https://www.eevblog.com/forum/reviews/hakko-ft-720-automatic-tip-cleaner/msg5651667/#msg5651667i got one from aliexpress for $88 shipped.
compared to yihua 200C that i got for $50 from amazon: i would go for the aixun cm30, no question. the build quality is better. the window is nice so you can see what you're doing. it also has a larger aperture for easier maneuvering. i prefer the arrangement of the brushes on the aixun, and also it feels a bit draggier (so perhaps stronger) which was surprising because the bristle density on the yihua looks higher. maybe the gap between the brushes is different or something. the tip sensing seems a little more responsive on the aixun as the yihua uses IR. the actual cleaning performance is about the same though.
it uses capacitive sensing or something for tip sensing, and it's plenty sensitive. it actually detects the iron tip (or a screwdriver or whatever) just outside of the aperture, and it will also detect a finger or other metallic or moist things. i did not find that it was oversensitive or twitchy. it just works well.
i am 'impressed' with the mechanical engineering. it doesn't seem like they were optimizing super hard for cost, and i chuckled several times as i took it apart. it seems overbuilt and too well made for what it is. i wonder if the performance or the UX is in any way worse than a fancy tip cleaner from JBC. never used one of those.
not sure why they used off sizes for the hex fasteners. i think they used 1.5mm and 2.5mm. wtf.


brush arrangement:

aixun:

yihua:

as you look at the pics, take note of how the solder chamber is well isolated on the aixun. because of the gasket material, i don't think there's much chance of solder particles going where they're not supposed to.


main pcb:



amusingly, the motor pulley and brush bearing stuff is totally sealed inside a milled aluminum block. they use NSK ZZ bearings on the brushes. i'm generally impressed with all the metal parts in this build. well finished, chamfered, deburred. they use thread locker on the main fasteners.




the magnets for drawer latching are mounted to the aluminum motor/brush block:

i lol'd when i noticed that the drawer was actually made out of steel (to stick to the magnets). i guess they finished and painted it to pretty closely match the look of the aluminum body's anodization. steel drawer on left, main aluminum chassis on right:

here's a shot of the main body. one solid piece of aluminum. i guess they extruded that and then did follow up milling operations? i don't know much about DFM, but that doesn't look cheap at all to me. i'm surprised they went with this method of construction, but it looks sweet. maybe someone with more manufacturing experience can comment on this.

here's a closeup of the sensing flex pcb near the aperture. you can see they goobered it up with silicone, but not quite well enough for my taste. i put a dab of whiteout (correction fluid) over the exposed pins after i looked at this pic:

some before and after tip cleaning shots. normally, i would not run them this long in there, but i wanted to see how much crap it could scrape off:


