Hi Everyone, I just finally wired up my CNC last night after I got my Blackbox. I already tested movement to make sure that everything was running in the correct direction and so far so good, the next step is to start calibrating the machine. This is something that I am trying to understand but haven't stumbled onto any documentation or videos yet but here goes. * Nema 23 * Manufacturer Part Number: 23HS30-2804S * Motor Type: Bipolar Stepper * Step Angle: 1.8 deg. * Holding Torque: 1.9Nm(269oz.in) * Rated Current/phase: 2.8A * Phase Resistance: 1.13ohms * Inductance: 5.4mH+/-20%(1KHz) 1. How do you know what to set the current rating for your stepper motors? 2. Regarding microstepping, how do you know what to set this to? I know the Blackbox has it set at 1/8 microstepping for better torque but what if I change motors to something else down the road. Appreciate any help on this.
docs:blackbox:microstepping [OpenBuilds Documentation] Factory default is good for most, if you need a little more, dial it in: docs:blackbox:currentadjustment [OpenBuilds Documentation] Plug and play man, it's setup to just work
No math involved. We made BlackBox to be "beginner friendly" Factory default is spot on for most of our machines and actuators - just plug it in and go. You very likely won't need to change anything Full anti clockwise is 1.2A, full clockwise is 4A. In between is a linear extrapolation - so for example, halfway between min and max = 4 - 1.2 = 2.8 /2 = 1.4 + 1.2 offset on the low end = 2.6A = factory default) Perfect for your 2.8A motors (2.8 is the maximum, not the recommended current setting)
I am going to upgrade my steppers to the high torque versions within a couple weeks, I see that the amperage is 4.2a for the high torque and the Blackbox only supports 4amps, am I still going to be safe and not burn out a driver?
Hi Salamander, Yes you will be good, you can adjust the current output on the BB. For the HT motors I would start with about 3/4 toward full power on the potentiometers. Cheers Gary
Our High Torque motors are 3A, so you aren't referring to ours here then? If you are running 3rd party motors, not ours, make sure other critical specifications like inductance and coil-voltage (calculated from coil resistance and current rating if not specified) are suitable as well. Ours are specifically chosen for optimal performance (3v coils, low inductance)
Thanks guys. I will have to look at the motors in the store here, after all everything is shipped pretty fast.
And perfectly matched takes out the risk The other motors may sounds more powerful, or cheaper, or whatever reason, but if, for example, their inductance is too high - you end up with disappointing top speeds, or the coil voltage is wrong and you have to dial in super slow acceleration. At least with ours you know we balanced the compromises best we can to make sure it all plays nice with every other component in our ecosystem
