Re: Checking EBB motor voltage from Inkscape

Home Evil Mad Scientist Forums Egg-Bot Checking EBB motor voltage from Inkscape Re: Checking EBB motor voltage from Inkscape



Experimenting with the EBB board and “extending” my test program I discovered that the pulse output from the EBB is acting a “little strange”. When pulsing at a low rate the pulses stop briefly every 16th pulse causing the motor to “stop” briefly every 1.8 degree of rotation. Driving a camera pan head the stops can be easily seen in the video recorded. I reckon the “jitter” or stops also happens at higher motor speed.
Without access to a oscilloscope or logic analyzer it’s difficult to estimate the duration of the stops. For smooth operation I am assuming the spacing between the end of a “major step” and the beginning of next “major stap” has to be the same as a between micro-steps, Is my assumption correct?

When experimenting with different stepped drivers, motors and controllers it can often be difficult to figure out where the fault lies when the motor does not move as expected (sometimes it does not move at all!). Visiting different CNC forums over the years the need for a simple tester can be seen. Googling for a “stepper fault finding tool” came up with nothing so I set out with pencil and napkin and “designed” my own.
Result can be seen in this video snippet; Simple_Stepper_Driver_Tester.
The stepper tester is connected to the output of the stepper driver in parallel with the motor.
As can be seen in the video even the micro-stepping can be seen as varying intensity of the LED’s. (From approximately 0:30 when rotation changes to CCW) The micro-stepping can bee seen even better running the motor slower.
By removing power to the driver and rotating the motor (by hand) will cause the LED’s to light up if the motor is OK and wired correctly.
The (extremely complicated ;-) ) schematic for the tester will be uploaded as soon as I have translated “from napkin to PDF”.

Have fun.