After a multi-months of little to no time to work on my HercuLien,

After a multi-months of little to no time to work on my HercuLien, I am back in the workshop. Of course, I have a couple of questions:

  1. If you ordered the Ali Rubber 120v heat bed, does anyone know the thermistor type they use, so I can set it up properly in my Smoothie Board config?
  2. Same question for my E3D Volcano, what setting do I use; I did not see the model for the one they sent, I looked all around e3d site, but maybe I missed it.

The rubber heater should be NTC100 about 100k ohm.

  1. The beta value for Alirubber seems to be 3950 (see here ) or check out Erik’s thermistortables.h
  2. The doc at refers to using ‘Semitec’

Doc at Smoothieware:

So in your config you would have
temperature_control.hotend.thermistor Semitec
temperature_control.bed.beta 3950

I’m sure someone here has found more accurate ways (@Eclsnowman maybe), but it works fine for me :wink:

@Oliver_Seiler yes, I confirmed on the alirubber bed via a thermocouple the beta value of 3950 is accurate within 1deg C. Good enough for me.

Awesome, thanks for the quick information on both, and the links, I missed that on the E3D wiki!

@Bruce_Lunde , I used the data sheet for the thermistor and fit it to the Steinhart-Hart equation. This should give you the most accurate values over the entire operating range:

But because it’s only the bed, stability is more important than truly accurate temps

It’s #11 in Marlin, I believe.

For the bed thermistor from Alirubber, I found I needed to add a configuration of R0 to be a bit less than 3000. R0 is the resistance of the thermistor at 25C. You can measure that with a multimeter if you want.

Thanks all, I have updated my setting, now I just have to wait for an extruder gear and some screws to finish up (how is it that parts just disappear from the workbench,) . Lucky for me Filastruder and Trimcraft have already packaged for shipment, so with luck (and USPS) , I may be finalizing the build this weekend.

I know many orders from alirubber and Thats probably good
I ordered My from robotdig, i thought that might be interesting for you to look at as well
This is the one i ordered

Silicone Rubber Heater Pad

300*300mm, 12V or 24V 300W