Sorry to hear it didn't work out with unisolder. Quickly checking that Dangerous prototypes thread, it seems quite some effort was spent, yet it didn't work reliably. I hope your next soldering station will work smoothly, and you'll forget your 5.2 as a nightmare.
PS I use Aixun T3a and I'm quite happy about it (though didn't try to solder anything serious and yet to buy genuine jbc cartridges).
PPS just in case, did you clean your Unisolder board from flux?
Yeah I feel bad for anyone sucked into the unisolder universe. I still see people on youtube comments asking SDG to buy the kit and build it up.
I get the concept, its a great concept, but the end result is just insanely overcomplicated and expensive for what it needs to do. Its more like a soldering iron dev kit.
If you just want to get off the ground, you could get the Aixun or other JBC clone, and use your tips. Some of them use the official handle and connector, some don't, but they come with a handle anyway so... could sell or keep as spares.
Then there is stuff like Aifen A3 and A9 which support C115 handle.
Or Aifen A902 which has dual outputs: https://www.aliexpress.us/item/3256804329501171.html
Please research more, I don't know what the limitations are on these with C115. Other than that for sure you won't get tweezer support. So either, leave that off for now, and just use hot air. Maybe down the road you can fix the unisolder and get it working with tweezers, or build your own design instead.
BTW have you test nano or microtweezers on Aixun T3?
I do run a Macbook and Laptop repair business in Adelaide, where I work mostly on 0201, 0402 size SMD components.
I have good news for you, OP. JBC AN115-A nano tweezers can work with the Aifen A902 dual soldering station.
Recently, I snapped up a good deal on the tweezers, figuring that I'd never get another chance to buy it that cheap again. After some experimenting, I was able to make a Binder-to-Hirose adapter to connect the nano tweezers to my A902. A lot of these JBC clones seem to use the same wiring scheme for their Hirose-style "aviation" plugs, so it should work with any Aifen or Sugon JBC clone that can supply enough wattage to simultaneously power two C115 cartridges. The A902 is nice because it's a 350W station and supports C115, C210, C245, and even C470.
What's so annoying about the AN115-A is that it uses a pricey 5-pin male bayonet plug that's only made by Binder. I can't source the female bayonet it mates with because it's locally out of stock. I could order it from Binder USA, but the high cost of the connector and shipping makes it a nope for me. I did eventually find a good deal on a non-bayonet version that I used for R&D and the adapter. But, if I ever have to do it again, I would just remove the unobtainium Binder plug from the tweezers and replace it with a common Hirose aviation plug. Since I don't see myself buying a NASE station ever, it doesn't make sense to spend so much on a Binder product.
The tweezers are working great for me so far. I know some people think they're an extravagant toy, but I've found them super useful at times. They're really nice to have around when you need them.
If anyone's interested, I can also post photos of a hanger and stand for the tweezers that I bent from some 14 gauge solid Romex I had lying around. They put the tweezers into sleep mode.
Heating is fine as long as you have realistic expectations of what they're capable of. These are NANO tweezers after all. They won't work well on boards designed to dissipate gobs of heat. One PCB I tried it on was a USB power source attachment for a power tool battery. It took forever to get 603s off even though the board was tiny (40mm x 50mm). Some larger components near mosfets and other power related regions wouldn't come off at all even with lots of flux and a little help from hot air above.
And phone logic boards are small but engineered for heat efficiency. So, at times you'll need more than flux - like a pre-heater underneath. Other than that, components come off pretty quickly. When I've used it on smaller 2-layer microcontroller boards around 20mm x 40mm, parts come off in about 2-3 seconds.
As for temperature accuracy and response, I haven't done a careful test with thermal loading and recovery, etc. But, preliminary thermocouple readings look stable and close enough to say it's working alright. At least well enough to be useable for it's intended purpose. And I have used it with success for practical work, and for some people, that's all that really mattters. The biggest concern is that this mod sets up the cartridge thermocouples in parallel on the same sensing line. So I'm not sure how that's going to affect the controller's temperature algorithm. So far so good, though. Both cartridges measure virtually the same temperature with no thermal loading.
That unit looks sleek, do you know how it detects what type of iron it uses? I have got 115, 210, 245 irons as part of thekit, but did not saw any resistors in the plug side. Must be detecting the type of iron somehow.
The buttons on the irons are actually quite comfortable. I was pessimistic at the start.
My thought for the DIP switch was this one https://www.aliexpress.com/item/4000925833903.html its 6P2T and can switch all 6 lines between two states. Took some time to locate it, but I can fit one on each side of the power switch.
I am thinking to add nanotweezers and have 2 position manual switch for each iron side, which can alternate between all connected 4 irons. I am just contemplating keeping the hiroshi plugs or using standard aviation plugs instead. Those buggers are 15AUD each and still are missing the two extra pins for UP/DOWN on the iron handle. I don't mind having to manually switch between the irons as long as the switch is on a reachable distance. I have measured the space inside and this will fit nicely.
BTW I am combining my findings on A902 in a github repo so we can hack it around, would it be ok to include and modify some of your drawings?