Biến step motor 2 pha unipolar thành bipolar

[anhxco]

Đúng rồi bác ơi - MẤT TỪ - Tuỳ loại, em tháo cũng gần chục con có 2 con mất từ, nhẹ hều. 2 con sau cùng bị (hi hi, chắc là do đọc bài mấy bác).

Cái nì có vẽ đúng, mấy ông tây cũng thử rùi, mà phải tháo rời roto ra, chứ mỡ nắp đít nó ra vẫn tốt mà:
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From a post on the web (If it is on the web, it has to be true...). All kidding aside and references to old, young, husbands or wives tales be darn....

"Sorry, but that is absolutely NOT true. Stepper motors are very different from brushless DC motors, and WILL be significantly damaged simply by being disassembled, no matter how carefully it's done. Do some Googling, and you will see this is 100% true, and is very well known to those who work with stepper motors on a regular basis.

From Anaheim Automation:

"Q: Is there any damage caused by a stepper motor that is disassembled?
A: Yes! Up to 60% magnetizing loss can be the result if the rotor is pulled apart. If all parts are replaced properly, the motor can be remagnetized at the factory, but the charge is substantial. If you have a motor failure, or are concerned about the performance, contact Anaheim Automation. Please note that the warranty period is 12 months from the date of invoice. "

From ServoRepair.com:

"First, any time a motor is disassembled, there is a high probability that the magnets will be discharged to a point where the torque will be diminished. The results vary and may or may not initially be noticeable. With some motors, the results will be immediate. In fact, disassembly of a stepper motor will typically demagnetize the magnets to a point that the motor is useless until it has been properly remagnetized."

From Lin Engineering:

"Do not disassemble motors; a significant reduction in motor performance will occur."

From a post by Mariis Freimaniss, of Gecko, who knows as much about stepper motors as anyone in the world:

"This topic came up in another group. The stator acts as a magnetic "keeper" for the rotor.

Nothing like running an experiment to know if something is true or not.

I had a motor I didn't care for (MO62-FD04), so I ran dyno tests on it that showed 112 in-oz low-speed torque. I removed the rotor for 5 seconds, then replaced it and re-ran the dyno test.

The low-speed torque now was 70 in-oz, or only 62% of what it was before disassemby.

You may not notice the loss in torque but it is real and it is there.

Mariss"

Disassembly of a stepper motor WILL damage it! Guaranteed!"
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