repair broken part with a 3D print

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
Post Reply
User avatar
AngeloGomes
Posts: 32
Joined: Fri Nov 01, 2019 9:02 am
Real name: Angelo Gomes
Location: Brazil

repair broken part with a 3D print

Post by AngeloGomes »

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.


Image
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: repair broken part with a 3D print

Post by Rex Allers »

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
User avatar
AngeloGomes
Posts: 32
Joined: Fri Nov 01, 2019 9:02 am
Real name: Angelo Gomes
Location: Brazil

Re: repair broken part with a 3D print

Post by AngeloGomes »

Rex Allers wrote: Wed Nov 06, 2019 10:23 pm 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
Posts: 28
Joined: Tue Jul 16, 2019 10:16 pm
Real name: Victor Gonzalez

Re: repair broken part with a 3D print

Post by Victor Gonzalez »

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.
User avatar
AngeloGomes
Posts: 32
Joined: Fri Nov 01, 2019 9:02 am
Real name: Angelo Gomes
Location: Brazil

Re: repair broken part with a 3D print

Post by AngeloGomes »

Victor Gonzalez wrote: Thu Nov 07, 2019 12:37 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.
Victor Gonzalez
Posts: 28
Joined: Tue Jul 16, 2019 10:16 pm
Real name: Victor Gonzalez

Re: repair broken part with a 3D print

Post by Victor Gonzalez »

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.
Attachments
IMG-20191108-WA0003.jpg
IMG-20191108-WA0004.jpg
User avatar
AngeloGomes
Posts: 32
Joined: Fri Nov 01, 2019 9:02 am
Real name: Angelo Gomes
Location: Brazil

Re: repair broken part with a 3D print

Post by AngeloGomes »

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.
Post Reply

Return to “Vacuum Technology (& FAQs)”