Newbie seeking help: enacting a JBOD against a Terraserver, and how to do it

[SkedAddled]

So, here's the deal:
I have a TerraMaster F-410 NAS device, but I don't really like it for what it does,
and I'd like to build a JBOD device with the drives installed in it
and add the 6Tb pair of drives I had from before.

I have an Intel Core i-7 3770K system motherboard with plenty of RAM from
my last system upgrade to an i-7 10700 system, so how would I best turn that
system into a FreeNAS/TrueNAS system for my network?

I'd actually like to build a total FreeNas/TrueNas solution as I see fit,
without any sort of outside influence which tries to tell me what I SHOULD
or SHOULD NOT do.

So, seriously, am I chasing a pipe dream, or is my goal acheivable?

How do I turn the old system into a JBOD system?

 

[i386]

or is my goal acheivable?

It is possible, yes.
The question is how much time and effort (and money) you want to put into such a project.

How do I turn the old system into a JBOD system?

Looking at the pictures from the review here TerraMaster F2-210 NAS Review Layout, design and features
- remove existing backplane
- use adapters to power hdds/ssds
- route sata cable to back (or whereever you want the connectors to be)
- connect the "jbod" to a host system via sata cables

Some problems that I see:
- how to get power from the psu without the mainbaord
- sata cables have per specification a max length of 0.7m
- sata signal over long distances and multiple connectors/adapters
- "ugly"/frankensteind modified nas case

 

[SkedAddled]

I think you misunderstand, likely because I failed to include some information.
I apologize for that big error on my part.

While the TerraMaster box has done well so far, I'd like to turn the old system into a JBOD.
That system includes the above-mentioned i7-3770K on a motherboard,
along with a spare mid-tower case. I had no intent to repurpose the TerraMaster box,
only to use it later as a system-backup destination.

The i7-3770K system is populated with 16Gb RAM and needs only a PSU.
It was a working system when it was mothballed.
It can be installed into a spare mid-tower case at any time.
I have spare keyboards and mice and monitors as needed to do initial
setup as a stand-alone system if required.
The mid-tower case has space for no less than 8, 3.5-inch HDDs,
with room for another 4 or so SSDs and a couple of 5.25-inch optical drives.

My thinking is to add a SATA 6- or 8-device PCI expander card, high-power PSU,
drives(HDD), install TrueNAS as the OS, and go from there.
Other PCI cards can be added later as needed or desired.
A small-ish(512Gb) SSD would carry the OS.

Ideally, I'd transfer the pair of 10Tb volume from the TerraMaster, add the pair of
6Tb drives for system backups, then be free to add/change/upgrade the storage
as needed or desired. Or the pair of 6TB could go back into the TerraMaster
as a backup-only box.

The above would do me just fine, but what about a hot-swappable option
without delving into rackmount chassis? The mid-tower is a great form-factor
for me, and it might likely accept some hot-swap docking.