I asked a bit on other threads but thought it deserved its own topic. Can anybody explain the difference between a 5 pole motor and a coreless motor? Which is better? Or is there not much of a difference?
I am not an expert but I remember a tiny bit from my junior high science and engineering class. Maybe that will make my explanation oversimplified enough that someone who really knows will jump in to straighten me out. As I understand it, an electric motor is made up of several electromagnets that are turned on and off as contact is made. One "pole" of the magnet exerts a magnetic pull to start pulling the rotor of the motor a certain direction. If that one electromagnet just stayed on, it would pull the rotor to one position and hold it there (like a solenoid). But the turning rotor moves the contacts so a different electromagnet comes on and pulls the rotor the next fraction of a turn. If you had an even number of electromagnetic poles, the rotor might tend to stop exactly on a balance point where the electromagnetic pole would pull exactly the same in both directions of rotation and the rotor would be stuck until something pulled it off dead center. So motors are designed with ODD numbers of poles. At least one of three "poles" will be somewhere away from the "all things are equal" point and allow the rotor to start turning. Five poles are slightly better than three in getting a smooth turn. I imagine the three poles vs five poles makes much more difference in starting and in slow speeds, than in high speed continuous running. I think the question of core versus coreless motor is a different issue. It is like comparing red sports cars and blue trucks. A sports car might be either red or blue, and a red vehicle might be a sports car or a truck. Better comparison might be diesels or black locomotives. Which is more appropriate for your railroad? Steam locomotives may usually be black but blackness does not necessarily tell you whether a locomotive is steam or diesel. Conversely, knowing whether it is steam or diesel does not necessarily tell you whether it is drab black or colorful multi-hue. An advertisement or catalog listing or specification might list one element because that is the "hot" or "selling" term at the moment, or within some price range, but I think they are two different issues. So it is not an issue of one of the other. Now, somebody come along and tell me if this makes sense. Oh by the way. Some post writers do a poor job of writing a title that explains what the topic is. Your topic "difference between motors?" is a good, brief title that tells what it is about but stays a bit open to solicit useful though not necessarily anticipated responses.
This should clear it up for you: http://www.solarbotics.net/starting/200111_dcmotor/200111_dcmotor2.html
Thanks for the info guys. Chris, that web site is just what I was wanting. Very straightforward and visual. The pictures really help. By the way Chris, I often visit the Atlas site and must say you do very very fine work. Perhaps we can get you bit by the Z bug?
Well, by all means, post some pictures, if you have any! Because so many of the Nn3 ideas translate to Z I am always interested in what the Nn3 crowd has done. If your work Nn3 was anything as good as what you did with the Atlas/micro-ace mogul in N I am sure people here would enjoy seeing it! Thanks again for the info.
