I did more testing on this today since my new motors came in. The results I got were surprising, to say the least.
All acceleration testing was done using 2000 mm/min jog speed (limited by the GRBL max rate value)
Inventables stock stepper motor: 10,000 mm/sec^2 was the only value that I could ever produce stalling.
269 oz-in StepperOnline: 1100 mm/sec^2
270 oz-in Automation Technologies: 3000 mm/sec^2
I ended up upping my value to 1000, I think, and I’ll watch it. I did a day of carving at 750 this past week and had no issues. I’m now interested in what the max acceleration from a GRBL perspective is and if some values don’t play nice and cause calculation abnormalities (for instance at 3000 on the 270 is a stall but 4000 or 7000 worked just fine…)
Now, I also did some max feed rate testing on my linear slide. These were all with a 750 acceleration setting (accel changes max feed rate, at 2000 accel, the Inventables stepper achieved only 120).
Stock 140 oz-in stepper: 145 ipm
269 oz-in: 85 ipm
270 oz-in: 100 ipm
This really shows how well matched the Inventables steppers are to the machine and the lower DC voltage. These are also unloaded (nothing cutting) so I’d expect the Inventables to potentially drop quicker while under more load from plunging/cutting. This also really has me wanting to see torque curves of this motor as it’s gotta be pretty flat for that level of performance.
Based on this, and the minimal price difference, I think the Automation Technologies steppers are a better value. ~18% increase in max feed rate and much higher acceleration potential. They seem better matched. The one downside, the lead wires aren’t long enough to reach the terminals on the Xcarriage. I need to figure out how I want to remedy that.
I’m waiting for my new belts (staying at 6mm wide and 2mm pitch but going to 3rd gen belt) before I switch all my steppers out.
I’m willing to try more experiments because the results aren’t quite resonating yet.