I use brushless motors in my tank-And it seems to work well: https://www.youtube.com/watch?v=-MlTcjFC61E And nobody can beat the price-http://www.hobbyking.com/hobbyking/store/__8490__Turnigy_4258_Brushless_Motor_800kv.html?strSearch=4258
Den onsdag den 29. juli 2015 kl. 22.04.24 UTC+2 skrev RocketMan: > > >> Presumably, that rating is for a 100% duty cycle > This is my understanding, too. > > Thanks for the responses, everyone. I think I'll stick to brushed motors > for now. Frank's points make a lot of sense to me. One more thing that > concerns me about the outrunners is that most of the housing I've seen are > open. That's good when you're flying a plane and want to use the air flow > to cool the motor. It's bad when there's dust and dirt everywhere and Will > is trying to shoot paint up my tank's ass ! > > - Doug > > > -----Original Message----- > From: rctank...@googlegroups.com <javascript:> [mailto: > rctank...@googlegroups.com <javascript:>] On Behalf Of Frank Pittelli > Sent: Wednesday, July 29, 2015 3:09 PM > To: rctank...@googlegroups.com <javascript:> > Subject: Re: [TANKS] Re: brushless motor questions > > I haven't looked at brushless motors in detail, but from a couple years of > Physics in college I learned that when you increase voltage/current in a > coil, you increase the strength of the magnetic field generated by the > coil. So, I suspect that the "RPMs per volt" rating for brushless motors > tells you how much voltage needs to be applied to pull the armature hard > enough for a given speed. Presumably, that rating is for a 100% duty cycle > (i.e., max speed). Indeed, the controller pulses the voltage for two > purposes (a) to spin the motor one way or another and > (b) to regulate the speed (i.e., decrease the average voltage seen by the > coil). > > With regard to torque, for a given duty cycle, if you decrease the input > voltage the torque will also decrease. But, if you maintain the same input > voltage, while decreasing the duty cycle, the torque will remain relatively > stable while the speed decreases. That's why really big earth movers and > locomotives use diesel-electric drive systems ... > maximal torque across a range of RPMs. > > On 7/29/2015 12:18 PM, TyngTech wrote: > > Can't say I truly understand the brushless nomenclature (i.e. KVA) > > because nobody ever talks about the controller side. Brushless motors > > are basically steppers and without the controller are inert chunks of > > iron and copper. What I don't get is the KVA ratings (rpm's per volt) > > of these motors. In my mind, the controller dictates rpm by how fast > > it is energizing the phases, not by how much voltage is being applied. > > Voltage would affect acceleration and torque or am I getting this > wrong? > > -- > -- > You are currently subscribed to the "R/C Tank Combat" group. > To post a message, send email to rctank...@googlegroups.com <javascript:> > To unsubscribe, send email to rctankcombat...@googlegroups.com > <javascript:> > Visit the group at http://groups.google.com/group/rctankcombat > > --- > You received this message because you are subscribed to the Google Groups > "R/C Tank Combat" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rctankcombat...@googlegroups.com <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > -- -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups "R/C Tank Combat" group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
