Posts made by darrklogik

It looks like the No# 60, #11 or #13 in the Marlin firmware is the correct one to use for the HT-NTC100K thermistor. Im not sure what it is in the Repetier firmware though... As long as the Beta is 3950 it should be good to go...

Temperature/Resistance tables for the HT-NTC100K B3950 thermistor straight from china land.

The guys on the keenvo store via the Aliexpress phone APP gave me this pdf datasheet. Hope it helps you guys set this up for the Duet3D board!

After looking at the latest Marlin Firmware, I noticed the thermistor for the CR-10 5S 12VDC hotbed is set to "no# 5":

5 : 100K thermistor - ATC Semitec 104GT-2 (Used in ParCan & J-Head) (4.7k pullup)

So you would define your extruder thermistor like so:
#define TEMP_SENSOR_0 5

Maybe it matches the resistance/temeprature curve at lower temperatures? Looking at the "ATC Semitec 104GT-2" thermistor table, it does look different. See attached PDF.

At 0 deg celcius, they differ by 26 ohm (out by ~1.5 deg c)
At 10 deg celcius, they differ by 8.6 ohm
At 20 deg celcius, they differ by 1 ohm.
At 30 deg celcius, they differ by 2.7 ohm
At 40 deg celcius, they differ by 2.5 ohm
At 50 deg celcius, they differ by 2.4 ohm (out by 2 deg c)
At 60 deg celicus, they differ by 2.5 ohm
At 70 deg celcius, they differ by 2.1 ohm (out by 4 deg c)
At 80 deg celcius, they differ by 1.7 ohm (out by 5 deg c)
At 100 deg c, they differ by 1.2 ohms (out by 8 deg c)
At 150 deg c, they differ by 0.41 ohms (out by 14 deg c)
At 200 deg celcius, they differ by 0.5820 ohm - 0.4393 ohm = 0.1427 ohm (out by 18 deg)
At 240 deg celcisu, they differ by 0.2737 ohm - 0.2065 ohm = 0.0672 ohm (out by 15 deg)

Looking at the data extract above, its reasonably accurate at lower temperatures. I would say 0 deg c up to 75 deg c. However, its get more innacurate above 100 deg c., and gets steadily worse. It's definately unusable above 200 deg c. So you could use marlin thermister Type No# 5, for the HT-NTC100K B3950 thermistor, for temperatures below 100 deg c for the hotbed for example.

Links to datasheet:
[https://e3d-online.com/100k-ohm-ntc-thermistor-semitec](link url)
[http://www.atcsemitec.co.uk/gt-2-glass-thermistors.html](link url)
[https://www.keenovo.com/NTC-Thermistor-R-T-Table.pdf](link url)

0_1541669367568_GT-2-glass-thermistors.pdf

0_1541668949826_NTC-Thermistor-R-T-Table.pdf

Hi There. I recently purchased a Keenvo 240 VAC silicon bed for my CR-10 5S from aliexpress. They supplied the HT-NTC100K B3950 thermistors with the bed, and a data sheet for this representing Temperature @ given resistance value. Please see attached pdf. I hope this helps you guys. Note, I replaced my standard 12VDC bed with this new keenvo bed, and simply cut and soldered the existing thermistor sensor wire leads coming from the CR-10 computer box. I threw the old metallic hotbed with its doublesided tape stuck-on thermistor out. I figured I didn't need it anymore. After firing it all up, it worked magically. I didn't configure any settings or reflash any firmware. I matched the temperature display with a laser IR gun, and they matched. I guess I got lucky. Octoprint also reported the same temperature as the IR gun. There was a few degrees difference, but once it all stabilized, the temperatures matched.

0_1541668153724_NTC-Thermistor-R-T-Table.pdf