# Change Nozzles Without a Restart **URL:** \ **Category:** Features\ **Created:** [January 16, 2023, 1:37am UTC](https://klipper.discourse.group/t/change-nozzles-without-a-restart/5964 "2023-01-16T01:37:15Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![garethky](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/garethky/32/956_2.png) [@garethky](https://klipper.discourse.group/u/garethky)\ **Post date:** [January 18, 2023, 4:14am UTC](https://klipper.discourse.group/t/change-nozzles-without-a-restart/5964/4 "2023-01-18T04:14:33Z")
Yes, that math is sound, I didn’t mean to make it sound like it wasn’t. Kudos again on grabbing the value out of the printer. I’m hoping since you did that you might be interested in this extension or merging this functionality into klipper itself. I welcome your feedback. I was trying to explain about the `max_extruder_cross_section` value. I’m adding that to the `printer` object as well and I think that has value in understanding how much your printer can extrude before it throws the “[Move exceeds maximum extrusion](https://klipper.discourse.group/search?q=Move%20exceeds%20maximum%20extrusion)” error. [This is a solid explanation that has the math right](https://klipper.discourse.group/t/h-move-exceeds-maximum-extrusion/1189/2) I was hoping that showing this calculation in Fluidd might help people understand what the enforced limits of the printer actually are. Maybe we could say something like one of these: - The maximum line width of a 0.3mm layer is 2.1mm (0.64mm²) - For a 10mm extrusion move the maximum extrusion length is 8.8mm (0.64mm²) - To extrude at the estimated extrusion rate of 12mm³/s the toolhead must move faster than 18.75mm/s (0.64mm²) They are all a bit alien vs how the slicer explains things but they are the real limits of the printer. --- _[View the full topic](https://klipper.discourse.group/t/change-nozzles-without-a-restart/5964)._