We used to sell the Redsail machines many years ago. From memory, the M700 and M500 lasers from Redsail are driven directly in the X and Y axis without reduction belts. This means the X and Y stepper drives should have the same dip switch settings (the micro toggle switches on the motor drives, between the two connectors).
If these are identical, check the Vendor param/ step length(um) values. Again, the X and Y axis values should be the same (or almost, as belt tension stretch may mean that the values need tweaking a little to get accurate results).