Hatchet's all up and running again after the whole *grubscrew eating the motor shaft* thing, had the sprocket welded onto a new motor (350w this time instead of 300) and that seems to have sorted it. Managed a little video, just to clear it up the axe doesn't actually hit the floor because it's travel is stopped by the front bulkhead about 5mm from the ground. https://www.facebook.com/video.php?v=346043228929766