Soldering Stations Expensive but Handles are Cheap!

[SuzyC]

Should I also post this under "Repair" a new forum topic?

My questions is three questions. I like to build my own equipment to save money and I need a new soldering station or at least a handle. I don't like the $100-$150 price of a new Hakko station when I think I can use the old parts left over from my dying station to make my own if I buy a good handle. After 14-years, my old analog handle is falling apart, even though the original tip is still well-tinned and working fine.

Fact 1: I must build my own controller, the old iron used a thermistor instead of a thermocouple for temp sensing. I assume the Hakko models all use a thermocouple for sensing.

Question 1:
Does anyone know if what vendor of Hakko soldering handles selling for less than $10 on Ebay are the real thing?
Do they have silicone cables and Hakko ceramic elements. They look like the real thing.

Question 2:
Are Hakko soldering tips long-lasting and easy to buy?  Always a problem with soldering handles: the availability, life and price of replacement nibs. My old soldering handle tip has lasted 14-yrs even though I did tons of removing old parts from salvaged equipment and built all my many projects with it! Before that I had a Weller TCP station that would lose its tining quick, I used up a tip a month just because I left the iron on, not even using it most of the time, while I worked on my projects.

Question 3: How hard could it be to breadboard a temperature controller using the thermocouple output of the handle?
Should be easy to make my own soldering station with the transformer left over from my dying analog soldering station.

I think I can I think I can!

It seems all I need to do is breadboard a thermocouple amplifier, gain of two series op amps approx 500, even just using a LM358 amplifier and then feed the output to A2D input on my PIC 10-bit A2D MCU, and with a stable reference of the PIC A2D I should be able to adjust the on/off time based on low/above temperature of the iron tip thermocouple. I then shut off the PWM or phase control of the heating element, wait a few millisecs and get a reading every tenth of a sec.

 After all, soldering is a little like cooking, soldering does not need to keep the temperature precisely at the melting point, a few degrees above and dithering about should work, or so I think!

I have bouht a thermocouple type replacement generic analog handle(sans controller, I bought it because I just needed the handle parts to repair my old crumbled handle) and I see about 7mV of output voltage(just needs a little amplification before a2d'ing it) around the melting point of eutectic Pb-Sn solder, so what's the problem to get something to work with a simple pot to adjust the tip temperature?

What about this one?
http://www.ebay.com/itm/FM2028-24V-70W-Soldering-Iron-Handle-for-Solder-Station-FX-951-Eesy-replace-/291335240078?pt=LH_DefaultDomain_0&hash=item43d4eef98e

Or this one?
http://www.ebay.com/itm/HAKKO907-Soldering-Station-Iron-Handle-Soldering-TIPS-Welding-cleaning-sponge-/181571139172?pt=LH_DefaultDomain_0&hash=item2a467bb664

[amyk]

1. Probably not.

2. Depends how you use them.

3. Some use a thermocouple, some use a thermistor. Genuine Hakko uses a thermistor but many clones opt for the cheaper thermocouple sensor. If you look around on this forum you'll find some schematics of both the original Hakko 936 and various clones. Also tons of info here (just search for "936 soldering iron driver).

[SuzyC]

Thanks for the answers, Amyk.

I think making a thermistor-based controller would be just as hard/easy.

I searched but can't find any schematic for controllers on this board for Hakko? These use a high-frequency AC to power the tip?
I am not interested in making something that is very complicated. 60-Cycle AC should be able to do the job for me.

[Psi]

You can get a no-name/copy soldering station for like $40 and slap a genuine Hakko tip on it for really good results.

The tip really is most of what makes an iron good.
The rest is ergonomics and general build quality.
Even the clone/copy irons have plenty of heating power for typical soldering.

The really cheap stations do tend to have cheap ceramic heaters, which can break, but as long as you don't go ultra cheap they are usually ok and replacement heaters are cheap anyway.

If you want to build your own maybe get one of those ultra cheap $19 soldering stations from hobbyking. The iron part is shit but you can use the case/transformer from it, even if you have to make your own control electronics.
Then buy a reasonable quality replacement iron from some other brand and design it to work with that.

Just make sure whatever you get can take the iron tips from a good brand.
Hakko 900M / T18 tips are very common and compatible with lots of clones.

[SuzyC]

I don't know where to find a $40 cheap soldering station.

Do you know what is the best for this price and where to buy the best one for this price?


Second issue, I find just a few sites selling soldering stations, but the sites selling soldering stations rarely sell nibs or don't tell if they are able to use Hakko nibs!

[dannyf]

The fakkos sold on ebay are all solicone sleeved and with ceramic heaters - unlikely genuine hakkko heaters.

No, it is not difficult at all to come up with a controller.

However, you first will need to know which type handle you have. there are three main types, due to sensors used:

1) resistive sensors: those are usually 907 type handles, but I cannot remember if they use male or female connectors (5-pin). 4-wire heater element.
2) thermal couple sensors: also 907 type handles but with a different 5-pin connector. 4-wire element.
3) thermal couple sensors, but use a 3-wire element (T12 type handle) where the sensor is in serial with the heater element. The first of your link is like that.

There are many plans floating around for those handles. The one with resistive sensors is fairly easy to deal with, a simple comparator with on/off logic is more than sufficient. The thermal couple elements need amplification.

I have breadboarded all of them, using a 12F675, plus 5532 for the thermal couple sensors. PID makes little difference due to long time constant of the element + tips.

[SuzyC]

Hey Experts!

How about this one? The whole cabbage.

http://www.ebay.de/itm/Yihua-939BD-75W-Soldering-Station-SMD-Lotstation-Lotkolben-Hakko-heater-/321606107462?pt=DE_Haus_Garten_Heimwerker_Elektrowerkzeuge&hash=item4ae137c146

Another Complete:

http://www.ebay.de/itm/Regelbare-digital-Lotstation-Lotkolben-150-450-C-ZD-931-ESD/400594216144?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140117130753%26meid%3Dbdc3fa2c539d4f4dbedbaa0db3f3f9bb%26pid%3D100005%26prg%3D20140117130753%26rk%3D1%26rkt%3D6%26mehot%3Dag%26sd%3D161457061158&rt=nc

Anyone tried to handle this?

http://www.ebay.de/itm/Lotstation-Eisen-Griff-Soldering-Station-Iron-F-HAKKO-907-ESD-907-936-937-928-k-/301050757838?pt=DE_Haus_Garten_Heimwerker_Elektrowerkzeuge&hash=item46180602ce

[dannyf]

How about this one?

What about it?

[dannyf]

I can probably lay it more bare for you:

1) if you can make it, it is not difficult to make;

2) if you cannot make it, buy it;

3) if you buy cheap, expect cheap quality;

Pretty much universal,

[SuzyC]

Dannyf, I can make it, but I would like to know more about the parts I would make it with.

What I am  hoping is that someone might have bought one of these items and could relate their experience. Sometimes you get something good for cheap, buying wine is like that, and higher price doesn't always increase quality and economy items are sometimes a good choice.

Having heard from someone who has already experienced buying any of the above items could very much help to make the right decision, otherwise I am buying the pig in the poke.

I must make a decision today if I am to give myself a Xmas present:

http://www.ebay.com/itm/Digital-LCD-Power-Comfort-Soldering-Station-Adjustable-New-Product-/381058706006?pt=UK_Home_Garden_PowerTools_SM&hash=item58b8de6a56

Hope it works!

[dannyf]

I haven't used any of those specific stations so I couldn't tell you how the particular ones would work - even if I had used them, they are supplied by no-name places and there is no assurance that two identical looking products off ebay are indeed identical.

With that said, buying off ebay is risky and I think any buyer is best served to manage his/her expectation accordingly.

Good luck with your purchase.

[SuzyC]

The station I bought reaches Pb-Sn soldering temperature maybe about 3 x slower than a Hakko 888D,
I don't like that.

The Hakko allows a password, software that could possibly lock me out of setting the operation or use of my own soldering iron. There is always a chance I might somehow enter into this not needed software booby trap by accident with just two buttons to fiddle with.
I really don't like that.

It is also half the price and sits in a big cabinet 
This means it might be easily modified or repaired or hacked.
I like that.

The small size of the Hakko 888D means there is no possibility, just no room for hacks, modifications or fixes once the warranty runs out and a failure occurs.  No schematic is available.

The handle of my choice has a Hakko schematic available on Google that certainly works with this handle. This means
I can repair or modify having this valuable insight into its operation.
I really like that.

My choice also shows the actual temperature versus target temperature at a glance(hakko requires a button press or two to do the same thing).
I like that.

The station might even be able to be hacked to use a higher power Hakko handle or transformer with a higher capacity to heat more rapidly.
I like that.

I realized that I didn't like attempting to design my own soldering station to my preferences when I don't have a soldering station that is working well enough to to work on this project! So I bought the whole banana and get to get on with my other projects.
I like that!

[paulie]

It's odd that nobody has mentioned the most important item to consider... iron plating. Without this tip life is orders of magnitude shorter. Always test with a magnet before buying.

Also worth noting that soldering "stations" are a relic of the past. Very popular with foolish hobbyists and even professionals here in the USA who have money to burn. Basically no more than extremely overpriced holders. As most chinese factory workers know there is little point in using anything fancier than these Hakko clones:

http://www.ebay.com/itm/171421165042?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Highly controllable and stable temperature with elements and tips that last years even with daily use. Assuming you don't use them to chisel concrete.

[SuzyC]

Its the holdays..I may be a little tipsy..but I am not even being ironical, bit even with a tip, how do I get them to find the iron in
my iron?
I can't even get my boyfriend tp find the lead in  his pencil.

[dannyf]

The station I bought...

Many of the "issues" you mentioned there are non-issues.

However, it is important that you pick an approach that is appropriate with your skills and goals. In this case, you seem to have found the right solution for you. Just hope that it meets your expectation.

[paulie]

Its the holdays..I may be a little tipsy..but I am not even being ironical, bit even with a tip, how do I get them to find the iron in my iron?

Like i said...

Always test with a magnet before buying.

As for boyfriend the more important question is... "is there lead in his solder?". Most techs learn the hard way new ROHS stuff is terrible without it. Lacking eutectic it's slow to solidify and don't flow as well. Some ventilation helps with health issues.

[MrAl]

Hi,

I guess you bought a station already then?

Well the iron 'handles' are not that difficult to understand, at least not the common ones.

The two i have examined are the 907A and the 907F.

First, the 907A is not 60 watts and it is not even 50 watts, it is 36 watts.
The 907F is 50 watts.

They both have 5 connections, two for the heating element, two for the temperature sensor, and one for the metal of the tip housing so it can be grounded.

The 907A has heat element cold resistance of about 16 ohms, hot it's not too much different, so at 24v (the operating voltage) it puts out 36 watts.
The 907F has heat element cold resistance of about 4 ohms, but hot it is around 12 ohms, so at 24v is puts out 48 watts.

The 907A has a thermocouple sensor, the 907F has thermistor.
The 907A thermocouple cold 'resistance' (just for a quick test) measures low ohms like 1 to 3 ohms.
The 907F thermistor resistance cold measures around 50 ohms and it is a PTC type.

To measure the tip temperature with the 907A thermocouple you have to amplify the DC voltage coming out of the tip.  It is very very low when cold and maybe roughly 10mv when hot, so that needs a lot of DC amplification.

To measure the tip temperature of the 907F thermistor you have to supply a reference DC voltage to the thermistor in series with a fixed resistor and measures the voltage divider voltage.  Alternately supply a current and measure the voltage.

In both cases the voltage is compared to a voltage set by the user turned potentiometer that sets the temperature that the user wants the tip to be.  This signal then becomes the error signal.  When the error signal is say positive, the heat element  is supplied with more energy, when the error signal is opposite (negative or zero in this case) the heat element is turned off.

Energy is supplied to the element in the form of an AC voltage, 24vrms.  A triac is turned on and off by the comparison signal via an opto coupler.  The opto coupler turns on and off at the zero crossing so the element always gets a complete half cycle.

It is also possible to run the iron element at 24vdc.  The element can be turned on and off to regulate the temperature.  For testing, the element can be run for a few seconds to make sure it can get hot enough to melt solder.  Whether or not you can run it at the full 24v forever or not i had not tested.  In normal operation with a controller it turns on and off quite a bit.

The thermistor resistance (907F) can be measured when hot by unplugging the iron and quickly using an ohm meter.
The thermocouple voltage (907A) can be measured when hot by unplugging the iron and quickly measuring the DC voltage of the thermocouple, but it will still be low like 10mv.

In the soldering stations, they use a 26vrms transformer to power the element knowing they will loose some voltage with the triac to end up with 24vac for the heating element.  The sine may flat top somewhat due to skimpy transformer design where there are only just enough primary turns on the transformer to barely meet the saturation spec of the transformer core material.

So a controller for one of these two irons is the simplest thing to build.  If you have a 24vdc power supply rated for about 1.5 amps or above you can run a 907A and if you have a 24vdc supply rated at around 2 amps you can run the 907F handle.

[jeremy]

Its the holdays..I may be a little tipsy..but I am not even being ironical, bit even with a tip, how do I get them to find the iron in my iron?

Like i said...

Always test with a magnet before buying.

As for boyfriend the more important question is... "is there lead in his solder?". Most techs learn the hard way new ROHS stuff is terrible without it. Lacking eutectic it's slow to solidify and don't flow as well. Some ventilation helps with health issues.

I'm not sure which rohs solder you are using, but all of mine is eutectic. Try SN100C.

[dannyf]

they use a 26vrms transformer

The OEMs have gone down that path, and I have gone down the path of using laptop power supplies - with great results.

However, it is entirely possible, and I have seen people doing this, to use a triac to control power to the heater element. The whole set-up would be almost identical to mcu-controlled dimmers, with digital read-out for temperature.

Littlefuse has an appnote on how a mcu-based mains-powered dimmer can be done and I think it can be easily modified for this purpose.

[dannyf]

Here is one such handle: http://www.ebay.com/itm/AC-220V-OFF-200-C-480-C-70W-Digital-LCD-Thermostat-Soldering-Iron-PEN-EU-plug-/321083819839?pt=LH_DefaultDomain_0&hash=item4ac216473f

Digital temperature setting and all in one.

It differs slightly from the ones I have seen but the basic structure is the same.

[calexanian]

Just save up a few pennies and dimes and buy a real one. For the sub $90 US they cost your time is worth more than fooling around with a project. Your iron is not something you want to skimp on. Its like saying you want to drive highway speeds on roller skates. It might work for a while, but just do it right.

http://www.all-spec.com/products/FX-888D.html?gclid=CLXGkqf36cICFQpsfgoda7EAyQ

There you go. All pretty and new.