Hi :D
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New member here.
I'm a Scottish engineer based in London.
I'm a member of London Hackspace, and a few of us have been talking about working together assembling a dev-kit. With the tools that we have available, we would be able to work on designs with a larger form-factor...
I came across this project via Mastodon, and just finished watching the FOSDEM 2025 talk.
One of the problems you mentioned during the talk, was the materials used in the components, being reactive with the liquids.
When you mentioned the pump failure due to this, i recalled this instructable for a 3d-printed water pump:
https://www.instructables.com/3D-Printed-Powerful-Water-Pump-That-Is-Portable/
Whether this design of pump has the optimum flows for the battery system is a separate question, but as it's manufacturable from a standard electric motor, and printable components.
As they are printable, they can be made using your choice of printable materials, so that would avoid some of the problems you have already found.
Looking forward to trying these out.
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Hey @BillySmith welcome!
That's great that you and a few fellow hackers are interested in building a dev kit - let us know how we can help! I am still scheming up the large-format cell. I would really like it if we could FDM print it in polypropylene, but not sure if that's feasible yet. I have some initial thoughts and pictures related to the large-format cell here: https://fbrc.nodebb.com/topic/11/designing-the-flow-frames-for-the-large-format-cell
In the dev kit, we were using peristaltic pumps which failed due to incorrect tubing - those pump at about 60 mL/min. In the larger cell, we will have to use centrifugal ones like the ones you linked to, but we can't have a rotating seal like in that link shows - we need pumps driven with a magentic coupling (also called mag drive, hermetic seal, etc). Here is another forum thread on it with an exploded view: https://fbrc.nodebb.com/topic/8/how-should-we-control-the-centrifugal-pumps-triac-thyristor-etc-need-help-from-controls-electrical-people/12?_=1739427920720 . That pump is the smallest mag drive I could find, suitable for "chemicals" (so made from polypropylene or PVDF) - and it's around 6 L/min flow, so two orders of magnitude higher!
They are made from polypropylene, which is ideal for our case. Right now we are trying to figure out how to control/modulate their speed/flow, since they came with cheap AC motors.
Again, warm welcome to the project and please let us know how you get on with the dev kit! We are still finalizing a suitable first chemistry for stable cycling for the kit.
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Reading the posts about the different pump designs, it makes more sense.
More background reading to do.
TY
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K kirk referenced this topic