repair broken part with a 3D print

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AngeloGomes
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repair broken part with a 3D print

Post by AngeloGomes » Tue Nov 05, 2019 3:50 pm

I have a WRG from Edwards with a broken plastic case (see photo)

I was wondering to use a 3D print part to fit the broken case and use glue to join them.

Any tips/idea about how to obtain the missing part ?

Regards.


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Rex Allers
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Re: repair broken part with a 3D print

Post by Rex Allers » Thu Nov 07, 2019 3:23 am

Not an answer to your question, but... Do you know if it is working? It doesn't look like that broken case would affect operation. I'd want to try it first before going to the trouble to fix or replace the case.
Rex Allers

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AngeloGomes
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Re: repair broken part with a 3D print

Post by AngeloGomes » Thu Nov 07, 2019 12:26 pm

Rex Allers wrote:
Thu Nov 07, 2019 3:23 am
Not an answer to your question, but... Do you know if it is working? It doesn't look like that broken case would affect operation. I'd want to try it first before going to the trouble to fix or replace the case.
I connected to an AGC, as this below:

Image

And it is not recognized anymore, the displays shows ??? ID. However, if I set the AGC to to show the voltage of the sensor, it gives around 10V which is compatible for room temperature (checking the calibration curve). I measured the resistance between pin 4 and 5 and it is 75 kOhm, which is correct for this gauge (75 kOhm is the resistance used by Edwards electronics to identify the gauge type).

So, at least I can read the voltage from the sensor and ignore the AGC.

Victor Gonzalez
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Re: repair broken part with a 3D print

Post by Victor Gonzalez » Thu Nov 07, 2019 5:37 pm

I have the same AGC, if it shows ??? It's lacking a software upgrade.

My new edwars pirani sensor shows ??? so I bypassed the resistor cable to the same value as the old one, it thinka the old one is connected and show the pressure for the voltage corresponding to the old one.

Since the voltage x pressure curve is not the same, it's not ideal to do this, but it gives a good idea of the pressure. Of course you can use the voltage to calculate the correct pressure.

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AngeloGomes
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Re: repair broken part with a 3D print

Post by AngeloGomes » Fri Nov 08, 2019 12:55 pm

Victor Gonzalez wrote:
Thu Nov 07, 2019 5:37 pm
I have the same AGC, if it shows ??? It's lacking a software upgrade.

My new edwars pirani sensor shows ??? so I bypassed the resistor cable to the same value as the old one, it thinka the old one is connected and show the pressure for the voltage corresponding to the old one.

Since the voltage x pressure curve is not the same, it's not ideal to do this, but it gives a good idea of the pressure. Of course you can use the voltage to calculate the correct pressure.

Got it.

I will check with Edwards if I can upgrade the firmware. Meantime how did you bypass ? Indeed, it is a good idea for a workaround to deal with this issue.

I think the AGC should read a drop voltage across the 75kOhm resistor.

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Re: repair broken part with a 3D print

Post by Victor Gonzalez » Fri Nov 08, 2019 3:35 pm

My sensor is a new model (APG100-XL), and my AGC doesn't recognize it but it is a simple pirani, so I changed the resistor value to the old pirani (APG-M), the pressure x voltage curve are different.
As your gauge is 2 sensors combined, you will need to search for the corresponding older model resistor value, as there's 2 pressure x voltage curves for this gauge.

Let me know if Edwards can upgrade the AGC!!


I made this change using a 100kohm trimpot, that way I can choose what type of sensor I want (by varying the resistor value), to do this I just cut the wire #4 soldered it to the middle leg and one of the other leg was soldered to the wire#5 (ground).

If you have original edwards RJ45 cables, buy a ethernet cable to do the bypass, those flat silver wires from edwards are too expensive.
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AngeloGomes
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Re: repair broken part with a 3D print

Post by AngeloGomes » Fri Nov 08, 2019 9:44 pm

Just found the problem is the AGC.

I plugged the sensor in a Edwards ADC and it was recognized.

I am going to dive in the AGC board to check.

About the upgrade: The AGC can identify the WRG gauge. It is not a firmware issue in my case.

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