1 Topic by cliquot22

  • cliquot22
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Topic: Thermister variability in E3D-V6 hot end

My temperature as reported by the thermister in my e3d hot end varies significantly.  It goes +/-3deg in just a few seconds.  I don't think it should be doing this.  Does this mean my thermister is bad or something else? 

I added a picture of the temperature profile. 

I'm using a printrbot simple metal with Repetier software.

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2 Reply by heartless

  • heartless
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  • Registered: 2015-04-08
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Re: Thermister variability in E3D-V6 hot end

you need to do a PID tune to get it stabilized.

do a search for it, there is plenty of discussion about it.

SD4 #1 & #2 - Lawsy carriages, E3D v6, Rumba controller board, mirror bed plate, X motor fan, upgraded PSU & Mica bed heater
SD4 #3 - in the works ~ Folgertech FT-5, rev 1
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3 Reply by elmoret

  • elmoret
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Re: Thermister variability in E3D-V6 hot end

Looks like a poor connection to me.

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

4 Reply by cliquot22

  • cliquot22
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Re: Thermister variability in E3D-V6 hot end

I ran the autotune and it seemed to work.  If it develops a problem in the future, I may look at the connector again.

5 Reply by AMWEI Thermistor

  • AMWEI Thermistor
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Re: Thermister variability in E3D-V6 hot end

For Thermistors for temperature sensing, there are tolerance range, such as NTC thermistor R25 tolerance +-1%, +-2%, +-3%, or +-5%, etc. Wider R25 tolerance may lead to higher temperature error. And also temperature error may increases with temperature raises.
Temperature measurement accuracy request in your application range needs to be stipulated to the manufacturer for selecting part.

AMWEI Thermistor Sensor manufacture PTC & NTC thermistors (THERMally sensitive resistors) and thermistor temperature sensors probe, as well as Ceramic Capacitive Pressure Sensors Transducers. Website: http://www.amwei.com, [email protected]

AMWEI Thermistor's Website

6 Reply by cliquot22

  • cliquot22
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Re: Thermister variability in E3D-V6 hot end

The screw holding the thermister in place seemed to be too tight and was causing a short circuit.  After replacing the insulation and adding thermal conductive compound, it all works much better.