Zero hotend upgrade on SV08 Max

To get this out of the way: I’m making functional parts, I seldom print below 300C, and it’s almost always PET-CF, PPA-CF, headed towards PPS-CF, although have recently been running it with PC-ABS and PC-CF (with the new chamber heater and the properly working insulated heat bed, the PET/PPA-CF don’t need the heated chamber as desperately as the ABS/PC filaments)

Finally ordered a Zero hotend for my max. (also ordered a complete zero extruder, but I digress)

Still waiting for both, but the extruder has tracking info at least.(from NY)

Was poking around in the config, seems to be an upper limit somewhere above 330C in Klipper on the std max, max temp set to ~360C gives klippers temp not in range error, not finding it in any of the config files, wondering if its coded into the extruder board firmware?

I understand keeping the temp down for the Max brass hotend (but brass should be fine to ~350C), the Zero hotend allegedly has a much higher copper % so 350C spec (originally 400C). I was in there so tried increasing it just to see if it worked…

Anyone know what (if any) files might be needed to reload the extruder board firmware? To use the Zero extruder? (or am I missing something?)

Unless I was totally misinformed, the MAX already has the ZERO hotend.

You even posted about it here:

Good question. The official Klipper configuration docs read:

max_temp:
#   The maximum range of valid temperatures (in Celsius) that the
#   heater must remain within. This controls a safety feature
#   implemented in the micro-controller code - should the measured
#   temperature ever fall outside this range then the micro-controller
#   will go into a shutdown state. This check can help detect some
#   heater and sensor hardware failures. Set this range just wide
#   enough so that reasonable temperatures do not result in an error.
#   These parameters must be provided.

I read this as the maximum temperature is dynamically written to the MCU at initialization. I could be wrong and a “safety limit” could be inserted when the MCU firmware is compiled.

I don’t see a way to set it in the klipper build process

i asked. max has brass version zero has copper version. supposed only difference is hot end material. max tated to 300c, zero to 350c. i run max hotend at 320c for momths no issues , use tq wrench on nozzle swaps. will do same after upgrading. the real ypper limit for the zero is likely the ceramic heater, they lose efficiency hard over 300c.

I was able to get around it, it didn’t like me increasing the top end value for the sensor curve, but lets me exceed it fine, which seems odd. Wanted to use higher measured value for better accuracy at 400C. Still beating on it as I want to understand issue…

The following works. The commented out section borks Klipper.

[adc_temperature extruder_thermistor]
Temperature1:25
resistance1:1268.60
temperature2:180
resistance2:1920.98
temperature3:300
resistance3:2398.52

#[adc_temperature extruder_thermistor]
#temperature1:25
#resistance1:1268.60
#temperature2:270
#resistance2:2810
#temperature3:400
#resistance3:1760

[extruder]
step_pin: extra_mcu:PA8
dir_pin: extra_mcu:PA9
enable_pin:!extra_mcu:PA11
rotation_distance: 6.5
microsteps: 64
full_steps_per_rotation: 200
nozzle_diameter: 0.400
filament_diameter: 1.75
max_extrude_only_distance: 150
max_extrude_cross_section: 60
heater_pin:extra_mcu:PB7
sensor_type:extruder_thermistor
pullup_resistor: 11500
sensor_pin: extra_mcu:PA5
min_temp: 0
max_temp: 420
max_power: 1.0
min_extrude_temp: 190
control : pid
pid_kp : 34.838
pid_ki : 4.976
pid_kd : 62.823
pressure_advance: 0.025
pressure_advance_smooth_time: 0.015

Also be come more fragile. At some point the wire simply melts.

have considered using a pair of 65w ceramic heaters, one on each side, or a pair of the std (longer) 85w sovol units, but limiting to 70% or such for heat on both sides… the zero/max melt zone is certainly long enough.