need help on configuring new thermistor November 01, 2018 03:09AM |
Registered: 8 years ago Posts: 338 |
Re: need help on configuring new thermistor November 01, 2018 03:35AM |
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Re: need help on configuring new thermistor November 02, 2018 12:13PM |
Registered: 8 years ago Posts: 338 |
Re: need help on configuring new thermistor January 15, 2019 03:17AM |
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Re: need help on configuring new thermistor January 15, 2019 07:25AM |
Registered: 8 years ago Posts: 338 |
Re: need help on configuring new thermistor January 15, 2019 08:43AM |
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Re: need help on configuring new thermistor January 16, 2019 02:47AM |
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Re: need help on configuring new thermistor January 16, 2019 03:02AM |
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Re: need help on configuring new thermistor January 16, 2019 05:26AM |
Registered: 8 years ago Posts: 338 |
I wrote that I found the values. Of cause from the page you guided me to.Quote
But if you know that it is a 104GT2 thermistor, you can just use the values given on the wiki page
Re: need help on configuring new thermistor January 16, 2019 06:55AM |
Registered: 6 years ago Posts: 1,007 |
Re: need help on configuring new thermistor January 16, 2019 08:24AM |
Registered: 8 years ago Posts: 338 |
Re: need help on configuring new thermistor January 16, 2019 01:22PM |
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Re: need help on configuring new thermistor January 17, 2019 01:25AM |
Registered: 8 years ago Posts: 338 |
Hm, I don't know, what to use to hold liquid at 300° or more - no, not my way!Quote
To determine the thermistor specs, you have to remove it from the hot end, attach it closely to your T° probe and dip both in liquid, oil for ex. that you heat at different T° and compare.
Re: need help on configuring new thermistor January 17, 2019 08:23AM |
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Re: need help on configuring new thermistor January 17, 2019 09:02AM |
Registered: 6 years ago Posts: 1,007 |
Quote
dc42
PID control can't work faster than the dead time of the heating system. If you have run heater tuning, then the tuning process will have reported the dead time that it measured, and you should have copied this into the D parameter of the M307 H1 command (and copied the A and C parameters too).
You can attempt to speed up the PID response by reducing the D parameter in case the value measured by heater tuning was higher than actual, but if you set it too low then the temperature will oscillate.
Going back to the original question, if you want to adjust the thermistor reading at high temperature to match your thermometer reading, you can do live adjustments of the B parameter by sending M305 P1 Bxxxx where xxxx is the new B value you want to try. Make small changes, e.g. 1% or 2% at a time. When you have found a B value that works, put it in the M305 P1 command in config.g.
Re: need help on configuring new thermistor January 17, 2019 10:11AM |
Registered: 8 years ago Posts: 338 |
I measure the temperature touching the outside of the nozzle.Quote
The point is that what he measures is not the T° the thermistor is exposed to.
M305 P1 T99962 B4810 C6.7e-8
Ok, that's a point, I understand.Quote
PID control can't work faster than the dead time of the heating system.
Heater 1 model: gain 361.7, time constant 213.2, dead time 5.5, max PWM 0.60, calibration voltage 24.1, mode PID, inverted no, frequency default
Heater 1 model: gain 399.6, time constant 139.5, dead time 11.0, max PWM 1.00, calibration voltage 24.1, mode PID, inverted no, frequency defaultso shorter time constant means longer dead time?
Hm, don't understand this.Quote
You can attempt to speed up the PID response by reducing the D parameter in case the value measured by heater tuning was higher than actual
Heater 1 model: gain 399.6, time constant 139.5, dead time 11.0, max PWM 1.00, calibration voltage 24.1, mode PID, inverted no, frequency default Computed PID parameters for setpoint change: P5.6, I0.144, D43.6 Computed PID parameters for load change: P5.6I changed the commands in config.g to:
M307 H1 A399.6 C139.5 D11.0 S1.00 V24.1 B0 M301 H1 P5.6 I0.144 D43.6
Re: need help on configuring new thermistor January 17, 2019 02:07PM |
Registered: 10 years ago Posts: 14,672 |
Re: need help on configuring new thermistor January 17, 2019 11:11PM |
Registered: 8 years ago Posts: 338 |
Thanks for the hint!Quote
Remove the M301 command form config.g
Re: need help on configuring new thermistor January 18, 2019 02:56AM |
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Re: need help on configuring new thermistor January 18, 2019 04:01AM |
Registered: 8 years ago Posts: 338 |
You're kidding - aren't you?Quote
Dead time is measured in seconds
Re: need help on configuring new thermistor January 18, 2019 07:28AM |
Registered: 10 years ago Posts: 14,672 |
Re: need help on configuring new thermistor January 18, 2019 11:19AM |
Registered: 9 years ago Posts: 465 |
Re: need help on configuring new thermistor January 18, 2019 01:45PM |
Registered: 6 years ago Posts: 1,007 |
Quote
SupraGuy
I understand the confusion. This seems to be one more case of a term used elsewhere that's different for this application. (If you've been around a while, you'll see lots of ... discussion about the term "jerk.")
When I saw the term "dead time" my first thought was the same as yours, but since we aren't dealing with AC waveforms, or switch-mode power, I had assumed that once again, we're dealing with something else. It does make sense that there is a delay between when you switch on the heater and the thermistor (thermocouple, PT100, PT1000, or whatever temperature sensor you're using) starts to warm up, and if stable temperature is desired, you need to know what this is.
Re: need help on configuring new thermistor January 19, 2019 12:04AM |
Registered: 8 years ago Posts: 338 |
Thank you for the explanation.Quote
The dead time is determined by the heater cartridge, heater block and thermistor, not by the processor. Think of it as the time taken for heat from the cartridge to reach the thermistor.
Re: need help on configuring new thermistor January 19, 2019 03:41AM |
Registered: 10 years ago Posts: 14,672 |
Re: need help on configuring new thermistor January 19, 2019 06:49AM |
Registered: 8 years ago Posts: 338 |
Just to ensure, that I got you right:Quote
You are right, the dead time should be constant.
Re: need help on configuring new thermistor January 19, 2019 04:42PM |
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Re: need help on configuring new thermistor January 22, 2019 01:20AM |
Registered: 8 years ago Posts: 338 |
That was not my question.Quote
Hot ends with very large nozzles and heater blocks such as the Super Volcano may need additional heating power to handle the high filament melt rate. Ordinary hot ends don't.
Re: need help on configuring new thermistor January 22, 2019 02:52AM |
Registered: 10 years ago Posts: 14,672 |
Re: need help on configuring new thermistor January 22, 2019 07:20AM |
Registered: 8 years ago Posts: 338 |