Mixing nozzle size in single print ?  

RE: Mixing nozzle size in single print ?

It’s not practical to change nozzles within a single print. You would never be able to get the height accurate enough. The only way would be a multi extruder setup with either 2 extruder or some form of tool change system. 

Theoretically you could slice the same model with 2 settings and then manually edit the gcode files so that the first print was with your larger nozzle but stopped at the transition height. Then you would have to do a full nozzle swap, recalibrate the height and z height, without using the print surface that had the first part on. Then you would start the second print off, which would move to the correct height (hoping that the mesh levelling using a second sheet was perfectly aligned with the first sheet, which is unlikely) then it would carry on printing. 
Of course you also have to hope that when the first sheet cools while you are doing the change doesn’t pop off the print. Basically you would have to go to massive effort to do with very little hope of success. Weight the possibility of having multiple failed prints with the time just printing the model with the smaller nozzle. 
Basically unless you are a glutton for punishment I wouldn’t bother. Even the machines with dual extruders often have issues as getting them synced up is difficult.