Your own ITX NAS from the 3D printer – Part 1: Introduction, hardware and assembly

Memory / hard disks

Now we come to the most important component of a NAS – the hard disks. I would go for at least 4TB disks, smaller capacities are simply not worth it. How much storage space you need should be considered beforehand. Considering the fact that we can install a maximum of 4 drives, we end up with 8TB of usable storage with 4x 4TB and RAID10, and 12TB of usable storage with RAID5. A full configuration of 4x 8TB and RAID10 results in 16TB and a RAID5 results in 24TB effective capacity. If you want to try something around, quick results for the different RAID modes are provided by the following website.

=> RAID Calculator

A full backup and later incremental backups can take up quite a bit of space, so I would rather think a bit bigger- Alternatively, you can start small with 2x 4TB and a RAID1, and then expand later.

So the capacity is clarified, but which model should it be exactly? Opinions often differ as to whether it should be Western Digital, Toshiba, HGST or Seagate. However, it is especially important that the HDD uses the CMR (Conventional Magnetic Recording) method and not SMR (Shingled Magnetic Recording)! Preferably, the selected hard drive should of course also be intended for use in a NAS, which is the case for the Western Digital WD Red Plus and Seagate IronWolf in the most popular offers. And I also use two of the latter here, each with 4TB.

 

At this point, I can only refer to the Backblaze Hard Drive Stats, if you want to have a look at realistic failure rates of the different models before buying. However, smaller capacities tend not to be found there. 

Power supply unit

To operate the system, of course, it also needs power. The case here uses a flex-ATX form factor power supply to keep everything as compact as possible. Suitable models are available quite cheaply and also from well-known manufacturers.

At this point, one of two paths must be chosen:

• Option A: “Hotplug” setup with removable hard disks, slightly more complex
• Option B: Not easily removable hard drives, fewer cables

If you choose option A with the “classic” feature of a NAS, i.e. simply removable hard drives, you will need various adapters in addition to the power supply. I recommend the following power supply and use it myself:

However, it should be noted here that Flex-ATX power supplies usually do not have 4 Molex connectors, but only two. To solve this problem, we simply use two adapters. The HDDs in their sleds are pushed into a combined cable for data and power at the back of the cradle.

• 4x SATA / Power Combo Cable — AliExpress Shop-Link
• 2x Molex to SATA Adapter — AliExpress Shop-Link

The combo cables are then fixed with the printed parts “drivecage_connector_combined”.

If you choose option B, the hard disks are connected directly to the mainboard and power supply. All you need then are SATA data cables and a Flex-ATX power supply with four SATA power connectors.

• 4x SATA 3.0 Cable — AliExpress Shop Link
• Flex-ATX PSU 4x SATA Power — Geizhals.eu comparison

The hard drives must then be installed and connected before the back and mainboard sides of the case are screwed together.

 

Miscellaneous

And now for all the small parts that are needed:

• 50x screws, M3 x 14mm — AliExpress Shop Link
• 2x screws, M4 x 40mm or PTFE tube for door hinge
• Powerbutton, 16mm Black/Silver, Power on (60cm) — AliExpress Shop Link
• Optional: 4x rubber pads — AliExpress Shop Link
• Optional: 2x steel bars, 2mm x 100mm — AliExpress Shop Link
• Optional: 12x magnets, 5mm x 3mm — AliExpress Shop Link

Among the optional parts:

The rubber pads on the bottom decouple the case so that no vibrations are transmitted.
The steel bars can be used if “side_left_combined” cannot be printed in one piece to increase stability. But also works without.
The magnets are provided in the original design to keep the two front doors of the NAS closed. If you use a screw to attach the doors, however, the friction is quite enough to hold everything in place. Also, magnets near hard drives are not a good idea.

All parts from Aliexpress listed on this and the other pages can of course also be bought on eBay, Amazon or just locally if you don’t want to wait that long. However, if you order a lot of small parts from AliExpress, you can often get them quite quickly via “Combined Shipping”.