Hi Tom

I have just received the kStep. Thanks for the prompt delivery to the UK.

I am using the four outputs to drive two pairs of small steppers which tilt a drilling head in two directions.

I connected it up with the lowest current settings (all current jumpers removed) and it all worked first time, thanks to your clear manual.

However, on the lowest current settings, there is not quite enough torque, and the motors are missing steps once in a while.

Unfortuantely, when I added the jumpers to go to the second lowest current setting, the steppers make a screeching noise, the current jumps to 2.99Amps and the voltage drops from 30 volts to 10 volts. At this point I rapidly switch off the power.

Other info: -

On the lowest current setting, the board is drawing 0.4 Amps at 30 volts, with all four motors connected.

I am also using a Kanalog.

The motors are Nema 17 bipolar with a holding torque given as 4.4 kg/cm, and a coil resistance of about 3 Ohms.

My initial thought is that the current limiter in my power supply is hitting 3 Amps and it is the behaviour of my power supply which is causing the problem, but is the jump from the lowest current setting (0.4 Amps in my case) to the next one (over 3 Amps) really meant to be so big?

I am also not clear if the Current values in your jumper table are per motor, or total.

I am nervous about connecting a power supply without current limiting without your advice in case I fry the board!

best regards

Edward

Hi Tom

Problem solved. It was the power supply. I was using a desktop lab type power supply. I am now using another power supply and it works fine

best

Edward

--- In DynoMotion@yahoogroups.com, "dotma99" <edward@...> wrote:
>
> Hi Tom
>
> I have just received the kStep. Thanks for the prompt delivery to the UK.
>
> I am using the four outputs to drive two pairs of small steppers which tilt a drilling head in two directions.
>
> I connected it up with the lowest current settings (all current jumpers removed) and it all worked first time, thanks to your clear manual.
>
> However, on the lowest current settings, there is not quite enough torque, and the motors are missing steps once in a while.
>
> Unfortuantely, when I added the jumpers to go to the second lowest current setting, the steppers make a screeching noise, the current jumps to 2.99Amps and the voltage drops from 30 volts to 10 volts. At this point I rapidly switch off the power.
>
> Other info: -
>
> On the lowest current setting, the board is drawing 0.4 Amps at 30 volts, with all four motors connected.
>
> I am also using a Kanalog.
>
> The motors are Nema 17 bipolar with a holding torque given as 4.4 kg/cm, and a coil resistance of about 3 Ohms.
>
> My initial thought is that the current limiter in my power supply is hitting 3 Amps and it is the behaviour of my power supply which is causing the problem, but is the jump from the lowest current setting (0.4 Amps in my case) to the next one (over 3 Amps) really meant to be so big?
>
> I am also not clear if the Current values in your jumper table are per motor, or total.
>
> I am nervous about connecting a power supply without current limiting without your advice in case I fry the board!
>
> best regards
>
> Edward
>