Have to say I’m on a bit of a roll when it comes to bargain chasing, because my shopping at element14 continues. One tool which I don’t have, and had always wanted, was a hot air rework station. I’m no certified BGA reballer, nor have I got any SMD skills at all, but having one would let me pluck components off boards and give me an easier time trying to solder some of the SMD parts to adapters. It might even give me a chance to salvage and repair some things I wouldn’t otherwise have any chance of doing.
For that matter, I also wanted a decent soldering iron.
I’m sure many people have one of these nasty buggers lying around somewhere. This one was a Super Cheap Auto $7 60W iron I got at 15% off on a sale. This iron probably uses some nichrome wire heating element hooked up to the mains, with no thermal regulation whatsoever. I know this because it takes an age to get to temperature and if you use it for longer than about 30 minutes, it gets hot enough to burn you through the handle!
The tips on those were plenty terrible – so this one I improved by shoehorning in a Weller tip – originally conical, but now worn to resemble a chisel shape. I’ve desoldered the capacitors from over 20 motherboards and replaced them with this iron, and I’ve built many circuits on veroboard and kits as well. Without thermal regulation, it can be a little hard at first to get it right – but I’ve gotten used to its foibles over time, knowing when to give it a little time to recover, and soldering just enough to keep the tip from getting too hot.
This sturdy, primitive iron has done all of my soldering and desoldering since 2004. It’s always been handy, but it’s probably about time I upgraded.
Normally, such SMD rework stations are pricey and out of the reach of a student. I was definitely in for a surprise when I spotted this bundle which includes the Tenma 900W SMD Rework Station, a special in the Connect magazine, going for AU$142.60. It includes a soldering iron and a hot air rework system in the one unit.
The bundle itself seems to include the following (and the corresponding regular prices are):
|2062633||Rework Station 900W 220V UK/EU||226.58|
|2102733||Multicomp YP-35/YC-12 H05VV-F – Mains Plug IEC C13 1.83M Black||2.19|
|5090854||Multicore Solder 2096125-M 60/40 1.2mm 500g||68.04|
|3125634||Duratool 8PK-366D-F Desoldering Gun Antistatic||9.68|
|1156001||Duratool PL-501 Micro Cutter 5″||8.6|
|1616334||Duratool D00837 Tweezers Type 13 SMD SA ESD 120mm||26.62|
That’s about AU$340 of stuff going for $142.60. In fact, just getting the cutters, desoldering gun and reel of solder would be plenty useful for me.
Of course, when you see specials like these, you have to be a little careful – quality is probably not one of their strong points, and with Tenma, things can be a little hit and miss. In fact, just looking at the pricing, even if the station itself was useless, I wouldn’t be losing by much (AU$27.47) – worth a gamble! That’s probably why they’re all out of them at this present time!
The bundle itself came in a box of its own, with the rework station inside the product box.
The box itself was a little crumpled, but hey, it doesn’t look too bad.
The features are shown on the side of the box. There seems to be some evidence of “chinglish” expression in the grey box, referring to the product as “it”, and the strong personification of the product.
The unit inside requires some assembly – the side bracket for the hot air rework nozzle is not attached and must be screwed on. There are mounting points on the left and right side, so you can choose either one. You will also find the bracket itself is magnetic, so it will tend to try and “grab” to the side of the unit when screwing the bracket on – no doubt this is used by the nozzle to sense when it is placed into the holder to go to sleep.
Another assembly step – the soldering iron pencil has to be plugged in and screwed in as well. The soldering iron comes with a thin conical tip, metal stand (impressive) and a regular sponge cleaner (slightly less impressive). Unfortunately, iron doesn’t fit nice and snugly into the stand, and has a habit of backing off a little and tilting upward, resulting in the metal locking collar ring making contact with the stand. It’s not what I would expect to be the best outcome – it would be nicest if the surrounds were nicely snug so that the iron was held in place at the plastic edge so that the heat isn’t being transferred to the stand.
The length of the cable between the rework station and the pencil (and hot air rework gun) is only about 1m, making it a bit short for my liking. Unfortunately, the cable to the soldering pencil doesn’t seem to be burn-proof cable either (it doesn’t feel like silicone rubber, but I’m not going to try and burn it). The hot air rework gun has three buttons on it which allow for changing the temperature and flow from the handle itself, although with the way the tubing is fitted, the gun always wants to have the buttons facing the holder where it can inadvertently be pushed.
The unit looks like a piece of sound and lighting equipment for the stage, black and with a (plastic) carry handle. The front is adorned with a hardware power switch, two LCDs (one for the hot air rework, and the other for the solder iron) and four push buttons. There are individual push buttons to turn on and off the soldering iron and the hot air rework station, and shared buttons to control the temperature, airflow, etc.
The system is microprocessor controlled and employs feedback to ensure temperature regulation. The unit is capable of reporting heater error and sensor error via the LCD in case of failure.
Not pictured – the unit has a fused IEC connector at the rear for power and is supplied by default with only the UK and Euro IEC cables. There is a separate IEC cable for Australia included in the bundled products it came with. The unit itself seems to be rated for 220v by the nameplate – this seems a little odd.
Most products are rated by their harmonized voltage – i.e. 230v. Because it claims to be 220v, I think it’s likely to be (really) a 220v product made for the Chinese market, and its lifetime could be shortened when used in 240v countries. Otherwise, it could be a 230v harmonized product incorrectly labelled.
The quality of the construction of this unit can only be described as marginal to poor. The soldering iron connector is off at an angle, there are outward dents on the top panel, and the power switch is a bit crooked as well.
Anyway, I’ll be happy if it works. Lets take a quick look at the other stuff that it came with – for example, this selection of nozzles for concentrating the hot air when working with particular sorts of SMD components.
Also included is this manual … notice how they misspelt rework on the front cover …
Unfortunately, this is where the “chinglish” sets in, because this manual is really hard to understand, and it makes my head hurt. I still haven’t gotten around to working out how all the presets work … but at least I can change the temperature!
A much closer look at the unit reveals this is a rebadged Atten AT8502D Multi-Function Rework Station. Interestingly, the power is rated as power consumption, and the claims for the rework station is only 550W consumption for hot air and 50W consumption for soldering iron. The numbers don’t even add up. Tenma seem to claim 800W hot air + 40W diaphragm pump + 50W soldering iron, which is 890W despite their claim of 900W. Eh, it’s all marketing …
That being said, you still get more – you get the other stuff as promised in the bundle.
The desoldering gun is of decent quality, although the knob has a tendency to ride out of the rails, easily fixed with a pair of pliers. The tweezers, are like regular tweezers, but have a flat-rectangular shaped end at an angle, to help you grab onto SMD chips, as well as a enamel-like coating on the handles. The flush side cutters work pretty well – I’m quite pleased with the cut. Best of all, the solder is the Multicore stuff, which is pretty much great quality stuff. The 60/40 “leaded” solder seems to be an odd inclusion for a “lead free” workstation, but it is easier to solder with and probably the best stuff for through-hole users with the 1.2mm diameter. In fact, I’m about 90% way through a 250g reel of the exact same thing.
Does it Work?
In a word, yes. It does work. After a bit of fiddling and sighing at the keypad beeps, it’s actually not a bad station. Soldering with it is plenty easy, although the fine tip makes it suitable really only for PCB level work. While there appears to be other tips for the unit according to the manual, their availability seems to be a problem. The hot air rework gun was a bit trickier to get going – once it was operating, the unit hummed much like an aquarium pump and it was possible to desolder some BGA packages just fine … (yes, I ruined a useless RAM stick …)
Setting the temperature and air flow is a bit tricky, and so far it’s really been a bit of button mashing until I got the right settings. The unit does detect when the gun is in the cradle, and will continue to blow air until the temperature drops to 100 degrees C and then turn it off into sleep mode.
How long will it last? I have no clue, but we’ll see. At least it lasted a weekend so far …
Of course, my next curiosity was just what was running the unit and why it was so comparatively big. Taking off the screws around the top shell allows it to be completely lifted off to reveal the insides.
There’s a bit of empty space in here. The big unit at the mid right is the diaphragm pump which provides the airflow to the hot air gun. The pump is the black unit at the bottom, which feeds its flow to a white plastic chamber attached to the top with cable ties (likely to smooth out the airflow). The whole pump and chamber is mounted on rubber suspension and is free to move, to absorb vibration, hence the metal guards attached below and to the left to limit the amount of travel.
Power appears to come in from the IEC connector and goes straight to the PCB line conditioning components. Then it passes through the hardware switch back to the PCB, where it is controlled and directed to the transformer (might run the soldering iron) and the airflow pump and heater element of the hot air gun).
The main PCB is seen here – the power enters on the left side. Interestingly, it’s all controlled by a PIC microcontroller in the centre. The unit does have some puzzling construction choices – middle top, you see two red wires which carry primary power somewhere are supposed to be attached to a connector and are instead soldered to the connector and heatshrinked. That’s not great construction. Elsewhere, the proper connectors seem to be used.
Closer inspection of the transformer seems to give the impression that the unit does employ components designed for 220v, such as this Chinese transformer. The output is a dual winding of 12v at 0.3A and a 19V at 2A winding … not too sure if it’s running the iron, because if it is, then it’s really only giving out about 38W (RMS of course, although it is 53.7W peak due to the AC waveform). I suspect there might be some lies here.
The pump itself seems to be marked AP-251 and is for 220v, and probably about 13W as well, but it’s not awfully clear due to obstruction by cable tie. I didn’t want to risk damaging the device getting the cable tie off, so I’ll just leave it there.
When I saw this bundle, I thought it was the bargain of the century. I’ve never seen any hot air rework station at this price – even most decent temperature regulated soldering irons start at this price. As a result, I couldn’t resist jumping in with both feet.
The product itself seems to be of mixed quality – the documentation is poor, the build quality is marginal, getting to grips with the front panel controls and incessant beeping is a pain and the parts seem to be 220v. This might mean a shorter lifetime at 240v, and isn’t really the best especially if you’re going to be using it a lot. The cables are a bit short, and it seems like there might be some cheating with the ratings here and there.
But it is cheap, and when you’re cheap, you expect these things. And at the end of the day, it does work, and it solders decently. I can’t say I’m not impressed by the price, but the jury is still out when it comes to lifetime and durability.