Strange ABS smell after upgrade to new E3D hot end This weekend I upgraded

Strange ABS smell after upgrade to new E3D hot end

This weekend I upgraded from a QU-BD hot end to an E3D Hot end.

Now, when printing, I notice a very distinct ABS smell - whereas I did not perceive this odor before…

The differences I can think of before and after

0.35 nozzle .4 Nozzle
QU-BD Hot end E3D Hot End
Epcos 100k Thermistor New 100k Thermistor Axial lead for improved sensitivity.

I use the same filament and settings as before (ABS White, 1.75mm Extruder 230c, Bed 115c).

I’m wondering if at the E3D hot end I now have a temperature that is very different to what I had before and perhaps that temperature differential is causing the ABS smell?

I am puzzled by the cause; it’s probably unrelated to the new E3D hot end but I thought it an interesting coincidence in timing.

Any ideas?

Did you switch your firmware to the right thermistor table? It may be significantly hotter than you think it is.

Are you sure it’s an ABS smell? Those cartridge heaters always have a smell the first time you heat them (kinda smells like dust to me). This occurs (and may even be more pronounced) if there is no plastic in it at the time.

Hi Rich, that is a reasonable theory. From my limited experience, the prints do look like they are running hot - the ABS is coming out very shiny.

I previously was using the 100K Epcos Thermistor that came with my Azteeg X3 from Panucatt. While Roy’s instructions said to use TYPE=6, I am using Repetier firmware and I think that was intended for Marlin.

Here is what I had listed in Repetier Firmware.
#define EXT0_TEMPSENSOR_TYPE 1 // 100k thermistor (Epcos B57560G0107F000 - and many other)

Recently, at your recommendation to get better temperature sensing, I purchased the Honeywell_100K_Thermistor from DigiKey,

When I went to set up Repetier firmware, there was no setting for the Honeywell 100K Thermistor, so I used the same setting as before:
#define EXT0_TEMPSENSOR_TYPE 1 // 100k thermistor (Epcos B57560G0107F000 - and many other)

I did run the PID calibration twice after installing the new firmware.

Is this incorrect? Do I need to define this as a custom thermistor type in Repetier Firmware? Is there an equivalent code I should use?

Update: this is the Thermistor I purchased:

Yes, the epcos thermistor table is be pretty inaccurate with a honeywell thermistor. That thermistor is table 7 in Marlin/Sprinter. If repetier doesn’t include it, you could probably port it from there.

Thanks, I will do that this evening. I appreciate your guidance.

Due to the thermistor’s beta values, your temperature could be off by as much as 40°C - i think @Sanjay_Mortimer (and generally every hotend maker) should post a precise thermistor table for the bread-and-butter 4k7/0R setup and a short note on how to use it.

@Thomas In fairness to Sanjay, I am not using the thermistor that came with the E3D - I am using an axial lead unit for (hopefully) better temperature measurement within the heater core. That said, I agree, it would be helpful to have the most common thermistors provided for within the firmware and, for thermistors shipped with hot ends it would be great to include specs and setup details. I’m thankful for this group on Google+ and RepRap from which we can share and learn. I’ll try to learn what is involved in getting a new thermistor defined in Repetier Firmware this evening.

Agreed - going to put the specs/part number in the build manual ASAP as well as recommendations for firmware preset selections.

Update: I was able to find the steps to create a user defined thermistor table in Repetier. I found the information in the Repetier forum (RepRap).