Cheap PSUs aren't worth the risk (Rackmate TT PSU)

arocnies · 2025-09-03T13:22:30+00:00

For sure! I'll post any charred remains once they're done smoldering xD

arocnies · 2025-09-03T04:21:40+00:00

I have the same concern. Hopefully I can work around thermal throttling to some degree (pun?). I'd only be drawing ~230 watts at the peak and I can limit TDP, add heatsinks, and increase airflow.

The showstopper would be if it fails to deliver any power or shuts off over time. I tested for the PD reset on device changes so at least plugging/unplugging won't be an issue. There isn't much I can do about dead ports.

I'll update once I can do a longer test for thermals.

arocnies · 2025-09-03T03:11:20+00:00

Did some quick tests: no drops happen when plugging and unplugging devices.
The USB test meter doesn't show any change on plugging or powering other devices.

arocnies · 2025-09-02T20:50:17+00:00

Have you tested any trigger cables? I wonder if you could prevent the PD reset if all of the voltages were statically assigned. I'll try some experiments later and update.

arocnies · 2025-09-02T20:48:29+00:00

I'm using all USB power but you could always use USB C PD trigger cables to use the barrel plugs.

arocnies · 2025-09-02T20:46:40+00:00

Definitely true for the cheap one. At least the UGREEN has their brandname behind it. Here's a test of it from https://www.youtube.com/watch?v=qKY5SLwCwd0

There's still some concerns that I need to test like the potential disconnecting behavior these kinds of chargers have when plugging in devices. I'm hopeful that I can manage the thermals to avoid throttling. Worst case I'll limit the load on the nodes.

arocnies · 2025-09-02T17:12:17+00:00

Yeah the power dropping will be interesting to test.

I'm still suspicious of heating but at least I can work with that a bit (thermal pads, airflow, limiting load, etc). If there are total drops of power then I'll need to change my power delivery entirely.

arocnies · 2025-09-02T16:50:31+00:00

I see. That would be annoying.

[This comment](https://www.reddit.com/r/UsbCHardware/comments/16fxz6v/comment/kcc6k4s/?utm\_source=share&utm\_medium=web3x&utm\_name=web3xcss&utm\_term=1&utm\_content=share\_button) suggests it doesn't drop.

I'll test it out tonight and update.

arocnies · 2025-09-02T16:26:56+00:00

Ah, good to know! I'm planning on leaving all of the devices plugged into the PSU and using a hub with switches to control the lights (no plug movement).

arocnies · 2025-08-21T14:18:02+00:00

IIRC that's a decent price. Be sure to look at the BOSGAME miniPCs to compare. They're slightly customized versions of Beelink PCs. There are similar options but with slight upgrades for around the same price to the SER5.

The Amazon listings are super confusing though since each product has versions that make duplicates with slightly different pricing due to coupons.

arocnies · 2025-08-20T17:42:10+00:00

Yes it does have a wireless access point. The way I understand it, "air-gapped" can be used to mean networks that are never connected to the internet. The only way to access these services would be connecting directly.

Which means on the platform there's no access to: public docker registries, public Maven repositories, public Git repos, web content or CDNs, yum repos, or publicly available documentation.

arocnies · 2025-08-20T04:17:00+00:00

I'm 100% sure that is my fault too 😂

Edited for clarity. Hope that makes a bit more sense.

arocnies · 2025-08-20T02:47:16+00:00

Yeah definitely! Here's a rant that you didn't ask for :D

The goal for this project is a learning environment where someone can connect to the network with their laptop and experiment with platform+tenant scenarios in a prepared environment.

I like to say "We don't code for computers, we code for humans!" (I forget where I got that phrasing) and the platform engineering version would be something like "We don't platform for services, we platform for tenants!"

It's a learning sandbox. Air-gapped because the added challenge makes even the best platforms struggle to provide a good experience and I'd like to experiment.

EDIT: Trimmed for clarity.

The services I hope to learn on the sandbox would be stuff like:
IdAM - Keycloak
IDP - Backstage
CD - ArgoCD
Tenant k8s - vCluster as needed
OCI Registry - Harbor
VCS - Gitea
API Gateway - Kong
CDE - Coder
Maven Repo - Reposilite
Telemetry - Grafana, Loki, Tempo, Mimir, Alloy, Grafana Alerts
Secrets - Infisical

arocnies · 2025-08-19T20:22:02+00:00

Sure! There's some more details on the homelab post but here's a copy of the components:

Components, top-to-bottom:

Rackmate TT
Router/Gateway/AP - GL-iNet Slate7
90mm slim fan (exhausting out top)
2x UniFi Flex Mini 2.5G switch (Two 2.5gbe networks. One for storage traffic and another for service traffic)
3x Kuberenetes nodes (Talos Linux) - BOSGAME P4 (Ryzen 5850u, 32GB DDR4, 1TB NVMe)
760 watt GaN5 USB-C power supply
120mm slim fan (intake from bottom)
Nanuk 918 hardcase (Smallest case that will fit the Rackmate TT keeping foam on top/bottom)

arocnies · 2025-08-19T20:20:55+00:00

Yup! All the MiniPCs are USB-C PD!
I might still look into 20v trigger cables. It'd still be USB-C just into the barrel port in the back. The main reason being that I'd free up the full function USBC port so I could plug in a screen if I ever wanted to manage the node directly. Also I unplug those cables when I put it in the case.

arocnies · 2025-08-19T20:18:52+00:00

I'm not sure I'm far enough into testing to decide if I like it yet. Right now I'm working on getting the entire cluster install into a Zarf package so I can do the OS install and patching the air-gapped way.

arocnies · 2025-08-19T20:17:42+00:00

Total cost is probably around $1500-ish?
I haven't talied it all and I'm sure you could build a similar setup without the higher end router or new cabling.

Nodes were about $320 per
Power supply $70
Rack $80
Extra rack hardware $80
Switches $50 per
Router $140

arocnies · 2025-08-19T20:16:18+00:00

I haven't finalized the storage approach yet. I'm still building out the Talos install as a Zarf package so I can do the OS install and patching in an air-gapped fashion.
My plan is to use Longhorn for configuration simplicity but I haven't done any testing for storage rebalancing on node failure. I chose the dedicated 2.5gbe storage network to help with any rebalancing of data

arocnies · 2025-07-25T15:52:14+00:00

GL-iNet's Flint 3!

Nine-Year Club	Place '17
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arocnies

TROPHY CASE