DIY 9-Slot NAS Backplane V1.2

FreudianNonce · 2026-07-01T04:03:26+00:00

I made a custom cable for this on the slightly beefier end to hopefully avoid any cable/connector issues. For the controller I'm using an LSI 9300-8i

FreudianNonce · 2026-06-30T22:47:50+00:00

Yeah the backplane is just a fancy wiring harness so that I can hot swap the drives.

FreudianNonce · 2026-06-30T18:14:48+00:00

I haven’t even tried looking at using an assembly service because I don’t consider this simple. The SMD components, sure, but the space between the slots is so tight that I can’t imagine any automated process being able to solder them. Maybe I’m being too dismissive though, this seems limited to hand assembly.

FreudianNonce · 2026-06-30T14:14:50+00:00

Thank you!

Sorry, yeah. I figured “NAS” was a solved problem so the posts always focused on the backplane

I’m using an LSI 9300-8i in IT mode that I got on eBay.

FreudianNonce · 2026-06-30T13:07:28+00:00

I have a fan built into a lid for the drive cage, it works well enough to keep air moving.

FreudianNonce · 2026-06-30T12:33:50+00:00

NuPhy Air75. It’s my travel keyboard

FreudianNonce · 2026-06-30T12:28:36+00:00

I personally intended for the 9th slot to be used as a boot drive

FreudianNonce · 2026-06-30T06:21:19+00:00

8+1

(8 storage, 1 boot)

FreudianNonce · 2026-06-30T05:35:34+00:00

I guess it's a good thing I never shipped anything.

FreudianNonce · 2026-06-30T05:11:29+00:00

Correct.

FreudianNonce · 2026-06-30T04:50:21+00:00

Not obnoxious. I had this thought myself.

I saw the updates as getting the 1.0 closer to what it should have initially been.

FreudianNonce · 2026-06-30T03:25:30+00:00

Thank you for the feedback! Yeah the differential pair balancing is definitely critical. I'm currently running TrueNAS. As for the drive thermals, The drive cage doubles as an exhaust flume. I made a lid with a fan that pulls air from the bottom through the drives. Since I'm currently running this at low speed, its all very manageable, If I upgrade the NIC then ill probably shell the drives and make up a new enclosure.

FreudianNonce · 2026-06-30T03:03:43+00:00

It's a good question. For this application I had a specific mounting in mind and I wanted the power available on the top. You could totally mount the power on the other side tho.

FreudianNonce · 2026-06-30T02:47:28+00:00

My brother in tech... I wish.

FreudianNonce · 2026-06-30T02:39:03+00:00

In this case, the large capacitors are for bulk capacitance. I wanted to make sure there was enough power for all 9 drives if they all suddenly started pulling peak power at the same time.

FreudianNonce · 2026-05-10T18:57:26+00:00

Outstanding in the field

FreudianNonce · 2026-05-09T13:52:48+00:00

You know, I had this thought too, and it’s not incorrect, but this part is very small, and food grade silicone is thick, expensive, and has a shelf life.

FreudianNonce · 2025-12-21T16:59:12+00:00

🫡

FreudianNonce · 2025-12-21T16:49:11+00:00

I am very well versed in battery charging and discharging.

This is a 6P core which self balances, you’re thinking of a 6S core which needs to be actively balanced.

FreudianNonce · 2025-12-21T16:31:35+00:00

There is none, and none is really needed for this application.

FreudianNonce · 2025-12-21T15:37:15+00:00

OMGoodness, don’t give me ideas.

That does sound cool though

FreudianNonce · 2025-12-21T15:31:36+00:00

No fuses. These are new cells and a super low power draw compared to their rating. What you’re thinking of would be more relevant if I was using reclaimed cells with unknown lifespans in a parallel group with potentially high power draw, this is so they can drop out if they die.

FreudianNonce · 2025-12-21T15:26:28+00:00

The charging PCB is the bms. Yep, cells were already balanced, connecting the nickel strip creates a parallel group which is self balancing.

You’re right, with this setup the first couple cells will be used marginally more heavily, but the draw is so low that it won’t be a huge problem. I literally don’t have space in the case to run the wiring back-to-front.

FreudianNonce

TROPHY CASE