I've had a CJ18 for the past 9 years, bought it second hand from someone who bought it new from amadeal a year before that (he used it to make parts for his life size dalek, then sold it on)
Sure i sometimes wish i had a bigger lathe with more features like power cross feed, screw cutting gearbox and all that, but this little lathes done all i needed really.
Things i've had fail / go wrong on it,
About a year after i got it i started having problems with it cutting out, refusing to start etc,
I traced this all to the interlock board (amadeal call's it a filter board) that is in the base of the controller box, this makes you start the lathe by turning the speed knob to zero every time… very very annoying,
It also provides motor braking, and operates the inhibit function on the speed controller, which shuts power to the motor if you disconnect the motor whilst running… which you do when you operate the direction switch (something you shouldn't do on any running lathe anyway)
I was told by a few people that those boards can be a pain, and some needed to replace theirs every year or so!! So i bypassed mine, had to keep it in the lathe tho as it also provides power for the speed readout, so that's all it does on my lathe now.
i can get braking and inhibit functions back using a relay and a resistor, i just need to get round to it.
The high – low gear broke about 5 years ago, i lost low speed, it's a set of plastic gears in the headstock, needing the spindle removing to change, so i lived with only high speed for years,
When i finally bought a replacement set of gears, i got the upgraded metal ones,
And at the same time i bought a pair of angular contact bearings to replace the standard ball bearings that the spindle runs in
I figured as i had to pull the spindle and the bearings to get to the gears, i'd do the bearing upgrade at the same time, i got the bearings from arc euro trade (but watch out as most other parts are not interchangable between the seig and reel bull lathes as i found out recently)
When the lathe was put into storage for a year, the person carrying it from the car tripped and the cross slide leadscrews handle got snapped off, to fix this i needing a new leadscrew… so i ordered one from arc as it was cheaper… but it's not the right one, same thread by different on the area that goes through the bearing block / dial and that.
And i had the motor drive pulley come apart and damage itself, again i bought a replacement from arc as it was cheaper than amadeal, but it was not suitable for my lathe (9.5mm hole with keyway, where as the correct part has a 8.5mm hole and a key that's part of the plastic molding)
I've stripped the lathe down a few times and done some fettling to it, there is a great article on how to do this… using a seig version, but as you are just stripping, cleaning and fettling then adjusting it's relevent to most mini lathes:
Mini Lathe Strip and re-assemble