Testing a Budget 3D Printer Hotend Upgrade

This page documents the change in achievable volumetric flowrate (VFR) caused by upgrading a Longer LK5 Pro to a knockoff all-metal hotend+CHT nozzle from aliexpress.  A comparison of the fit of the two hotends is shown below:

Comparing the original hotend (left) and upgraded hotend (right) 

To compare the performance difference between the two hotends, a volumetric flowrate test was generated using the CNCKitchen/iFallUpHill benchmark tool at https://hotend-flow-tester.netlify.app/ and run on both hotends.

Testing the hotends with Elegoo Highspeed PLA yielded the following results:

The new hotend + CHT nozzle results in a modest increase in allowable max VFR of around ~20-30% depending on hotend temperature.  This is a somewhat lower improvement than expected, and could be due to the small meltzone of the hotend or the bowden tube setup of the LK5 pro.  The aftermarket all-metal hotend upgrade kit uses the Bambu hotend nozzle format, and this limits the total length available in the meltzone for the filament to come up to temperature.