Towards a working system
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Inspired by Gus to share my journey. Some quite useful info in that thread. I expect my journey to be a bit more "scrappy", given I'm trying to make this work with some items I have lying around. I also might deviate on the first chemistry I test: we'll see.
For now here's a picture of some of the components I've printed, including two peristaltic pump heads that interface with NEMA-17 stepper motors and that use bearings as the rollers. Links to them here:
- https://www.myminifactory.com/object/3d-print-peristaltic-pump-63137
- https://makerworld.com/en/models/497147-peristaltic-pump-_-nema-17-_-608-bearings#profileId-622582
Small steps, hoping my next post is me showing whether I can get the pumps to work. I'd be curious if anyone has had success with such 3D-printed pumps. I'll try to provide some more feedback in the coming posts too.
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Thanks Kirk!
Here's a brief update. I've decided to see how I can make this with the simplest of tools (i.e., thinking if one didn't have access to CNC or a manual mill).
I've found that using hand files, drill bits, and a coping saw (24 tpi bimetal blade), I can make the current collectors of 1 mm brass with a little elbow grease (WD-40 made the cutting substantially easier). My hacksaw was not a great choice for the thin brass.
In addition, by printing the gasket template for a guide, and then cutting the holes and cavity with some cheap circular punches and an x-acto knife, I got some jenky gaskets.
Not the prettiest, but I'll refine my technique as needed. I'm eager to get to leak testing to see whether my printing settings are OK.
Also, should I have made this a blog post? Happy to delete and move if that's better.
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@sepi Copper should work! My understanding is that the copper is slightly mechanically softer but more conductive. Here, I don't think either of those should matter for performance. Ideally, the current collector by design shouldn't touch the electrolyte so chemical compatibility isn't a concern.
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@sepi I suspect it would be fine. I can't think of any major concerns. Aluminum might(?) be a bit more susceptible to corrosion/passivization at the surface. But I feel like that depends on environmental conditions. Not sure, maybe someone else here has a good reason not to use it.
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Also, here's an update on the 3D-printed pump! Been running it for about an hour, no issues. Unlisted Youtube video . If anyone is curious I can provide more details. Gonna try run it to death, see if the plastic or the tubing fails first.
Oh I should I add I leak tested my cell. I noted a few issues (1) the brass current collectors got bent and didn't seal properly and (2) the ports seem to be leaking. I'll need to reprint those parts with different settings. Hopefully this weekend
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@sepi I suspect it would be fine. I can't think of any major concerns. Aluminum might(?) be a bit more susceptible to corrosion/passivization at the surface. But I feel like that depends on environmental conditions. Not sure, maybe someone else here has a good reason not to use it.
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Since our design prevents direct contact with the current collector, almost any metal should work. you could even use aluminum foil if you really don't want to machine anything (although I wouldn't recommend it! lol). Bear in mind that the graphite foil is not impervious to the electrolyte, it diffuses slowly through it, so if you have highly charged electrolyte some reactivity with the current collector will happen through time (across weeks of cycling).
There is a paper on creating an electrode using graphoil and wax that might be much better (https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/slct.202103996). I will probably get a rosin press to test this and construct some better quality electrodes for our kits.
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@danielfp248 that makes a lot of sense. Being a complete newb, I slowly gather an understanding of the individual components of the cell.
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Thanks Kirk!
Here's a brief update. I've decided to see how I can make this with the simplest of tools (i.e., thinking if one didn't have access to CNC or a manual mill).
I've found that using hand files, drill bits, and a coping saw (24 tpi bimetal blade), I can make the current collectors of 1 mm brass with a little elbow grease (WD-40 made the cutting substantially easier). My hacksaw was not a great choice for the thin brass.
In addition, by printing the gasket template for a guide, and then cutting the holes and cavity with some cheap circular punches and an x-acto knife, I got some jenky gaskets.
Not the prettiest, but I'll refine my technique as needed. I'm eager to get to leak testing to see whether my printing settings are OK.
Also, should I have made this a blog post? Happy to delete and move if that's better.
@quinnale this look great!!
@quinnale said in Towards a working system:
In addition, by printing the gasket template for a guide, and then cutting the holes and cavity with some cheap circular punches and an x-acto knife, I got some jenky gaskets.
I've done similar, it's definitely possible as you've shown!
@quinnale said in Towards a working system:
Also, should I have made this a blog post? Happy to delete and move if that's better.
Oh no worries there, I made that category in part as a container for Daniel's blog - WordPress and our forum software can interact (via ActivityPub), so that we can reference and comment on his (and other people's) longform WordPress posts directly here in the forum, like what's happening here.
@quinnale said in Towards a working system:
Also, here's an update on the 3D-printed pump! Been running it for about an hour, no issues. Unlisted Youtube video . If anyone is curious I can provide more details. Gonna try run it to death, see if the plastic or the tubing fails first.
That's awesome! Having another pump option besides only Kamoer would be great (esp. an open-source one!). It's this pump you've used?
@sepi said in Towards a working system:
eing a complete newb, I slowly gather an understanding of the individual components of the cell.
Glad to hear it, that's one of the whole points of this forum!
