Review of Aoyue 850A++
Like many "engineering types", I sometimes attempt to repair modern equipment at home. I have a Metcal iron with various bits, and a Pace 'solder sucker', for traditional PTH constructed equipment.
The problem comes with surface mounted components. Up until now I have made do with soldamop, carefully separating the IC from its legs with a scalpel and then removing the legs with an iron or “flooding” the component off its pads with tons of solder. At work we use a Weller hot air pencil attachment, connected to a comprehensive rework station (soldering iron, solder sucker, hot air pencil).
My own personal experience with using both the “cut and hack” methods at home and the hot air method at work is that results are consistently better using the hot air pencil. There is much less likelihood of ending up with a PCB festooned with Kynar wire repairs ! So the decision was made - it was just a matter of finding a rework station. The obvious place to start was with Pace, Metcal and Weller. Considering that the equipment is quite basic (element, diaphragm pump and a bit of electronics to control air flow and temperature) I didn't think it was going to be expensive – WRONG !
It was impossible to find new kit from any of the professional manufacturers at anything less than many hundreds of Pounds. Quite ridiculous money for a hobby business. The payback time would be immense!
Gloom and doom set in, and the whole idea was almost shelved. However, idly clicking through eBay, I noticed some very cheap equipment. When I say cheap, I’m talking at sub £100, and in some cases sub £50. My first reaction was that it can’t be much good for that price! I did a bit of investigation and “digging” on various forums. It seemed that this kit isn’t actually too bad – certainly no tales of horror. I took the plunge and ordered an Aoyue 850A+ from Allendale Electronics:-
http://www.pcb-soldering.co.uk/
The price I paid was £64.95 (inc Vat) (I have no connection with this company other than being a customer). The kit arrived promptly. What I was actually supplied with was an Aoyue 850A++ (note the extra “+"), not sure what the difference is! I also ordered X2 spare elements at the princely sum of £12 each. As an aside, a new hand piece recently bought for the workplace Weller unit cost nearly £300, we couldn't’t just buy the element!).
Anyway, I decided that it would be a good idea to take a look inside the unit before powering it up. The internals are well laid out, the control board looked pretty basic (and therefore repairable !) using discrete PTH components. The pump assembly was mounted on soft rubber mounts, and 2 parts of the assembly were held together using sturdy cable ties – Hardly top of the range engineering, but nothing seemed about to fall apart !
Pictures of the outside and inside of the unit can be seen in the left hand margin.
I reassembled the case, and then tried to work out how to attach the hand piece rest. The manual offered no clues and there were no spare screws. Eventually I worked out, you have to remove 2 screws from the case, and use them to fasten the holder on.
I then did a full earth bonding and insulation resistance test. Everything passed. The metal parts of the hand piece are also earthed. When the unit is powered, both the air pump and element come on together. There are no controls on the hand piece or a foot pedal. There is a power switch and 2 rotary controls on the front panel, one for temperature and on for airflow. Both the front panel rotaries are calibrated with arbitrary 1-8 graduations.
The heating up period was fairly rapid with the temperature control set mid range. Indication that full temperature has been reached was given by a temperature LED. The LED remained solidly lit during the heating up period but flashed when the set temperature had been reached and was being maintained.
The unit is (naturally!) of Chinese manufacture and is a rough “clone” of a Hakko unit – at a fraction of the cost. Apparently the tips are interchangeable with Hakko, although I haven’t personally verified this.
In use, the air flow was more than adequate . The unit comes with a range of nozzles which are suitable for most uses. Specialist nozzles are available for specific IC’s (not supplied) if you prefer to use these. I personally don’t like them having tried that arrangement on other equipment. With the nozzles supplied, I managed to successfully de-solder a range of different components from a scrap PCB without setting fire to anything. When the unit is switched off, the pump still continues to operate for a set time. This is to “purge” the hot element and prolong its life.
In summary
In my opinion this unit should certainly be a considered purchase for the hobbyist. It would also suffice for the small professional workshop. If I am being brutally honest though (and grossly unfair, given the cheapness of the unit), I find the lack of control annoying after using more professional equipment. Generally with the expensive units, you have an on and off control on the handset, and the pump is off when you don’t require the hot air. No purge period is require when you have finished. This must be down to the design of the element in the respective types of unit, and may go a little way to explain some of the price differential.
The longevity of the Aoyue 850A++unit is an open question, but at the current time (2009) a full range of spares are available. Spare part numbers are detailed in the manual. Like the complete units themselves, spares are cheap. If you decide to purchase one of these units, I would recommend laying in a store in case availability becomes more difficult in the future.
All in all then, though a competent unit that I would recommend to anyone who wants hot air rework capabilities but can’t justify the cost of buying a professional unit.
