It's a bit difficult to explain if you have no context.
Basically, I need this to go to 3 positions.
On startup it should go to 0
Then as part of the startup, run to 35 full turns and wait for 30 minutes. (This allows me to add or remove eggs without adding extra cost or code)
Then it should run to 70 turns, wait an hour, go to 0 turns, then loop forever.
This seems to work for a number of hours, then goes a bit wrong, hits hardware limits and shears couplers.
The PSU I'm using has 7A & 13A +12v rails (stepper is rated 1.68 12-24v) so I suppose there's room for more power there, but there's not a lot of heat coming out of anything, so it doesn't seem especially likely to be that.
I can't see it being an arduino power issue, as it'll self home on startup.