My build (very slowly progressing)

[sepi]

@kirk duh, now I feel like an idiot about that button. I "fixed" my butten by heating it with a lighter and giving it a light squeeze at the end :D.

[sepi]

@kirk about the jig, yeah I modified the FreeCAD version. It's probably prone to tipping. I'll see that once I get the pumps and hobo modify it and then modify my model and share it.

[czahl]

@sepi Great job, your assembly is really looking quite good. Can't wait to see how it will perform.

[sepi]

@czahl Thanks mate! I'll keep you posted. The pumps and potentiostat are in the mail and on their way to my place

[sepi]

@czahl said in My build (very slowly progressing):

@sepi Your PP parts are looking good. Which filament did you used?

https://www.3djake.com/fiberlogy/r-pp-anthracite?sai=12757
It's pretty soft but that might just be PP. I never used PP before. I just selected the cheapest one on 3dJake.

[danielfp248]

@sepi Nicely done! Also don't forget to wrap your screws in packing tape before you assemble the device for testing, otherwise the screws will short the cell.

[czahl]

@sepi BTW, have you done a blow test with your assembled cell? Should be easier now as you just need to blow into one pipe while closing / opening the other one, right?

[sepi]

I've done it with just one flow frame: That seemed to be good. The problem with your proposal is that (at least that's what I think it is) the photo paper is permeable to air. I might put a piece of tubing on the second flow frame to test the seal on the whole cell. Then again, the only real test is to use some liquid. For that I need to wait for those pumps to arrive, which should be this or next week.

[sepi]

@danielfp248 I actually used Kapton Tape but should probably use PP-tape instead.

[czahl]

@sepi said in My build (very slowly progressing):

I've done it with just one flow frame: That seemed to be good.

This sounds great. I also want to do the same then to eliminate as much of uncertainties as possible from the very beginning. It is always frustrating to identify such bugs after assembling everything together. For sure, the final test is the one with the liquids. Looking forward for your first tests with the pumps installed.

[danielfp248]

@sepi If you have an assembled cell with everything except the pumps you can use a syringe to manually pump some liquid through and see if you have any obvious leaks. This is how I normally test cells before I put activate material inside them or cycle water through them using pumps.

[sepi]

@danielfp248 Good trick, now I only need a syringe.

[sepi]

My Mystat finally arrived, yay! No I need to figure out how to flash that pic (hopefully no programmer neede) and get rid of the remaining 5 PCBs.

[danielfp248]

@sepi You do need a programmer to flash that. We use a PcKit3 programmer.

[sepi]

@danielfp248 noooooooooooo. I'll add: replacing it with an esp32, to the list of projects I will never do.

[czahl]

@sepi Good idea, I was also thinking to use a ESP32 with micropython - makes prototyping much easier and if you like you can easily add a simple web UI.

[sepi]

Yay, I got my MyStat working (a least to some extent). After fiddeling a bit with the yucky Microchip ISP software of which I had to install an outdated version (3.20 afaik) because they removed PicKit3 support, I finally managed to program Kirk's firmware on the device. Getting to run the python host software was fortunately pretty easy.

At first I was a bit stumped by an error message about an out of range current which I tried to calibrate away. It only occurred to me a bit later to connect the main PSU, which corrected the issue

Unfortunately I have some issues with commands that don't go through like the one for saving calibration to the device returning '?' instead of 'OK'.

Any Idea @kirk ?

[kirk]

I am less familiar with the MYSTAT hardware/firmware, that repository is a fork and you can see the original developers efforts much before mine! Just to say I'm not super familiar, @danielfp248 programed mine and sent it to me in the mail

Yes, the main PSU needs to be connected for current measurents to function.

Also a warning, make sure the MYSTAT is completely powered off and unplugged before inserting/removing the measurement cable to the MYSTAT, otherwise there is a risk of damage.

Are you following the calibration procedure from the original paper with a (IIRC) 1k resistor?

[kirk]

Also actually @danielfp248 made all the code improvements to the repository for MYSTAT, he just dislikes Git and so I'm the one who uploads them

[czahl]

@kirk Is there an updated version of the firmware available? The mystat repo includes the changes of the python UI only, but e.g. not the ones for the 4 instead of 3 range switches.