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nobody

20 Iun 2010 13:46



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Daca este vorba de o miscare relativ constanta lucrurile se simplifica fata de CNC. Adica ai cuplu minim cu acceleratii minime. Si nici nu ai nevoie de o pozitionare exacta ci de un sincronism intre timp si miscare.
La ce viteza si ce rezolutie vrei sa ajungi ?

Pentru a depasi limitele erorilor mecanice este nevoie de un feedback.

Solutia cu direct-drive si microstepping nu cred ca ofera avantaje la capitolul rezolutie:

While microstepping appears to make running at very high resolution possible, this resolution is rarely achievable in practice regardless of the controller, due to mechanical stiction  and other sources of error between the specified and actual positions. In professional equipment gearheads are the preferred way to increase angular resolution.

Step size repeatability is an important step motor feature and a fundamental reason for their use in positioning. Example: many modern hybrid step motors are rated such that the travel of every Full step (example 1.8 Degrees per Full step or 200 Full steps per revolution) will be within 3% or 5% of the travel of every other Full step; as long as the motor is operated within its specified operating ranges. Several manufacturers show that their motors can easily maintain the 3% or 5% equality of step travel size as step size is reduced from Full stepping down to 1/10th stepping. Then, as the microstepping divisor number grows, step size repeatability degrades.