50 WATT Heater Cartdrige on Volcano hotend Pid-tune problem

[sniper23]

Hi, I've got myself a new volcano hotend with 50-watt cartridge. The problem is that when I do write M303 H1 S270 it gets up to 310 degrees.

Basically, it can't give me a stable heating performance.

M307 H1
Heater 1 model: gain 1150.2, time constant 138.7, dead time 7.8, max PWM 1.00, calibration voltage 22.9, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P2.8, I0.084, D15.1
Computed PID parameters for load change: P2.8
15:55:19Warning: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 1175C.
Auto tune heater 1 completed in 179 sec
Use M307 H1 to see the result, or M500 to save the result in config-override.g

[deckingman]

@sniper23 What is even more of a concern is that the predicted temperature if left on at full power (as might happen if a MOSFET failed) is likely to reach 1175 deg C. Given that aluminium will melt at around 660 and brass at around 900, that's more than a little concerning. Might you perhaps have bought at 50W 12V cartridge which you are running on 24V? Measure the resistance of the cartridge if you can and post the result here.

[jens55]

I have had China ship me 24V heaters that were actually 12V heaters and yes, they shoot up real quick in temperature on 24V
I set up my 50W heaters with a 0.8 duty cycle to stabilize heat a bit more as 50W seems a bit high in my case (also with a Volcano). I have gone back to 40W cartridges for better even heat control.

[dc42]

@sniper23 said in 50 WATT Heater Cartdrige on Volcano hotend Pid-tune problem:

Hi, I've got myself a new volcano hotend with 50-watt cartridge. The problem is that when I do write M303 H1 S270 it gets up to 310 degrees.

That's normal when the heater is very powerful for the size of the heater block it is in. Have you measured the resistance of the heater, to calculate the actual power at the VIN voltage you are using?

Basically, it can't give me a stable heating performance.

In what way is the heating performance not stable?

[Veti]

not 100% applicable
but here are the values for the original e3d ones
https://matterhackers.dozuki.com/Wiki/E3D_Heater_Cartridge_Resistance

[sniper23]

@dc42 By not stable, I mean this one.

For example, I have set 220 degrees. But, it just doesn't stop there, it goes higher and because of 15c limit, heater faults.

[deckingman]

@sniper23 The reason for that overshoot is the same reason why the predicted fully on temperature would reach nearly 1200 Deg C. Have you measured the resistance yet?

[Veti]

@sniper23
just checking. how did you have the values from the pidtune?

[sniper23]

@deckingman I don't have tools to check resistance. After some more tweaking, there isn't a huge temperature space between reach and actual temperature.

Well, for now.

[deckingman]

@sniper23 If you can't beg, borrow, steal, or buy a multi-meter, I suggest you buy another heater cartridge from a reliable source that is guaranteed to be for 24V use. Looking at the model gain and the warning about predicted temperature reaching 1175 deg C, I strongly suspect that you have a 50 Watt 12V cartridge, and not a 50 Watt 24 V one.

[Veti]

@sniper23 said in 50 WATT Heater Cartdrige on Volcano hotend Pid-tune problem:

I don't have tools to check resistance.

you should get one. otherwise you can not diagnose a lot of problems

[sniper23]

@Veti Okay, after a lot of playing with values, it can finally stay in the reached temperature in a stable condition.

M307 H1 A759.9 C180.5 D8.3 S0.50 V23.3 B0

[Veti]

@sniper23 said in 50 WATT Heater Cartdrige on Volcano hotend Pid-tune problem:

S0.50

this would be a strong indicator that you have a 12V catridge

[denke]

@sniper23 If you drive an 50W 12V heater from 24V then it's actually 200W. Since you draw 8.3A from a circuit not designed to handle that (according to this 6.7A max: https://forum.duet3d.com/topic/1925/max-hot-end-heater-current/7) you can blow the mosfet easy. If you do that, or the duet fw freezes for any reason, then you'll probably have a fire on your hands caused by molten aluminum dripping on your printed part and other stuff. So, !!please!! stop using it and find out what you're dealing with before that happens!

[sniper23]

@denke I have fixed the issue, for now.

I use 24V, not 12V. I use a 220W power supply.