This instructable shows how to improve the accuracy and resolution of the plotter described in…The accuracy was improved by using: thick aluminium shoulder arms to prevent sideways flexing. metal sleeves at each joint to eliminate sideways movement due to the 3mm bolt threads. a light-weight gel-tipped ink cartridge (optional).The resolution was improved by a factor of 8 by: using a 4:1 step down belt drive to achieve more motor steps. using a controller that supports 16 times microstepping.”