Using Tic T500 to control closed loop stepper, getting low RPM

Hi,
I am trying to use a Tic T500 to output step and direction to an ebay nema 23 4amp closed loop stepper, the input is an analogue joystick, the motor runs but no faster than about 15-20rpm, it doesn’t seem to matter what my max speed or target is beyond a very low value, I have set the motors resolution to its lowest setting.
I wonder if anyone has a solution? I noticed a post from someone trying to drive a leadshine servo having the same issue.
Cheers!

Hello.

Have you followed the instructions in the Setting up analog speed control section of the Tic Stepper Motor Controller User’s Guide?

Could you post more details about your setup? In particular, your Tic settings file would be helpful. You can save the settings file by selecting the “Save settings file…” option within the “File” drop-down menu of the Tic Control Center, while the Tic is connected. Links to the specific stepper motor and additional stepper motor driver you are using would be helpful as well.

Brandon

Hi Brandon,
Thanks for your help!

Just to outline the setup; I have the gnd, step and direction connected to this motor the motor is set to 800 steps/rev (although I have tried other speeds) and the T500 is currently set to 1600 pulses/sec. I’m running everything on 24V.
The pot is being read clearly and the status is saying an output of 1600 pulses/sec when the stick is fully forward or back. The strange thing is the motor is running very smoothly, with nice acceleration and deceleration, although I only have fine control for a little bit around the deadband, beyond that it just runs smoothly at a constant speed of about 1 rotation every 4 seconds.

I’ve attached the config

Cheers!
Mohan

I’ve closed loop tic_settings.txt (1.3 KB)

Thank you for the additional information. I do not see anything obviously wrong in your settings. You might take a closer look at the STEP pin output of the Tic controller with an oscilloscope to make sure it is outputting what you expect.

That stepper motor and controller combination looks like it can accept a few different types of inputs; what connections are you making? Do you have any information about using the different interfaces supported by that controller (e.g. a datasheet or user’s manual)? I suspect that it is expecting differential signals, and you might need to make some additional connections to make it work correctly with the 2-wire STEP and DIR output from the Tic. For example, you might need to ground the negative logic pins on the controller.

Brandon