ERE Repair Cafe Mastermind Group

[jacob]

This was a triumph. I now have the right size flange coupling. Thanks amazon for dropping it off w/o ringing the doorbell once again.

So far this has been an exercise in buying correct/compatible parts.
RS550 motor: https://www.ebay.com/itm/155198531351
Motor controller: https://www.amazon.com/dp/B071NQ5G71
Coupling: https://www.amazon.com/dp/B08333PNZQ (3.17mm, not 3mm ARGH)(*)
Power supply: 18V/1A adapter from an LED floor lamp

Next step:
Figure out how to make a propeller.
Acquire 5 gal buckets and pressure fit couplings.

(*) Forensics: I first ordered a 3mm coupling. The reasoning was that while my $2 plastic caliper showed the shaft being 3mm+, 3.17mm sounded like an odd number compared to 3mm. Usually when it coming to pegs and round holes, wood is forgiving but metal is not. So part of the confusion was also an ID vs OD concern. I was worried that 3.17 might be too loose. However, given how 3.17 fits fine, I realized that 3.17 is pretty much the same as 1/8". I briefly considered trying to drill out my 3mm coupling, but I figured the potential for catastrophe would be high using a drill press.

[jacob]

The general ambition, project, and time-allocation level of our MMG is way lower than this (I think?) https://youtu.be/hMAvbu9OzwI?t=1372 but the attitude of learning remains (I hope!). Incidentally, if you're into DIY robots, Fielding's entire channel is great! I goes all the way back from the early start of making his own jigs and powertools, then building garage sized CNC machines, and now making [industrial] robots. A great example of a self-directed learning curve. (Also if you watch the whole youtube link, there are some holistic systems-design insights ala "you can never change just one thing" around the 35m mark which are generalizable.)

Posted for potential inspiration.

Next meeting this Thursday using google meets.

[AxelHeyst]

Oh that is an amazing channel. I don't have any desire to build a robot (ironically, since my dad was an industrial robotics engineer), but I think my ambitions for a Mojave sunken greenhouse with aquaculture and an evap-loss only recirculating water system might come close.

Since it's neither smoke season nor allergy season anymore, motivation for my hepa-filter projects has been flatlined. That said, I've got a couple projects worthy of the group:
.Serenity's power system is having issues - under a moderate load the battery voltage drops rapidly and my inverter does a low-voltage shutdown. I suspect two battery cells are kerput, but I need to verify that my solar charge controller is doing what it's supposed to be doing. Learning opportunity here is to dive into the weeds of MPPT charging algorithms, and how to diagnose if it's an SCC issue or an AGM battery issue.
.The seismic retrofit of my studio. I'm installing some gusset plates between the girders and posts, but I need to learn a bit of seismic engineering principles to decide how to properly brace the structure, including from shear uplift forces. Preliminary digging into how they brace mobile homes reveals that... every earthquake, they update the building codes because a bunch of homes slide off their foundations, crush the utility connections, and start a fire. So I need to come up with something better than code.
.The next phase of my neighbor's PV system upgrade is to design and install a DIY panel ground-mount system that can handle the winds we get around here.

[jacob]

We ran out of repair projects and got busy with other things, so the Repair Cafe has been shut down.

We may restart in the future. Please post below if there's interest.