Machine: Scratch built
Firmware: Smoothie as shipped
Question: What controls the maximum speed for G0 moves?
I’ve got the X and Y axis of my build working. I have a 1305mm x 760mm bed and have the motors and homing all operating correctly. I want to determine the maximum speed I can move at but seem to be hitting some kind of limit (around 400mm/sec by timing with a stopwatch). In Lightburn the speed maxes at 1000 mm/sec in the Move tab so I upped the speeds in the config file to 60000 mm/min which should theoretically allow me to test up to the Lightburn limit of 1000 mm/sec. I’m issuing a G0 command in the console without a feed rate to test.
What I’m unsure about is how motor current might limit things. I’m using NEMA 17 motors (84oz/in / 2.0A / 27V) with external stepper drivers set at 1.5A, and I have the current in the config file also set at 1.5, although I don’t know if this has any bearing when using external drivers.
I’m not particularly unhappy with the speed, just trying to understand what limit I’m hitting. If it’s not in the config or the current settings then what about the actual mechanics of the build? Would the speed reach a mechanical limit without manifesting itself as a movement issue, (e.g. juddering, grinding, skipping steps, etc)? It moves quite smoothly, just not at the speed I expect and I’m worried that if it doesn’t move at the speed I have programmed for a job then it’s not going to give me the desired results.
I only just completed the Y-axis tonight so I’m going to do more thorough testing tomorrow. Any suggestions would be appreciated!