I am a bit behind due to trying to get my EMAIL machine upgraded to a newer model I received as a hand me down. The on board video stymied every distribution except puppy! I eventually was given an older PCI-X video card that allowed me to install main stream distros, and now I've pretty much caught up with this list.
Now to my comment. I think stepper motors are getting a bad rap when it comes to missed steps. Let's say you have a motor capable of putting out 500 oz-In of torque, and you are using it with a big dull shell mill. When the machine requires more than the 500 oz-in the motor is capable of putting out, the encoder lets you know that you are behind, and the machine stops. Your part may be scrap. The thing that is being missed here is that I didn't mention if the motor is servo or stepper. With either technology you still have to stop and correct your original problem (put a fresh shell mill in, or take a smaller cut.) The difference is that with a servo motor the machine constantly determines what level of oomph the motor needs. With a stepper motor the portion of a full step that the system gets behind determines the amount of torque applied to the load. If either are asked to put out more than they can, the system should stop. On 03/31/2012 03:20 PM, Dave wrote: > My experience with steppers is that once you lose sync with the rotor at > speed, you have to slow down tremendously to regain sync with the rotor. > So once you start slipping, you are pretty much done as you have lost > control of the motor. I don't see how using encoders with steppers > really helps other than detecting when you have lost control of the motor. > > Dave ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
