Heated Chamber

jonas

As i mentioned in https://forum.repetier.com/discussion/5642/heated-chamber-enclosure-housing#latest, operate a 3D-Printer with an heated Chamber is possible but quiet tricky.

I have some ideas for possible new Features which would make usage of a heated chamber much more easier.

#1
Implement the "FAN_THERMO_MIN_TEMP" and "FAN_THERMO_MAX_TEMP" into the EEPROM so it is possible to change the variables without reflashing firmware
(btw. in the configurator is a typo, it should be "°C" not "ms")

#2
As far as I'm aware the heated chamber is only implemented in "repetier-server"
Perhaps it is possible to implement it into the firmware too, but i have no Idea how it would be the best way.

#3
Or allow to adjust the heated chamber settings in repetier-server
Something like, i can set the temperature which already exists, but i can choose which extruder is used, which fan is used and i can define a acceptable temp. drift.
Like:
Set chamber temp. to 35°C with +-3° drift
1) Chamber is heated to 35°C
2) if temp. drops under 32°C the chamber is heated again
3) if temp. rises above 38°C the fan is activated

Perhaps it is is possible to implement one of this points in future updates, i already enjoy working with repetier.

Repetier

Heated chambers come with firmware V2.

No need to flash firmware for thermo controlled temperature

M460 X<minTemp> Y<maxTemp> : Set temperature range for thermo controlled fanallows changing the settings. But that is not a heated chamber. That is more to ensure a maximum temperature is not exceeded.

Having no heated chamber it is a bit of a problem to know what is needed but most seem to just have a heater that gets controlled normally combined with a fan to evenly distribute heat. If heater reports heater as C it is a heated chamber for server and server adds a temperature control using M141 to set temperature. I think in V2 it is even working, but V2 is not complete also already usable for some combinations.

Did fix ms->°C in dev version. Will appear in stable on next update.

MaukCC

Our setup for heated chamber is:

- a Heater

- a fan that blows the air into the chamber (preferably goes on when temp is set, goes to xxx% when temp is reached and off when temp is disabled)(done manually at present)

- a thermistor for the chamber

- a thermistor that disables the heater when the surrounding panels of the housing gets over 80 degrees, with hysteresis.(done with electronics at present)

You are welcome to come and check it out and do some testing. We are about an hour away in Maastricht.

Repetier

Ok I understand that you have a heater and a temp sensor for chamber controlling the heater. A fan is required to get even distribution in chamber. Makes sense.

What I'm unsure about is the housing thermistor. What is the sense here. Is it somewhere where chamber heats it up as well so to prevent additional heat at some safety point you disable the heater?

Sounds all like I can solve it with some heater modules in V2. I mean that is the main reason for the modules - to add some own logic like a sensor disabling a pwm for safety. Could e.g. mimic a pwm with thermo failsafe that sets a pwm to 0 if a second condition is met regardless of what the main controller wants.

MaukCC

Repetier said:

What I'm unsure about is the housing thermistor. What is the sense here. Is it somewhere where chamber heats it up as well so to prevent additional heat at some safety point you disable the heater?

Yes, correct, a safety procedure. We have an oven heating element of 1400W that goes to 400C. It is in free air but about 10mm from the housing plates. On the housing plates is a thermistor to measure the temp of the steel plates. If that goes over 80C it overrides the heater. This is also because we do not want the air that is being blown around in the chamber gets too hot.

jonas

sorry for my long absence

MaukCC already meantioned the problem

my heated bed produces too much heat during ABS printing, so i have to cool the chamber

my stepper motors are in the housing, so i want to avoid temperature over 40°C.

Therefore my setup which I mentioned in #3

Repetier

In that case use the thermo controlled fan to reduce heat in the chamber. You can have a low and a max temperature so it increases cooling affords on higher temperatures.