Build your own temperature controlled soldering station

Hi Cabe,

It is really a great artical. Thanks for the link.

Firat,

Its an interesting project.  However, if you want a good soldering station, it should meet commercial specifications, maintain heat variation ~ + /- 1F for the station and maintain tip heat ~ +/- 10F.  Heaters and tips in quality stations are often made of proprietary materials and add to the advantages of the more expensive irons.  Its not simply a close loop feedback controller on any ordinary heating element and all tips are made the same.  The economies of scale for manufacturing make it cheaper to buy a true temp controlled station than to buy their spare parts and build your own around it.

Saturation,

Post some links to the stations you suggest. (In a new post perhaps?)

Cabe

Happy to help, Cabe.  I'm not sure if people are interested so please feel free to suggest the right subforum.

For home or developer use, that is not in a factory production setting, a basic commercial standard IPC conforming station, bolded ones are a best buy.

$100 [ requires occasional user calibration of the analog dial, provides basic solder station temp control and good thermal recovery even for production use]

Hakko FX 888

Weller WES51

$200 [ at this pricing and up, all are calibration free, and have better thermal recovery]

Oki PS 900

Pace  ST 25 + PS 90

$400+ [ high end many options, fastest thermal recovery]

JBC BD-1BA

Metcal 5000

Conforming to IPC will also meet US military, NASA, and ESA and many agency specifications, and the station itself is not high tech.  A reason for buying such a station over a nonregulated or non-feedback iron is that these standards have already proven that such stations maximize tip life and reduces thermal damage to parts, over the long haul.  They are ergonomic to use, and likely in a single user setting, will last the user a lifetime.  Small components, if soldered with a soldering iron, do not have much thermal mass, and can easily be heated into damage not necessarily visible due to a malfunction during post-assembly testing.  Subtle damage usually shows itself as reduced part lifespan over its expected lifespan.

Of particular importance in reducing temperature is that lead free solder increases tip wear over 3X above 350C.  In leaded solder, tip temp did not produce such stark wear rates.  To know where 350C on your tip, you may have to calibrate it.  A simple way to spot check a tip without fancy equipment is to use eutectic solder; with a sharp melting point and no intermediate phase, it will clearly measure tip temp to set your knobs to the right area.  At 300C, the wear rates converge so even a 50C error, fairly unlikely with eutectic solder, will not be a practical problem for individuals who don't need IPC or ISO certification.

Soldering stations worldwide are dominated by at least, Hakko, Oki/Metcal, Pace, and Weller. JBC and Ersa are good brands, but are priced high for individual users,  and are more common in factories, but deserves mentioning.  There are many regional brands and many variants in products in different countries, what you end up with depends on what they make available or is priced competitively; many EU countries add a lot of tax for importation; in the USA the prices are often lowest.   Since the basic electronic technology is fairly low tech, copies and clones can be made by many, but these makers do not OEM for other brands, AFAIK.  Makers like Aoyue or Atten [ Hakko clones to outright counterfeit, too many makers to count], to house brands like Radio Shack, Velleman, or Duratools etc., may have unknown or unreliable specs and performance, and should be avoided.  Avoid unknown for 4 reasons: the name brands are already well known for quality, the cost difference may be small, original replacement parts are easily stocked and made,  many are used by commercial factories and thus, conform for IPC-J-STD-001 standard.

Xytronic is a strange fellow, its a Taiwanese maker with a reputation of its own, been around over 30 years, but it dilutes itself by making OEM and reports of its own quality can be  mixed, but it has stations as good as low end Hakko with similar specs, for half price. If made available as a choice when Weller or Hakko are not, its worth consideration over a brand without a clear reputation.

Soldering stations wear out tips and heating elements, so spare parts are crucial to the station you buy, a buyer will buy as much into the company as the station to get supplies of parts.  Tip and heater technology is key as while electronics can be easily  copied, mettalurgy is more difficult; tips and heaters can look the  same, but originals have special alloys that give them the properties  you paid for in a brand name, fast thermal recovery and durability.  Many clone or counterfeit Hakkos for example, claim compatibility with original Hakko tips and heaters to suggest you can buy their station and benefit from original Hakko metallurgy.

Lastly on thermal recovery.   While there is no standard test one can use to compare soldering irons across all makes, a simple index is to simply turn your iron on, making sure the tip is truly at room temperature; preferably cool the iron overnight otherwise it will shorten the time artificially.  Since the heating LED or indicator remains ON until the final temperature is reached then blinks instead as it cycles off/on, time how long it takes to reach 350C with a stop watch.  For comparison:

JBC AD2950: 6 seconds

Metcal 5000: 12 seconds

Hakko 936: 43 seconds

Sample JBC versus Metcal

Turn On to stable temp graph

How turn-on time translates to thermal recovery from soldering a typical PCB tab:

Hakko's thermal graph of a 936 versus the new FX888 to show how it compares in thermal recovery against JBC and Metcal.  Note the time scale is very different, but the temp cyles 50C, between 250C-300C, similar to JBC spread.

what about using a LM35

there has been a ton of research done on the subject here http://dangerousprototypes.com/forum/viewtopic.php?f=19&t=3475&start=135&hilit=soldering+iron+driver

Cabe, in the last 40+ years I have gone through many "soldering station" We used to use a Weller but it has temp fixed tips which idle via a temp controlled "snap switch" they produce a lot of impulse noise and aren't good.

after many false starts I ended up with a Metcal which is a pro system and can be picked up on ebay...

http://www.ebay.com/itm/Metcal-STSS-002-Soldering-System-Power-Supply-RFG-30-Solder-Station-/350684716791?pt=LH_DefaultDomain_0&hash=item51a6701ef7

Also I have an aerospace background in soldering.... I a word what I saw of your lack of technique.  You don't ever need to add paste to your work on feed through parts. and never touch the solder to the iron instead hold the iron to the work and then touch the solder to other side of the work and let the solder flow to it.

please look at this link on my old web site for soldering techniques. you want this NASA-STD-8739.3 document on the bottom of the page. also please download the color photos which are not part of the document.

http://www.phoenixcomm.net/~phnx2000/sim/library.shtml

In case you don't work on NASA projects......

Schmartboard sells a nifty kit that is basically a 40W iron and a triac lamp dimmer circuit (part number

I just wrap a 1/2-in length of my fav solder around the tip and turn it up until it just melts (great for tiny smd work).

This iron works better than my $300 Weller soldering station.  Sometimes simple is better.

Scott

Scott, Yes I qualified on the course a long time ago before my work at Hughes Aircraft (satellite div) in LA. What I was trying to say that poor technique will end up with poor results. And so what if you don't work in a NASA clean room. But I do build experimental aircraft that I put my life in.. So I strive for the best that I can do. Yes I am myopic! one of the sayings that we used to say "I'm not going to go on that 25,000 mile service call! remember they did that one for Hubbell ". And beside they say you may be able to take the horse to water... But he may not drink it.

enjoy

Couldn't agree more with Harrison, if you're going to learn to do it, why not do it in the best way?  As for soldering irons, sure triac light dimmer?  Why not just a nail and lighter, even easier, cheap and simple?  The fact is the soldering process has been studied in depth, and best way is the NASA, or MILSPEC or IPC way, everything else has been known to create faulty joints when you least expect it.  Soldering irons are only half the equation, the other half is user skill; before temperature controlled irons existed a lot more was placed on training the operator; the reason temperature controlled irons became the norm was due to studies that showed the effects of no regulation, partial regulation, to full regulation not just joint integrity, but the lifespan of the soldered part.