Jerky stepper motor problem

Hey everyone,

I'm using the stepper driver V1.2 with Keling KL23H51-24-08B steppers.
I've been having a hard time getting the steppers to run smoothly. I've followed the instructions on the wiki, and have wired everything up correctly (to the best of my knowledge...), but whenever I run the stepper tester program, the steppers won't rotate smoothly - they just vibrate. I tried swapping the polarity on one of the coils (switched A with , but to no avail.

At first I thought the issue was because we made our own circuit boards, so I purchased a stepper driver kit from MakerBots to compare. However, I tried to run a stepper with that and it still gave me the same problem. I've looked through the forums here and I read that the problem may be that it's getting too much current, so I tried adjusting the current, but I couldn't find a sweet spot (maybe the sweet spot lies in a very narrow range?).

Does anyone know what could be causing this problem, and how I could fix it?

Much appreciated,

--Aaron

Do you mean they don't rotate, i.e. just vibrate on the spot, or do they rotate in a jerky manner?

If the former try a lower speed. If the latter try a higher speed. Stepper motors do rotate in a jerky manner at low speeds, i.e. they move in discrete steps. They only move smoothly at high speed, or when driven with a micro-stepping driver.

---

[www.hydraraptor.blogspot.com]

The current to make a stepper work doesn't really have a sweet spot. Too low and it will stall, too high and it will get too hot. With the 1.2 driver board though you can set the current too high for the chip, in which case it overheats and shuts down.

Also the adjustment is over a very small range of the potentiometer, the first one fifth gives 0-2A. I.e with vRef set to 1V you get 2A. I would set it to 0.5V, i.e. 1A as a starting point.

---

[www.hydraraptor.blogspot.com]

Hi guys

Another little problem I ran into: have you checked the coils for conductivity? If one of them's broken things won't go too well...

Good luck

jbb

Yes the symptom of one coil not connected is that the motor vibrates on the spot, but at certain step rates it rotates in a random direction. If you spin it the other way it will reverse. It actually functions as a synchronous AC motor.

If you are using bipolar serial or parallel, having one of the pairs of coils that are wired together the wrong way round would probably have a similar effect.

---

[www.hydraraptor.blogspot.com]

Are the drivers getting hot? I ended up with big heatsinks on my driver chips.

---

---
Reprapping blog and other rants: [renoirsrants.blogspot.com]
My Reprap: [sites.google.com]

I found out what the issue was; the wire colors on the motors I bought were inconsistent with those on the datasheet (despite it being the correct part number), so the wiring was all wrong...well, that's fixed now.

--Aaron

I'm having the same issue. What was the solution(correct wiring)?

I think I have the same issue. Same motor and board. When I tested each board I got them to work OK but when trying to move in the software I can only get the small movements 0.1mm and 1mm to work 10mm is very problematic. How do I tune the stepper pot? Do I just turn the pot till the stationary humming is the lowest.

Dear Friends,
Recently i have beeen facing a problem on Stepper motor controlled by a Berger drive ,everyday in morning time when the machine is switched on the motor just vibrates and doesnt lift the axis after a littel movement the axis just falls down. Will it be problem of the drive or the motor. I will be chjecking the windings tommorrow, if anyone can guide me please do send your feedbacks.
Thanks

Dear friends,


I have machine in which two hybrid stepper motor are used i.e z-axis motor( for vertical movement) and theta motor ( for clockwise and anticlock wise movement) . this machine controlled by totally cpu board and motor drive board.

this machine works 3 to 4 hours very well and vertical movement of motor also work well but theta motor for rotation movenment works in jerky manner and move slow,.sensor of this machine for positon detection also work well .

Finally , machine works for 3-4 hours, in last robotic arm stuck or stop at rotor movement at any position.

plz advise me, whether its motor is faulty or cpu board.


Thanks