Note on the new Bear extruder release (Patreon)

Hi everyone, we are really close to release the new extruder, we are reviewing and adjusting some links and doc. But there is an important point I want to share before.

The new original Prusa extruder has the hotend placed higher up on the X carriage, it creates a 7mm longer Z axis. Unfortunately, this new  feature makes the air around heatbreak and heatblock warmer and it could lead to the following issues:

• It could melt the bottom of the extruder body.
• It will reduce the efficiency of the heatbreak which could create several  issues: clog, heatcreep, inconsistency and longer retraction.
• It could make the part cooling less efficient.
• It makes the bottom of the X carriage more fragile. This might need a complete re-design of the X carriage back that would not allow anymore to be split in two parts. Which means you will have to disconnect all cables from the Rambo Mini/Einsy every time you want to change something  on the extruder.
• The bottom bearing of the X carriage on the stock extruder could wear quicker.
• Some people are experiencing damaged hotend cables due to the screw of the  heated bed cable cover (they have provided a fix to this recently).

To provide an efficient solution to those potential issues we have decided to keep the old position of the extruder on the X carriage. Unfortunately, the original MK2.5S/MK3S firmware is testing the length of Z axis during (XY)Z calibration and selftest so they will fail with  the Bear extruder. To solve this we have created a special firmware that  will be used ONLY for (XY)Z calibration and selftest. The assembly instructions will guide you easily through these steps to make sure you have a flawless experience with our extruder.

I would be very happy to hear your honest feedback about this approach.