Ring shaped cooling fan mod for davinci for universal hotend mod
ring was found https://www.thingiverse.com/thing:1620630 printed at 1.1 scale.
https://www.thingiverse.com/thing:447903 mounting bracket from here.
bolt in replacement hotend was from ebay. description. though it only likes to be put in and taken out from the right hand side of the carridge. fan was tied in with existing fan seems to run both ok underpowered.
Universal Hotend 3D Printer w/MK10 nozzle f/MK8 MK9 extruder most Extruders
had to use other thermistor settings repetier thermistor table 5 and 50 both worked for turning off the fan while when cooled, i print PLA at 1.4 x 160= 224 on the value chart which is about 140 deg C hopefully i can get that lower yet to reduce the smell.
NTC 3950 Thermistor
also goto menu -> settings -> bed coating and set the custom height to 22.50 , press < then save eeprom(wait 5-10 seconds before reboot printer so it saves to sd card). should be in the ballpark when you calibrate z , turn motors off and mobe the head around to see if it clears the platform.
im still using my old one so try at own expense. its offset to the right so the ring wont hit the heatbed.