Techzone Monotronics, replacing ethernet cable to tip

Hello everyone,

I'm getting fluctuating temperature readings in RepSnapper from the thermocouple on our Techzone Mendel. The temperature fluctuates within about 8 degrees Celsius when heat is off, and about 90 degrees when I switch the heat on in RepSnapper.

I have no clear sense of what the problem is right now, maybe interference along the Cat5 cable that is used to send power to the nichrome wire and read the thermocouple?

Does anyone know which wires are paired together in the cable? I went to this page to find the schematics, but they are missing.

I also noticed that if I unplug the 12v power supply for the machine, but leave the USB connected so RepSnapper can still read the temp, the fluctuations stop.

But why all of a sudden? It happened a few times before, but too briefly to track down. We would just unplug the connector at the A/D converter and it would stop.

Any ideas?

Yvan

Edited 1 time(s). Last edit at 05/19/2012 11:57PM by Yvan.

You could maybe find which cables are used together by having a look at the circuit boards drawings (PDF files for PCB layout).

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

These fluctuations in temp readings are intermittent, and are now gone! So after loosing a day, I've been printing again!

I've looked at the circuit board layouts you mention, but it seems tricky. One bad guess and I could fry the Monotronics...?

If the problem comes back, I just might try this instead. Seems I could cut the A/D converter tip control module right out and move away from RepSnapper at the same time. But... that is a bigger step, and it would be nice to just re-wire the Cat5 instead.

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Yvan

Singularity Machine

The other - painful - alternative is to check for end to end connections between all wires on your working cable.
That's only 8² possibilities to test, you might want using a spreadsheet to track your results

I believe I remember - don't trust me on that, I'm not responsible if you fry your board - reading somewhere that what is used is actually a regular straight Ethernet cable and that all the joining is done on the boards.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

"only 8²" !!!

Yes, the ethernet cable is standard, so all the joining would be done on the boards. I would like to group the wires that are sending 12v to the nichrome (5 or 6 maybe?) and then separate the two or three others used for the thermocouple. That might help with the noise/interference.

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Yvan

Singularity Machine