Raise3D Heated Bed thermistor and Duet2Wifi

[Thomas_Stagsforge]

Hi, I recently bought a Raise3D N2 and decided to install a Duet2Wifi.
I have a question about the heated bed thermistor on Raise3D.
Here is a diagram I did by measuring the resistor installed on the bed.

The bed provide a 3 wires connection : Signal, +5V, GND.
On Duet Wifi, only 2 wires are necessary.

Can I plug the Signal and GND wires of Raise3D Heated Bed, directly on The Duet Wifi ? Are am I missing something ?

Thanks for your help.

Thomas

[Phaedrux]

I'm not familiar with the Raise3d bed design. Can you post a photo?

[Veti]

@Thomas_Stagsforge said in Raise3D Heated Bed thermistor and Duet2Wifi:

Raise3D

https://www.raise3d.com/spare-parts/?series=n-series
from this i would guess its a thermocouple and not a thermistor.

[Thomas_Stagsforge]

@Veti
Hi, I don't see any thermocouple. When I bought the machine, there was some missing part...maybe they remove it before but not sure

[Thomas_Stagsforge]

@Phaedrux
Hi,
Here some pictures :

[Veti]

according to this

https://github.com/Raise3D/Marlin-Raise3D-N-Series/blob/master/Marlin/Configuration.h

the Hotend is a thermocouple

the Bed is a
// 8 is 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup)

[Thomas_Stagsforge]

@Veti
Good, thanks for the information, good idea to check on Marlin. So we can see the sensor on the picture n°2.
I just measure 10kOhm. Don't why I got a 100kOhm when I first checked...But according to the spec i should read 100 000ohm... I'm gonna do futher research. Thanks for your help.

[Veti]

@Thomas_Stagsforge said in Raise3D Heated Bed thermistor and Duet2Wifi:

Don't why I got a 100kOhm when I first checked

because thats the resistance at room temperature of the
SMD Vishay NTCS0603E3104FXT
https://www.vishay.com/docs/29056/ntcs0603e3t.pdf

...But according to the spec i should read 100 000ohm

100000ohm = 100kOhm

[Thomas_Stagsforge]

@Veti
Thanks, Yeah you right but now when I measure it, I got 10kohm... Anyway, I'm gonna plug it back and check on WebControle the value.

Are we agree that this type of thermistor is compatible with Duet2Wifi ?

[Veti]

@Thomas_Stagsforge

the thermistor on its own would be supported.

i am not sure about the wiring and why they included a 5v line.

[Phaedrux]

Doing another search on the Raise3d forums found someone doing a conversion of the N2 to Duet wifi and they say the thermocouple isn't compatible and they attach a new thermistor. But they don't say why or what about it isn't compatible. Using a thermocouple would require a thermocouple daughterboard, so maybe that's what they mean. The 5V line is also confusing. So to even try it you'd need to buy that daughterboard, which will be more expensive than just getting a standard NTC100K 3950 thermistor or PT1000 sensor that doesn't need any additional board.

[curlypaul]

Sorry to hijack, but if you've gone that far, how about re-doing the bed completely ?

After struggling with our N2 Printers, I changed the bed at the same time (as fitting a duet wifi and piezo for z probing) to a machined C250 bed into which i put standard glass into, and heated with a mains powered pad

The stock bed is woeful at best anyway

Has transformed it into a pretty good printer now

[Thomas_Stagsforge]

@curlypaul

Hi,

Thanks for sharing.
I currently trying to keep a maximum of part, but it doesn't mean that I wont change it later.

[Thomas_Stagsforge]

@Veti

Hi,

See this link, I suppose this is why there is +5V.

link text

I ran some test. So I plug the sensor to the duet with only 2 wires. There are connected to Signal and Gnd on the heated bed. The DuetControl app give me 25°C room temperature, not bad. I warmed up the thermistor with a blowdryer, temperature ingrease to 40°C. I currently doing a test with melting ice in a bag to get close to 0°C.

[Veti]

@curlypaul said in Raise3D Heated Bed thermistor and Duet2Wifi:

After struggling with our N2 Printers, I changed the bed at the same time (as fitting a duet wifi and piezo for z probing) to a machined C250 bed into which i put standard glass into, and heated with a mains powered pad

that is really nice!

[Thomas_Stagsforge]

Hi, just a quick update. I did a test with water and ice, the temperature drop at 14°C.

Anyway, I think with the actual smd thermistor it will work.
When my duet2wifi wiring will be finished I'll be able to test it in real conditions.

I made a change on configuration file buy editing the B value to match the datasheet specification (4100).

Thanks everyone for your help.

[curlypaul]

@Veti thank you