short way is an explanation of the difference between 4, 6 and 8 wire steppers. You can see that centre to outside will be half the resistance of outside to outside. Using that you can draw the wiring of the pins for your new motor. Repeat for the old motor and see if they are the same.
I appologize for the late reply, my friend had my multimeter and recently purchased me another one to use.
When you say Circuit tester, the functions I am using is the continuity test.
Is this correct? Also I do not know what you mean by the 2 pairs, 1A, 1B -2A,2B. Can you explain further?
Your motor has 2 coils inside, these are called (for example) coils 1 and coil 2. Each coil has 2 ends, these are called A and B so you have 4 connections, call them 1A 1B 2A 2B. That is the standard notation that everyone uses for a 4 wire motor.
It is explained in the link I posted.
You normally want resistance test not continuity but it does depend on your meter and exactly what you are trying to do.
Well I have found the two pairs of pins that show resistance, on my new motor. I will pull off my old motor and check that also.
My main question is the wiring. Do the two pairs or A and B have to be wired to a matching A and B from the old motor? Like A to A and B to B or can I swap them around?
So I installed the new motor and it is extremely loud and it runs really warm. So warm that it melted some of the nylon standoffs.
I lubed all the guide rods and tightened all my screws and am still getting a really loud motor/printer. Now I am looking to purchase another motor and found the following website:
http://www.omc-stepperonline.com/ste...rs-c-1_21.html
Am I looking to purchase a unipolar or bipolar motor?
- If your motors getting toasty you may not have the right voltage stepper. I would test the motor driver with your multimeter and see what the driving voltage is and make sure the motor is rated to handle it.
Examples of different Nema 17 Steppers:
3.4V Stepper
12V Stepper
24V Stepper
*PS: These are just examples of the different Nema 17 style motors, I have no experiences with these sellers.
- Measuring the voltage will vary depending on what type of board you have and how the driver input power is sent. The place you need to measure the voltage is at the "Driver Power" source; see image below for an example.
http://bildr.org/blog/wp-content/upl...-arduino-2.png
I finally had time to open up my machine and found the following:
http://i.imgur.com/2QHusYk.jpg
I presume to measure the voltage I use the GND and VMOT, is this what you would do?
Edit: When I measure the voltage through the above mentioned terminals, I am reading 24 volts. This doesn't sound right.
- Yes, that is correct.
- Yes, this is also correct. Seems like your running a 24v setup, which is very nice because they tend to draw less amps. That will however make a lower voltage motor get real toasty for sure. You'll need a motor in like THIS (I don't know this seller; just using as reference).
Edit: Make sure to use the GND that's next to the VMOT when measuring, not the one at the top.
Working voltage on stepper motors in the days of modern electronics is meaningless. The driver circuitry is a current limiting device so no matter what voltage the stepper is rated at it is the current that is controlled.
If your driver circuitry cannot achieve the maximum rated current of the motor then the motor will not produce maximum torque.
Which is what I said worded in a different way.
If you have 2 stepper motors, one being 12 volt and one being 24 volt but both rated at 2 amps then the power output, at maximum volt and current, of the 24 volt one will be twice the power output of the 12 volt one (assuming the same efficiency).
If you run them from 12 volt then the power output from both motors will be the same because it is the current that is regulated, not the voltage.
In reality the 24 volt one will produce slightly less power than the 12 volt one when running from 12 volt because the magnetising power needed on the 24 volt one will be higher than the 12 volt one but you will not notice a difference in real usage.
In the environment of 3d printers you are unlikely to come anywhere near needing the maximum of any stepper motor no matter what voltage or current it is rated for.
The stepper driver limits the current, it doesn't care what voltage you apply as long as you do not exceed the maximum of the driver circuitry which is around 35 volts for the chip that is most commonly used.
If you set the current to some value less than the V/R value of the system then all that will happen is that the stepper driver will drop the voltage applied to the stepper motor because the stepper motor must obey Ohms law whereas the stepper driver does not obey Ohms law. This is assuming that we are not in the realms of the dynamic impedance of the motor affecting the current flow which we will almost certainly never be with the speeds used in these types of machine.
You can use a 24 volt supply with a 5 volt stepper without any damage at all. This is achieved by regulating the current with the stepper driver adjustment to a value that the 5 volt motor can handle, the stepper driver will regulate the voltage to 5 volts automatically, that is the whole reason to use current controlled drivers.
Good info, I will have to do some playing around with my multimeter. I guess I still got some learning to do.
Assuming the correct motor type, eg: 6 wire, 4 wire, 8 wire then the questions in the correct order are:
Is the motor the right size physically?
Does the motor have suitable torque?
Is the specified current of the motor within the adjustment range of the stepper driver?
Is the specified voltage of the motor lower than or equal to my power supply?
So where should I begin?
My motor is the right size, but I have no info on the previous motor.
Would measuring the current while the machine is on, help? If so would you place the multimeter in the same place to check voltage?
After some research I purchased the motor (12V 0.4A) from the link below:
http://www.ebay.com/itm/331084351443...%3AMEBIDX%3AIT
So after reading the responses above and trying to remember my electricity and magnetism physics. It sounds like them motor I purchased has low torque and draws low amps, compared to what was originally in the machine?
After more research I have found that the board to control everything is based on the Makerbot MightyBoard:
http://www.thingiverse.com/thing:16058/#files
looks like Steppar 42!?
I do believe its a Nema 17 motor.
Any input on what I should purchase? I feel like the current motor I have has a low amperage, compared to what the stepper drive is delivering. So it is then overheating.
Adjust the current
On the mighty board you can do this in software.
In your Gcode you should have a line like this:
G130 X0 Y0 A0 B0; set stepper motor vref to lower value while heating
Later in your Gcode you should have this:
G130 X127 Y127 A127 B127; set stepper motor vref to defaults
The first line turns off the steppers and the second line turns them on again.
If you change the second occurrence of the line to:
G130 X64 Y127 A127 B127
it will drop the current for the X stepper to about half what it was.
The lower you make it the lower the current will be but also you will lose power so probably you cannot print as fast as you could. Try lots fof increasing values until you get a reasonable speed without skipping steps. Once you get there make sure the stepper is not getting too hot.
Those lines should be in your start.gcode so you can save the value you decide on to make it permanent.
This is the beginning of the Gcode that I have. I see the first option you mentioned but not the second. Where should I add it?
Never mind I see it now! Right now its set at Y127. Its the Y motor that is over heating. So should I lower it to Y100?