I just myself a Hakko FR-300 from Tequipment and I find it a joy to use.
It works very well and removes solder quick and clean. Parts just fall off the PCB after desoldering.
I had one gripe though. The LED indicator is a blinking red LED indicating if the heater is on but prevents me from knowing at a quick glance if the unit is on or off so I had to modify it. So I took the chance to take pics of the inside of my unit.
My unit on the workbench
Four self tapping screws and two metal thread screws later, the side comes off.
The tip assembly is mounted to the case with fine thread screws (M3) and metal inserts in the case.
A detail of the air pump crank and bearing.
Power cord strain relief and ground screw. It does not ground the case (obviously plastic) but just to connect the power cord ground to the tip assembly. No shakeproof washers on it.
motor is a DC brushed motor with a PCB at the back which contains a FULL BRIDGE RECTIFIER and a capacitive dropper for it to operate at the full 120V mains.
The PCB lifts after removing two screws.
overview of the PCB, it is a single sided load.
The temp and calibration controls use PCB mounted trimmers.
mod detail and a couple more pics here:
http://quan-diy.com/misc/hakko_mod/fr300.htm