Tuning a hugely overpowered heater

Tryptamine

@jens55 That is why I want to limit PWM.
If I send a PWM of 0.25, neither the board nor the wires will be overpowered.

Stop trying to explain electronics to me, I did not ask for it.

Tryptamine

@droftarts Thank you so much for this qualified answer.
You were the only person here really helping me out.

I tried to fix a GCode issue and not to get moral advice from everyone.
And I find it condescending from all the others to put themselves in a position where they feel like they have the right to judge about me and give me commands i just have to follow.

We are all on eye level here. If you want to recommend something, do it like droftarts.
Give your recommendations, but do not impose them, and do not treat me as I am an idiot.

A smoker asks you for a lighter.
You can give a lighter or not.
You can give the lighter and tell them smoking is bad for them (which they probably know already)

But nobody in his right mind would not give a lighter and instead call them an idiot for smoking and start an argument about how stupid his decisions are.
"Oh you TRY to quit? Fucking quit now already! It is dangerous! You are stupid!"

You do the exact same thing only in another domain, and feel totally fine with it. Why so?

deckingman

@tryptamine said in Tuning a hugely overpowered heater:

@jens55 That is why I want to limit PWM.
If I send a PWM of 0.25, neither the board nor the wires will be overpowered.

Stop trying to explain electronics to me, I did not ask for it.

At the risk of encountering your wrath, we do need to explain PWM to you because I can assure you that the board and and wires will be overpowered regardless of what PWM value you use. PWM does not limit the current, it only varies the amount of time that current flows. i.e. the width of the pulse (which is the "P" in "PWM"). But it does not limit the amplitude of the pulse so you'll still be drawing nearly 7 Amps from a board that is only deigned to take 6 Amps.

dc42

@tryptamine also please bear in mind that a 12V heater run from 24V is running at four times (not twice) its intended power. So if it gets stuck on at full power, it will almost certainly melt the heater block. Then it will be free tom the hot end and may contact wiring, plastic or other flammable materials.

I can't see any reason why the S parameter in your M307 command would not be honoured. Please run M307 H1 from the console and check whether it reports the correct PWM limit.

PS - I just tried sending M308 H1 S0.1 and then heating the hot end on one of my printers. As expected, it heated slowly and could no longer reach the required temperature. So the M308 S parameter works for me.

jens55

@tryptamine said in Tuning a hugely overpowered heater:

do not treat me as I am an idiot.

Calling it as I see it .....

I am done with this subject.

droftarts

@tryptamine Has re-ordering the config.g, by putting the M307 H1 ... after the M950 H1 ... , fixed the PWM issue?

Ian

rexx

@droftarts could you explain why the M950 before the M307 changes and what it does or is not just the ordering and would this apply to a chamber>

droftarts

@rexx all heaters need a temperature sensor, so M308 is defined first. The M950 effectively defines the heater, and relates it to the temperature sensor that allows control of it. Before M950, the heater doesn’t exist, so an M307 earlier than M950 that references the same heater applies settings to a non-existent heater. I believe when heaters are defined without M307, they are configured with the defaults for a hot end heater. If you then define the heater as a bed with M140 or chamber M141, these should come next, and I think alter the heater settings to defaults for each. Then set temperature limits with M143. Lastly, set the actual heater parameters you want with M307. This is the order the configuration tool sets, too.

Ian

rexx

@droftarts thank you kindly

Cheers

zapta

@tryptamine said in Tuning a hugely overpowered heater:

I am trying to get to work a 12V heating cartridge on a 24V system.

With 24V do get x4 the power so may need some creating solution. Since splicing the wires for a 24V heater or having a small 12VDC power supply are out of question, have you considered using water cooling to take away x3 of the power?