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These aluminum extrusions are called T-Slot, or as McMaster-Carr calls it, "T-Slotted Framing". Very common in industry; we have it everywhere on the Boeing factory floors. Not cheap, but very durable and reusable. Highly recommended.
Check it out starting on page 2240 of your McMaster-Carr 132 catalog. They have all kinds of things you can mount up like monitor arms. It's an erector set toy for engineers. ;)
I have a couple of these, they are made of a light gauge sheet metal; the inner dimension is ~9.75", wider than the 10" standard hole spacing; and I don't think they would be very structurally sound if you were to remove the back panel. Doesn't seem very well suited to me.
Why use the original power bricks, with the space claim and awful routing, instead of just going to a single dc/dc... either directly if no individual power control is needed, or to a relay block or switch block if automated / manual individual control is needed?
I remember seeing this great video where they built their own power supply for their mini rack. Quite a project but ended up being a pretty cool solution to the problem.
I bought an 800w GaN USB-C charger from AliExpress (https://www.aliexpress.com/item/1005009093660588.html) and a handful of USB-C to barrel jack adapters. They're powering 2 EliteDesk G2s (35W) and 2 EliteDesk G3s (65W); not had any trouble so far though the GaN charger does run a bit hot (which I resolved by putting a fan under the charger).
Admittedly I can't be sure of the long-term reliability of the GaN charger, but its been running problem-free for over a year now.
One option is to stick a mini-UPS in-between the wall the devices. Such a thing is internally a handful of lithium cells and some DC outputs.
For powering a handful of things that consume less than 100W they are quite useful because they typically provide 2 or 3 DC outputs, and replace between 2 and 4 power bricks.
They also provide an hour or two of backup, quite useful in my country where the power sometimes goes out for a bit.
The downside is that I cant find decent ones in my country, and so I end up replacing mine every 2-3 years.
This looks good: I've got three HP NUCs like in TFA + three Pi on my desk (got more than that altogether) and it's indeed a cable mess.
> Aluminium extrusions are bars with a groove on all four sides. These bars have a standard format and you can slide all kinds of equipment in there and lock it in place with set screws. It seems to be used a lot for home made 3D printers, CNC machines and whatnot.
They're also called "T-slot" and 80/20 (from the brand).
The appeal of T-slot extrusion here is really a manufacturing economics thing - the dies already exist, so you're borrowing someone else's tooling cost instead of paying for your own. Flat sheet stock is cheaper per gram, but you eat the fabrication cost yourself for anything custom.
Built something fairly similar about 15 years ago. The cheapest way by far to do it is get everything you need off Aliexpress except the alu sheets which you can typically get as offcuts from local manufacturers, I was lucky enough to pick up some odd shapes that had been used for signage for next to nothing that I could cut to the right size. Since you need to buy bags of 50 or more of the M5 fixings, you an bundle them up and recover some or all of the cost by selling them locally once you've used the few you need.
It would be cool to design custom aluminum brackets for the fans. However I found that although ordering 3D prints is very cheap, using (for example) PCBWay for CNCing something out of aluminum is very expensive.
Try to avoid milling unless you absolutely need it. Better to go 2D with some tolerance and print small adapters, or use standard T-slot hardware, to connect it. It's often educational to browser McMaster just to get a feel for what standard parts even exist.
For a bracket I would look at a laser or waterjet service. Sendcutsend is one of the more well known web shops and the pricing is OK for the convenience. Also look out for local places that are linked to education. Some libraries even have laser cutters. One shop near us will do simple jobs for machine time + material cost, like you give them a DXF and they'll cut acrylic for a good price. Other option for metalwork is to join a makerspace. The dues are often very reasonable vs trying to get a lathe into your house.
I got the TecMojo 10" 6U rack[1] from Amazon for less than $100. It's great, and even came with 2 HTML USB adapter boards (I think for some variety of R-PIs?)
Getting something with actual, standard rack-mounting points is worth it because you can use the huge variety of 3D printed hardware to match it very easily.
I agree with the other commentators that power bricks are a problem though. My setup is fanless and silent which is an extra challenge.
I do some FOSS work with bootloaders and would love a cheap setup where I could leave boards running and have remote access to their UART/SPI/power.
Occasionally I need to be able to get physical access to it too.
I use esp32 for the remote UART/SPI, but don't really have a good setup for keeping a few projects tidy, and with the ability to move it from its remote location (a bookshelf) to my desk for physical access.
Does anyone know of any cheap and dense way to store these projects/boards?
They are usually ludicrously expensive. But since Chinese manufacturers started using them for various small machine (3d printer, engraver...) frames, there's a now finally a cheaper supply.
O call it shelf for stupid HP shitboxes, with no redundancy, high consumption and low performance.
I bet these are old corporate scrap metal with something horrid like i3-9100T.
Nothing a wall mounted Chinese NUC with 12-13th gen i7, 2x32GB DDR4, 2x PCI-e 4.0 NVMe, 2x LAN can't do much better for price of that NOT-rack and fraction of electricity.
I think the issue is that these arent close to rack specification. So its a rack in that its a set of shelves, but its not a Rack as the technology industry would define it.
Rack rule is 19 inches, that's the whole spec really. We used to build custom shelving for our server closet before we could afford real rack gear, called it a rack too. Nobody's shipping product in it, so who cares what you call it.
I considered going the 10 inch route too but ultimately decided on a small 19 mainly because I also wanted to fit a ATX build in there and most gear is 19 standardised
No isolation transformer or anything on the PSU input then? Curious if that's ever bitten anyone with a metal rack sitting on a wood desk near other grounded gear, or if modern PSUs just don't leak enough to matter.
I'm no expert but to my knowledge metal cases always need to be grounded. Which is what I did with my 10" rack. I just bought a socket with a ground connector from an online store, although I'd be curious which exact cable is best practice. I don't have many things connected there anyway and the power supplies are outside of the rack.
FWIW the topic is quite a rabbit hole and for non-mobile metal cases (e.g. screwed on the wall) technically even an electrician seems to be needed.
Did something similar with 2020 extrusion for a NUC cluster. Biggest lesson: buy drop-in T-nuts, not slide-in ones, so you can add brackets after the frame's built without disassembling anything. Saved me hours when I kept changing the fan/PSU layout mid-build.
Check it out starting on page 2240 of your McMaster-Carr 132 catalog. They have all kinds of things you can mount up like monitor arms. It's an erector set toy for engineers. ;)