26 Reply by cephdon (edited by cephdon 2012-11-26 03:19:38)

  • cephdon
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Re: Nozzle clogging

hmm. Ok. I will get one of those as well then.

EDIT: Took me several hours of work to clear my clog the other day (from black filament).. I used the blue filament sample that came with my printer and set it to a speed of 30 and extruded 1mm at a time at a temperature of 200.  The black filament started to come out for a while and then it would jam.  So I let it cool down and then heated it back up and started extruding again.

I did that until the filament was a pure blue color. Took many cycles, but it eventually cleared all black filament from the extruder (at least it seems so).  Once clear, I was able to print successfully again (using the blue sample).

I don't know if this process will work for everyone.

27 Reply by danny

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Re: Nozzle clogging

IanJohnson wrote:

IR thermometers aren't very good at reading nozzle temperatures.  A K type thermocouple that you can plug into a multimeter will give a truer reading- http://solidoodletips.wordpress.com/201 … mperature/

when you use a thermo couple what temps are you getting?

I've just rebuilt my hot end, and decided that I'd measure the temperature. the machine reports hot end at 190, thermo couple suggests closer to 160. I also found that the extruder was skipping and binding.

turning the temperature up seemed to stop the skipping and binding, now I'm printing with the machine thinking it's 210, but there are posts on here saying don't do that because the temp will actually be closer to 240 than 210 and the plastic will burn and clog!

28 Reply by cephdon

  • cephdon
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Re: Nozzle clogging

I got my IR Thermometer today and decided to test it on the extruder nozzle.  I consistently read about 20C higher than the stated temp on Repetier during both heating and cooling.  At 160C requested temp, I am reading ~180C (from 179 to 181 fluctuating).
As the head cools down, I was reading about 20C higher than the reported temp at nearly every point.  So, when I was printing at 200C I was actually heating my filament to about 220C.

When I get the thermocouple I will compare the two methods to see how reliable they are and how much they differ to the reading on repetier.