Talk:Stepper motor

Removed items
I removed the following text from the main page. Please feel free to readd it in a more coherent form.

> Stepper motor movements and speed are defined by which poles are on or off.

> Stepper motors are similar to DC Brush less motors due to the fact that they use poles in conjunction with magnetism. Insert non-formatted text here > Hard drive motors can be "sort of" thought of as stepper motors because the servo must use some kind of pole system to know where the spindle is to send it to the chip. But they are not STEPPER Motors; they are a type of DC Brush less.

> Stepper motors have been used in micro machines.

> Stepper motors are kool.

kmccoy (talk) 01:53, 11 Apr 2005 (UTC)

Things to add
I might get to these later...


 * Better description of why the voltage doesn't matter as much. (It matters only when you're trying to drive at high speed)
 * Resonance problems - from load, and also driving at some frequencies >>> This leads to more constant-motion applications than dynamic.
 * Load interia vs. rotor inertia - steppers only operate in a narrow range
 * 5 phase motors (I don't know much about these)

Anyone want to add schematics to show some of the things described? (the coils, the transistor drive)

Can u also add some data as to what will happen if two of the consecutive stators are simultaneously charged? 202.41.93.129 04:36, 21 March 2006 (UTC) AD


 * It increases torque some (maybe by 50% based on what I've read), and obviously doubles the power used. Dreadengineer (talk) 05:34, 27 January 2008 (UTC)

I plan to play around with Inkscape, post the SVG code so you can improve it. Scheduled for this weekend, please give a note here, If you are already working on this.--Arnero 18:07, 5 May 2006 (UTC)
 * Usually I draw "comparisons". So I could compare coil arangments.
 * I can also try to draw an electric schematic.
 * I can draw a timing diagram, but that gets lengthy and is something the reader better clarifies on her/his own

I added a physical description of how step motors work and some text to go with the figures; I thought it was kind of hard to get a basic idea of what step motors are from the page before. I also organized the unipolar vs. bipolar information.--Dreadengineer 09:17, 20 December 2006 (UTC)

Sizing would be useful, a list of the NEMA standards, and if there are any standards for the can type. ˥ Ǝ Ʉ H Ɔ I Ɯ (talk) 03:22, 2 December 2014 (UTC)

Fundamentals of Operation
I changed the "Fundamentals of Operation" back to an earlier version, with a few edits. Stepper motors are very commonly used by hobbyists, so it's important to have an easily understood explanation of their operation. The previous explanation used terms such as external commutation, phases of a motor, magnetic reluctance, etc., all of which are valid, but are unnecessary for a basic understanding of fundamentals of operation. They should go in a different section, and the "Fundamentals" section should give a quick, basic understanding of how steppers work.Dreadengineer 05:22, 21 September 2007 (UTC)

Images
The images that illustrated stepping had been removed with the note that they were "wrong." I'm assuming this meant that the images are not the same as the actual construction of stepper motors. But the images are effective at communicating the basic idea of how stepper motors work. Also, they are not very different from motor construction; see the "hybrid" image on this page: http://www.ams2000.com/stepping101.html or this one: http://www.sapiensman.com/step_motor/. It's true that the images don't illustrate that parts of the stator on both sides of the rotor will be energized, but adding that would add confusion to the picture and is unnecessary to explain the principle of operation. We can discuss it here if anyone disagrees. Dreadengineer (talk) 05:34, 27 January 2008 (UTC)

The animated image in wrong in that stepper motors don't work that way. In a 2-phase stepper motor, there are just two electromagnets and the stepping sequence involves changing polarity. It is a nice image, but it is wrong. Having a wrong image is worse then having no image. The image is wrong, the description below the image is also wrong. The image should show the two coils opposite each other working together and changing polarity. Like at http://en.nanotec.com/steppermotor_animation.html FreedomSeven (talk) 21:45, 13 May 2011 (UTC)

FreedomSeven, you're thinking of a bipolar stepper motor. The animation is of a unipolar stepper motor, which does work the way shown. Also, the motor in your link is a brushless DC motor, not a stepper motor. That page seems to be illustrating the driver circuit, not the motor type. Notice that their motor picture is the same when you select the brushless DC option. Dreadengineer (talk) 05:52, 15 February 2012 (UTC)
 * Freedomseven is correct, Dreadengineer is wrong. The figure is wrong and does not describe any successful unipolar motors.  All motors with 4 opposed motor poles in the stator (toothed or not) have the poles wired in pairs, in series, so that the magnetic forces on the rotor are balanced and don't load the motor bearings.  In unipolar motor (that is, one with 3 wires per motor winding, one being a center tap), both motor windings are wound on both of the opposed stator poles.  These are bifilar windings.  Specifically, bifilar wound, series connected, with center tap connected where the two windings are joined in series. Douglas W. Jones (talk) 22:12, 2 July 2013 (UTC)

Also, I'm not sure of the value of the last image on the page, which talks about motor configuration and says "everything is combineable." It's not clear what is illustrated by the image; it seems pulled from a page that talked about it in more detail. Does anyone think it adds value? Dreadengineer (talk) 05:48, 27 January 2008 (UTC)

Switch reluctance drives
hello,

Do SRD's bear any similarity to stepper motors as i tried looking for them on wikipeida and all i got was stepper motor.

Hre is a site that has a little info on SRD's

Switch reluctance drives

many thanks

wouse101 (82.3.201.199)


 * A "switched reluctance motor" is one type of stepper motor. A "switched reluctance drive" is the drive electronics or an adapted to that form of stepper motor or the entire drive system, electronics and motor.


 * Atlant 15:55, 13 September 2006 (UTC)

Comparison recommended
I recommend that the following sections be added: Juxtaposition with other brushless DC motors Juxtaposition with other electric motors

1930 Step-by-step motors
I found a Naval Electrical Pocket Book from 1933 at a car-boot sale, and was surprised to learn that step-by-step motors were used as early as the 1930s for setting the firing elevation and deflection on battle ships:



The device was electro-mechanical and human operated. They even did half-stepping. Should there be a History section in here? —The preceding unsigned comment was added by 213.58.97.242 (talk) 16:41, 15 January 2007 (UTC).

It could have a history section; other motor articles don't, though. Motor technology in general has been around for a long time. Dreadengineer 05:22, 21 September 2007 (UTC)

Why is Microstepping/Halfstepping not covered?
I'm not very familiar with the subject or I would attempt to add a section or is there a reason there is nothing in the article regarding half stepping? Thorney 05:58, 12 May 2007 (UTC)

One important and popular application of stepper motors is in electronic (quartz) watches and clocks with an analogue face. The motor is used to drive the 'second hand' in steps of 1 second.-

Spam
A link to electojects.com has been repeatedly added to Stepper motor, Electric motor and Brushless DC electric motor by Special:Contributions/217.53.109.235, Special:Contributions/82.201.156.201, Special:Contributions/217.53.107.168, Special:Contributions/217.53.16.164, and others.

The link in question is registered to Abdoh Ali Mohamed, Hay Swesri, Nasr City, Cairo, Egypt.

I wonder if the four IP addresses listed above have any connection... Naw, couldn't be. Egypt is a big country. Must be a coincidence.

I'm going to start patrolling wikipedia for any links to electojects.com or redirects to it and deleting them on sight. If they come back, I'll move to blacklist the address. Mdsummermsw (talk) 18:07, 28 December 2007 (UTC)


 * I saw the website electojects.com/motors and I wonder why you consider it a spam. It has many tutorials on electric motors including stepper. It is informative website (regrading of ads) from my point of view. —Preceding unsigned comment added by 196.205.193.74 (talk • contribs) 18:15, December 28, 2007


 * Let's get real. You didn't just "see" that website. That link has been removed dozens of times from about a dozen articles by numerous editors who have identified it as spam. Here's why: Spam. By the way, awardspace.com is next. - Mdsummermsw (talk) 18:49, 28 December 2007 (UTC)


 * Why it is a spam, IF it is a relevant and useful for readers, then it shouldn't be removed. - —Preceding unsigned comment added by 196.205.193.111 (talk • contribs) 19:00, December 28, 2007


 * I'm sorry, annonymous editor from Egypt, that is incorrect. Please read Spam (heck, read all of WP:SPAM). Also consider registering for an account. It seems that all of your contribs so far have been bare links to electojects.com and awardspace.com (I'm looking for others as well). Registering an account would keep all of your contributions under one name so that we might be able to see any contributions to actual content that you make. If your intentions are merely to drive traffic to your sites, though, this would unmask that as well. If you truly only intend to be helpful, as you claim, registering is your logical move. - Mdsummermsw (talk) 19:11, 28 December 2007 (UTC)

The awardspace.com link is from the same source. . - Mdsummermsw (talk) 19:01, 28 December 2007 (UTC)


 * Why it is a spam, IF it is a relevant and useful for readers, then it shouldn't be removed. —Preceding unsigned comment added by 196.205.193.111 (talk • contribs) 19:09, December 28, 2007
 * Don't work like bots. —Preceding unsigned comment added by 196.205.193.111 (talk • contribs) 19:14, December 28, 2007


 * Please sign your additions to talk pages. End all of your comments with ~ and it will add your username or IP address and the time. Thanks. - Mdsummermsw (talk) 19:17, 28 December 2007 (UTC)


 * Ok, then we should put a link in one article only (the most relevant). —Preceding unsigned comment added by 196.205.193.111 (talk) 19:25, 28 December 2007 (UTC)


 * That's not how it works. The link must belong in the article according to policy. It does not. So out it goes.
 * So far today, I've removed that link from Repulsion motor‎, Motor controller, Electronic speed control‎, Reluctance motor‎, Unipolar motor‎, Induction motor‎, DC motor‎, Synchronous motor‎, Electrostatic motor‎, Linear motor‎, AC motor‎, Electric motor‎, Brushless DC electric motor and Stepper motor. I'll run a full search shortly.
 * I strongly suspect the only contributions you have made to wikipedia are those links to your websites (and, perhaps, others). If this is not the case, please tell me what other contributions you have made.
 * Until then, I will continue removing these isolated spam links. Then I'll be removing your awardspace.com one as well. - Mdsummermsw (talk) 19:33, 28 December 2007 (UTC)
 * Add Synchronous condenser and Motor to the list. The last one is a dead ringer. The page is a disamb, and the link does not help with that! - Mdsummermsw (talk) 19:39, 28 December 2007 (UTC)


 * Do what you think it is right and good for wiki. —Preceding unsigned comment added by 196.205.193.111 (talk) 19:45, 28 December 2007 (UTC)


 * Thanks. Same to you. - Mdsummermsw (talk) 19:50, 28 December 2007 (UTC)

I have now removed the same user's links to her/his other site at awardspace.com from Stepper motor, Electric motor, Motor controler, DC motor, Brushed DC Electric Motor, Electrostatic motor, Motor and -- the kicker -- Stepper which has no relationship to the rest, other than the name. - Mdsummermsw (talk) 20:03, 28 December 2007 (UTC)

This website (electojects.com/motors) is helpful, you havn't to remove it.217.53.108.172 (talk) 22:56, 28 December 2007 (UTC)
 * You've already said that, annonymous editor from Egypt. Do you have a new argument? - Mdsummermsw (talk) 14:02, 30 December 2007 (UTC)

An additional comment on this issue has been added to Talk:Electric_motor. - Mdsummermsw (talk) 13:31, 31 December 2007 (UTC)


 * I don't see why it is spam. It has 1)relevant information, 2)nothing for sale 3)no ads.  It does not have to be a news article to be a good reference.  —Preceding unsigned comment added by Stuston (talk • contribs) 18:01, 5 February 2009 (UTC)

Clock Motor
I have just taken a quartz clock to pieces and the motor in it has a permanent magnet rotor and a long U shaped stator with a coil around it: the ends of the U nearly touch the rotor. Why does it go around only one way in half turn steps each second? there is no mechanical ratchet. Also, this type of stepper motor is not described in the article. --83.105.33.91 (talk) 10:48, 22 April 2008 (UTC)

This is a stepper motor. This has a very simple design and with each pulse the rotor moves 180 degrees and this is geared down to the seconds hand. The design is not critical on the pulse width or the pulse height (within limits) and depends on the frequency alone. Basically it has only one coil and two poles with a (ferrite) magnetic rotor. I do not know how the direction of rotation is established.Ck.mitra (talk) 08:05, 8 October 2009 (UTC)

Could someone clarify?
As a student, having read the article I still don't understand why it is required to reverse the polarity of the electromagnets at all - the clear demonstration using images suggests you just need to switch electromagnets on and off. Am I missing something or does the article not make the link between switching electromagnets on and off and having to change their polarity? —Preceding unsigned comment added by 195.137.75.44 (talk) 15:33, 29 November 2008 (UTC)


 * The pictures show a simplified version of a unipolar stepper motor, and unipolar steppers do not require changing polarity. Bipolar stepper motors are probably the more commonly used type, and they do need reverse polarity. The description in the article is a little vague; you may want to google for more description of the two types. Dreadengineer (talk) 04:56, 15 January 2009 (UTC)


 * The pictures appear to show the operation of a Switched Reluctance Motor, (one without a magnetized rotor), rather than a unipolar motor. It would appear entirely possible to drive a SRM in the way the questioner speculates.  However in a more typical permanent magnet stepper, the rotor contains a magnet and alternate teeth are magnetized with opposing polarity.  By energising the winding to cause flux in one direction, rotor teeth of a certain polarity are attracted toward the energised stator teeth.  By reversing the flux (in either a unipolar or bipolar motor) the same rotor teeth are repelled away from the energised stator teeth.  Therefore reversing the magnetic flux, rather than simply switching current off, is an important part of achieving optimum stepper performance. Mark Beard (talk) 17:39, 3 July 2009 (UTC)


 * In an unipolar motor, the coils are either energized or not. Hence there is no change in the polarity in the coils.  When the next coil the energized, the magnetized tooth is attracted towards the nearest coil.  In a bipolar motor, the current direction is reversed and therefore both attraction by the next coil and the repulsion by the previous coil generates a greater torque.
 * Unipolar motor drivers are easier to drive as the electronics needed is simpler. Bipolar motors need more complex circuits as the currents in each coil is either one way or the other.
 * For the same current, bipolar motors generate greater force or torque. However, average current in unipolar motors is about half that of bipolar motors.  Hence bipolar motors run hotter.  Most unipolar motors (with center tapped windings) can be used as bipolar motors (ignoring the center tap).Ck.mitra (talk) 19:18, 19 February 2010 (UTC)
 * The notes above are correct, but may not be understandable since the explanations are not in lay terms. Essentially a unipolar application is analogous to a gas engine, where the motive force comes from an intermittent a pressure on one side of a cylinder.  The alternative is a steam engine, where the pressure is alternately applied to either side of a cylinder.  By moving from unipolar to bipolar, the each coil can not only pull on a rotor pole that it needs to approach, it can also push against a rotor pole that it needs to move away from.--LifelongEngineer (talk) 18:43, 18 October 2009 (UTC)

mistake in references?
Is there mistake in point number one of references? It is reference to book "Instrument Engineers'...". On wikipedia page it says that the information about types of stepper motors are on page 2464 of that book, however they are on page 1377. Is it right? —Preceding unsigned comment added by Rumcajs00 (talk • contribs) 14:39, 13 June 2009 (UTC)

added to types
I added some definition to motor types and made a minor change in the introduction, eliminating the reference to "normal DC motor". There is nothing abnormal about a stepper motor, it's a conventional synchronous DC motor. The original reference to "normal DC motor" is probably referring to an asynchronous DC brush motor. The concept of "normal motor" is colloquial and is open to interpretation based on the experience of the reader. Overall, this article needs quite a bit of correction to get to proper descriptions in terms of physics and the engineering of electric machines. --LifelongEngineer (talk) 01:37, 23 September 2009 (UTC)

You are absolutely correct. If you draw the pulses with sine/ cosine waves, you can see that stepper motors are basically synchronous motors with rotors replaced with permanent magnets. As stepper motors are small (usually) this causes no serious problems. Large synchronous motors will need slip-rings and coils on the rotors. This aspect becomes very clear once you drive the stepper in the microstepping mode when the analogy to the sine/ cosine drive waveform will be apparent. Also you can see in microstepping mode there is absolutely no way to stop the rotor in an arbitrary position.

Another important difference is that in "normal" motors, the poles on the rotors are usually slanted at an angle to prevent latching. But this is precisely the effect we need in stepper motors and the poles are parallel to the axis.Ck.mitra (talk) 08:17, 8 October 2009 (UTC)
 * "in microstepping mode there is absolutely to stop the rotor in an arbitrary position"? that makes no sense whatsoever. the current position is determined by the phase angle, which can certainly be held at a specific value. -- 99.233.186.4 (talk) 18:48, 10 July 2010 (UTC)

We may have a background of different engineering terms. The slant or skew found in the rotor laminstions of brush type DC motors and AC servo motors is to reduce cogging, the sine wave of torque that is superimposed on the intended torque generation. I suspect this is what you mean by latching--LifelongEngineer (talk) 18:48, 18 October 2009 (UTC)

clarification about types
The article lacks some clarity and completeness about the distinction between parmanent magnet stepper motor and variable reluctance stepper motor. Some sections only apply to one type without even mentionning it.

For instance : in the introduction "Stepper motors are similar to switched reluctance motors": this applies to variable reluctance motors. The animated image describes a VR motor too. "fundamentals of operation" too.

The section "two phase stepper motors" only describes permanent magnet stepper motors.--Olivier.rieux (talk) 14:12, 15 June 2010 (UTC)

caption mistake
I believe the operation described in the figure in phase current waveform is that of a two phase unipolar stepper motor (according to the description above) and not a four phase as mentionned in the caption.--Olivier.rieux (talk) 14:40, 15 June 2010 (UTC)

Someone add images and animation
Contact owner of this website to add these photos?

How to build stepper motors. http://www.aerodesign.de/peter/2001/LRK350/LRK350-20-15_eng.html http://www.aerodesign.de/peter/2001/LRK350/Warum_dreht_er_so_eng.html#Anker1164462

--Ericg33 (talk) 03:01, 6 July 2011 (UTC)

Clarification of the concept phase needed
In order to understand the contents of the third paragraph, clarification of the concept phase in the context of stepper motors is needed. The explanation is based on this concept and thus requires the user to first figure out what it is elsewhere. Blecchi (talk) 10:15, 1 December 2013 (UTC)

== Title error of section "wave mode" (there are two full stepping modes, the first one most likely addresses a different topic "wave mode" - as mentioned in the text"

Detent torque
It says "remnant". Does it mean remanent? 213.160.127.250 (talk) 14:29, 14 April 2014 (UTC)

Applications
I believe that stepper motors are commonly used in the analogue indicators of speedometers in modern motor vehicles. (I recently read a report, not on the internet, by a police crash investigator who has done research on the effect of crashes on these). This application is not mentioned on this page, and there is no mention of stepper motors on the "Sepeedometer" page either. Sorry but I don't know any more about this. Is there someone out there who does, who could add a biref mention in both this page and the speedometer page? Thanks --86.160.153.66 (talk) 12:56, 24 February 2015 (UTC)

Some of the applications are nowdays quiet obsolete. How many persons borns after 1990 knows what i floppydisk is?82.209.141.187 (talk) 07:56, 11 June 2022 (UTC)

Flange
I suspect that we are all agreed about the meaning of the term, and how it relates to one of the common ways in which most types of electric motor (DC brushed or brushless, AC induction in particular) may be mounted. However the "Flange" Wikipedia article does not mention motors at all. The omission is larger than this one article. I am suggesting that someone more experienced than me decides how to implement the necessary improvement. For instance, should every relevant motor article have a mention of mounting arrangements? (These would include foot mounting, often where chain or belt drive is used, flange where direct drive is used and axial alignment is fairly critical, or "servo" where small clamps engaging a groove are used, but there is a registration diameter on the end of the motor, like flange mount, to centre it accurately in its location.) There are almost certainly a range of other mounting styles of which I have no knowledge, hence my desire for someone else to fix this.

Tiger99 (talk) 21:04, 4 November 2018 (UTC)

steppr use
i think stepper motor can also use as a vibrator, vibrational motor for capping bottle or shifting of any object from its container  — Preceding unsigned comment added by 27.61.157.253 (talk) 02:29, 13 December 2018 (UTC)

Full-step drive (two phases on)	- Unclear
I don't understand why the latter part "Wave drive and single phase full step are both one and the same, with same number of steps but difference in torque." is in this subsection that is about full-step drivings. It makes this subsection uncleared.

Maybe it should be moved to the subsection above regarding wave drive. This senttence is also a bit unclear, so maybe also add some clearence to it. HenrikBorg (talk) 14:37, 7 August 2019 (UTC)

Animation
Currently given animation is increasingly oversimplified. AXO NOV (talk) ⚑ 18:12, 26 July 2022 (UTC)