CR hotend, modified

thingiverse

I must say again that the fundamental design by holyfarrier is truly exceptional. I started working with this design about three months ago and fell deeply in love with it after discovering that it achieves several key benefits for me: 1. Quick access to nozzle is achieved through rapid removal of fan duct. 2. Highly effective part cooling even at low PWM levels (I'm talking 10% fan levels) makes it very efficient, rendering the same old fan levels overkill and truly advantageous when optimizing part cooling. 3. Nozzle proximity to X gantry 2020 extrusion is ideal, unlike other designs that leave the nozzle further away than desirable, causing issues such as y-axis calibration problems. The least of these issues is a loss of about 7 mm on the Ender 3's total 230mm length with the stock Cr mod, whereas others take up around 15 mm or more. Here's a summary of my modifications: 1. I redesigned the interface between the fan duct and the drive mount by adding a photo of a PETG white printed fan duct with two bolts on its right side, but later found those bolts to be unnecessary and removed them. 2. Instead, I opened up the interface on the right side by a tiny amount to allow for the user to insert thin sheets to adjust the tilt of the duct nozzles once mounted, and also opened the interface on the duct to the left to increase rigidity, which helps with repeated handling. 3. I added a thru-bolt to secure the entire assembly. 2. I modified the clamp at the rear of the drive mount to increase its rigidity while adding cable chain attachment options, deciding to go modular so that the chain could be removed for maintenance and future modifications would be relatively easy. All bolts are M3 with M3 nuts. 3. I designed an X motor end cable chain mount, which includes a collet to hold in all necessary cables and a rear mount to force the component to sit flush against the X gantry motor mount plate. The rear mount requires M2 x 10 bolts, tapping is 1.5 or 1.6 mm for a good mount for M2 bolts.