bad nozzle temperature

hi ,guys
my machine is ormerod1 form RS-China, use RepRapFirmware0.78c, just upgrade the bed to ormerod2.


When I turn on the machine using USB, always returns “Temperature measurement fault on heater 0”,nozzle temperature is detected as -11 degrees.

When I was heated thermistor by an external heater (hand, iron).Then start the machine using USB, the machine does not return temperature error.

At first, i suspect that the ambient temperature is low due. I do not care.

Now use the PLA print, there are a lot of bubbles, the wire is not smooth.(Like bread honeycomb)

Now I can not judge that the thermistor is damaged, or poor PLA.





I have some thermistor, MF58 100K B: 3950 5%, can replace it?
Or other solutions?

This is a common problem on the Ormerod and has been covered many times on this forum. Solutions include:

1. Ask RRP to replace your Duet board.

2. Replace the 1K thermistor series resistors by 4K7 resistors, as is already done on later production Duet boards. But this may void your warranty.

3. Change to my fork of the firmware, then use the M305 H parameter to correct for the ADC offset. On some boards, this is not sufficient.

4. Connect a high value resistor in parallel with the hot end thermistor. Adjust the value to get about the right reading at room temperature. 330K is a good value to start with.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you, DC42, because of this problem has not been buying your Hot end board.

I understand NO.4.

I have soldered socket DuPont on the board, So, does not warranty

The 2nd, I do not know where 1K thermistor series resistors? A picture guide is the best

Quote
xiaoyao9184
The 2nd, I do not know where 1K thermistor series resistors? A picture guide is the best

The hot end thermistor series resistor is R19 on the Duet, close to the Erase button. The bed series resistor is R21. They are 1% 0603 size resistors.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Great,DC42,Thanks again.

Now i understand why the Ormerod documentation said that “sticker on the Ethernet socket on the Duet board. If there is, and it says ’4.7k’"https://reprappro.com/documentation/ormerod/commissioning/

It appears i will replace the two chip resistors.This job is not easy for me.

I advise against trying to change the resistors yourself if you have not done any SMD soldering and desoldering before. Try my firmware fork and see if the M305 command solves the problem - it's much easier. If that fails, ask RRP for a replacement Duet, or add a resistor in parallel with the thermistor.

If you do change the resistors, you don't need to change R21 unless you particularly want to.

Edited 3 time(s). Last edit at 12/23/2014 02:23AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].