You might also like to take a look at my blog entry [miscsolutions.wordpress.com]. I describe using the Duet+X4 to control a dual nozzle Ormerod. There is a design issue with the X4 that causes a lot of noise on the temperature readings for the thermistors connected to the X4, and I describe a modification to eliminate it - although it's possible to print without the modification.
You will find a lot of discussion of the Duet and its firmware on the Ormerod section of this forum.
You will find a lot of discussion of the Duet and its firmware on the Ormerod section of this forum.