Ender 3 Pro max heater size?

I’m attempting to upgrade my 3 year old Ender 3 Pro with an E3D-V6 hot end.
The problem I’m running into is that the heater from the original Swiss Micro hot end can’t seem to handle the much larger heat block on the E3D. Can’t get the temp past 120C or so. Tuning the PID is not the answer, BTW. I tried that. :slightly_smiling_face:
I believe the original heater is 40W, and I’d like to put a 50W in.
What I can’t figure out, or find references to, is whether the V4.2 main board I have (came with the printer, not upgraded) can handle a 50W heater or not?
Could anyone provide any insight?

HI Andy

short answer, Yes it can handle a 50. Longer answer, there is something else wrong here. The wattage on the heater cartridge will affect the speed at which it reaches max temp but will not prevent it from going over a low temp as such you are seeing there. Although I know your printer is 24 Volt what I would “normally” excpect from this situation is that you are using a 24 Volt heater in a 12 Volt printer.

But for this case I know its a 24 Volt printer from the factory and I am assuming you have not changed that. So there has to be another reason for this.

Can you check the resistance on the heater cartridge and again check the thermistor? Just am curious if they are within band or not. I am trying to keep the explanation as simple as possible on here but I would also check the voltage output at the board and verify you are seeing 24 Volt there. I am suspecting that for whatever reason its not.

In my head its the only reason I can see the temp staying so low even if you are requesting heat.

1 Like

I will check resistances and voltages, but, something I didn’t mention is that I deinstalled the E3D, and simply put the heater and thermistor back in the Swiss Micro, where everything works normally.
I also used the IR thermometer, which agrees with the thermistor.
It didn’t actually stop at 115 or so. What happens in the E3D is that the temp climbs normally to about 100C, then slows down till it’s creeping up at 112, and finally, around 122 or so, the firmware declares a heater error because it’s going too slow.
Same two parts back in the Swiss Micro? Heats up perfectly normally. Weird.

that is bizzare, really should not be a differance like that between setups.should remain pretty consistante between both. Is there any thermal paste or anyting like that in the heater cartridge mount?

Just looking for a logical reason the temp would not reach proper temp. If you have the IR thermal is there any heat creeping up into the cooling tower?

Thanks for the brain power you’ve expended on this :slight_smile:

I wasn’t able to get a shot of the heatsink with the IR because the shroud covers it too much. However, my totally accurate finger touching it did not result in my saying “Ow!” at any time.

The pocket for the heater cartridge in the E3D is clean, bare, aluminum.

I haven’t pulled the cover off the main board to measure the resistances, but I did measure (using my Fluke 73 DMM) my spare set (Branded Micro Swiss) that act exactly the same way when installed:
Heater Cartridge: 16.2 Ohms - calculated 36W
Sensor: 110.5K

I’ve kinda decided to abandon this for the present, since I need the printer running. So, I’m putting the Micro Swiss back in for now, and will revisit this a little down the road, when I have more time.

However, I did figure that I could easily show you what’s going on, I created two videos (linked below) that show what I’m talking about.

Notes on the tests:

  1. The same heater cartridge, sensor, and heatsink fan were used in both hot ends.
  2. The watt meter is inline between the power supply and the main board, so it shows total power consumed, not just the heater cartridge.

Let me know if anything changes in your mind when you see what’s happening.



Micro Swiss preheat to 200C
E3D-V6 preheat

very interesting, now one think I noticed off the top of my head, you measured your thirmostor, it should read 100K ohm. yours is little over 10% diviation @110.5k

That should throw off the temp tables but curious it only affects in on one hot end.

1 Like

I wouldn’t place too much significance on the thermistor resistance being 110.5k. For a typical 100k B3950 thermistor, that’s what you get when the ambient temperature is around 22C-23C (assuming the nominal temperature is 25C).

@Andy.wpg what is the temperature of the room where you measured the thermistor’s resistance?

1 Like

It’s a little cooler in the basement, where my workshop is. Probably 19-20C.

Just out of curiosity, do you have a thermometer and see what the actual temperature is?

actually a very good point Myke, I completely missed that one…

1 Like