[jaru-eri]

I bought some used 6 wire unipolar stepper motors on Ebay and mounted them on bipolar drivers, but I can only run them on low speed.

I have set the drivers on 8 micro steps. Will they do better if I change this to 4 or 2 micro steps? Or will it be better for me to buy bipolar motors or maybe unipolar drivers?

Are there any way I can test the motors? Maybe the guy sold me some bad junks which has been overheated.

[johnmac]

What voltage are the motors? What voltage are you running them at? Are they stalling? More details on your setup will help a lot.

John

[Zappautomation]

Details on the motor and driver will help.

If the inductance is high on the motor, you will need lots of volts to get them spinning.

I bought some used 6 wire unipolar stepper motors on Ebay and mounted them on bipolar drivers, but I can only run them on low speed.

I have set the drivers on 8 micro steps. Will they do better if I change this to 4 or 2 micro steps? Or will it be better for me to buy bipolar motors or maybe unipolar drivers?

Are there any way I can test the motors? Maybe the guy sold me some bad junks which has been overheated.

[jaru-eri]

I use cnc_box 3977 and I think I need to adjust the current. There is also an attenuation mode setup that allows me to choose between 3 options, see picture:
Which of these three should I choose? And how much current do I need for full coil connection on the steppers? My drivers can get up to 2.5A My motors is unmarked, but hey are nema23 and I think the full torque must be at least 200 oz-inch. I use 24 V on these.

[Zappautomation]

What speed are you getting? Without the data on the motor it is hard to say what speed you should be getting.
Does the motor get hot?
you are making your own driver?

I use cnc_box 3977 and I think I need to adjust the current. There is also an attenuation mode setup that allows me to choose between 3 options, see picture:
Which of these three should I choose? And how much current do I need for full coil connection on the steppers? My drivers can get up to 2.5A My motors is unmarked, but hey are nema23 and I think the full torque must be at least 200 oz-inch. I use 24 V on these.

[jaru-eri]

The driver is cnc_box 3977 See: http://cgi.ebay.com/ws/eBayISAPI.dll...:X:RTQ:US:1123

I can´t set the speed to more than 20-30 inch/min before the motors halt. The motors don´t get hot but I think the current potentiometers on the drivers must have been pre-adjusted to the half, so maybe that´s the problem.

[Zappautomation]

20-30 inch a minute? What is this in RPM of the motor? what is the lead of the screw?

The driver is cnc_box 3977 See: http://cgi.ebay.com/ws/eBayISAPI.dll...:X:RTQ:US:1123

I can´t set the speed to more than 20-30 inch/min before the motors halt. The motors don´t get hot but I think the current potentiometers on the drivers must have been pre-adjusted to the half, so maybe that´s the problem.

[Zappautomation]

if the current is only half what the motors need then you will only get half the torque so that would make a differnence.

[pminmo]

Ahh, six wire motors...see, make sure you have your current set correctly, a common mistake:

http://pminmo.com/six-wire-motors

http://pminmo.com/which-stepper-motor

Rapids will depend on screw and load also:

http://pminmo.com/mechancial-power