Yes, usually treadmill DC motors are used for lathes, but those are unavailable here, and expensive to ship from places they are available:) Technically wound-stator motor with DC connected across it should be equivalent to permanent-magnet motor. But I'm not quite sure if it's that simple. On Thu, Aug 23, 2012 at 1:22 PM, Nily wrote: > As far I remember DC series motors are the best from torque point of view= .. > Today permanent magnet motors and PWM controllers, like those used in bik= es, > seem to be better than other options. > To your question, if you have a DC motor with coils, you can control its > field. Usually DC motors use simple magnets. I think it won't be easy and > cheap to control field and rotor. > > -----Mensaje original----- > De: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]En nombre de > KPL > Enviado el: Jueves, 23 de Agosto de 2012 01:55 a.m. > Para: PICLIST > Asunto: [EE] steering of universal motor > > > Hi, "world-wide brain" :) > > I am using an old washing machine motor to drive my small metalworking > lathe, using a very simple U2008- and triac-based speed controller, > which does not work too well. Lathe is not used too often, so I am not > going to invest lots of time or money in that, but anyway, I am > thinking of a better controller. > > I have checked several different appnotes and docs about universal > motors, and general conclusion is to use DC drive with PWM, which > should not be extremely difficult. > But I have not seen any docs that would talk about steering the field > winding separately from the collector. Lathe requires a lot of torque > at low speeds, so probably I could get some advantage with higher > current in field winding, when voltage on collector is low. > By default field winding is connected in series with collector, so it > gets less power, when voltage is reduced for lower rpm's. > Any thoughts? > > > -- > KPL > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 KPL --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .