Kitbashed Resistance Soldering- Ideal for N scale

[LV LOU]

Max,as far as I remember,all common colors are common to their connections,so all reds are together,all yellow,ETC. One thing you really have to watch on these power supplies is the amperage rating.The 5V+ is the highest rated voltage on them,because the 5V+ is the section that actually powers everything,CD drives,hardrives,floppies,ETC.Older supplies have much higher ratings.I have one right now that has a 40 amp rating on the 5V+ connection,but the 5V- is only like 2 amps!! And when they say TWO,they mean TWO.You exceed that rating for 15-30 seconds,the entire supply becomes nothing more than a very complex muffin fan.When I build this,I'm gonna put a fuse in it rated at maybe 35 amps.
  I think the way to go here is,start with trying to heat something like a thin railing,the smallest thing you'll ever do.You can get 100 Watt variable resistors on Ebay for about 20 bucks,basically,a huge,copper wound Potentiometer.I'd hook the main from the supply to the center wiper.Now,to establish a base,and reduce the load on the resistor,I'd run a wire from the right terminal.This would be one power feed out.To the same terminal,and the same output of the suppy,and it would take a little messing around,I'd get some big power resistors,and get the ohm rating just right so that with the variable resistor off,it would just solder the railing..This would set up you minimum baseline.and put load on cheap resistors,instead of a fairly expensive rheostat.
  Now,same idea,same terminals,I'd add a few SWITCHED resistors that equal about half the output of the variable rheostat,so you can do heavier stuff,once again,without killing the rheostat..Actually,if it was say,a 100 Ohm stat,you could jump it in 3 steps of 25 ohms or so.[Don't want the rheostat glowing now,do we?] I'd also try to get a decent amp meter,so you can test whether you're exceeding the amp limit of the supply.
 I think you could get a pretty decent carbon by getting a big,honking carpenters pencil,and just take a torch on low heat,and burn off the wood,if you wanted to go that way,I think I'm gonna use some 1/4 copper ground rods I have to make a tweezer type setup.Also,I'm gonna build a seperate unit in an old power supply box to house the resistors,stat,etc,and keep the old fan in it so everything stays cool.

[alhoop]

Not to beat a dead horse but John Paige described a resistance soldering system he built in Model Railroader November 1954.
He used a 8-10 amp 6.3 vac transformer.

Al

[u18b]

Max,
As was stated, all colors appear to be tied in at the same spots on the board.

Lou,
My local welding supply company (where I buy my bottled N2 for airbrushing) are very helpful.
When I was in a week or two ago, I told them what I was doing.  The guy couldn't help much... but he tried.  For free, he gave me one welding rod.  It is solid carbon with what looks like a copper coating.  If I remember, he called it a gouging rod.  It is really big for the delicate work I want to do... but it seems like it would work.

Alhoop, Thanks.  I might be able to look that up.

[peteski]

Max,
As was stated, all colors appear to be tied in at the same spots on the board.

Lou,
My local welding supply company (where I buy my bottled N2 for airbrushing) are very helpful.
When I was in a week or two ago, I told them what I was doing.  The guy couldn't help much... but he tried.  For free, he gave me one welding rod.  It is solid carbon with what looks like a copper coating.  If I remember, he called it a gouging rod.  It is really big for the delicate work I want to do... but it seems like it would work.

Alhoop, Thanks.  I might be able to look that up.

American Beauty sells 3/32" carbon rods with copper cladding (as a consumable part).  https://www.americanbeautytools.com/Resistance-Soldering/144 . But for even more precise resistance soldering you might want to try making tweezers and using stainless steel electrodes https://www.americanbeautytools.com/Resistance-Soldering/146 .  Those are the ones used for very fine work.  The prices are not outrageous and those items are designed for the specific task you would use them for.

LOU: in order to be able to successfully control the amount of current passing through the items being soldered you need to control the output voltage.  That is not something that can be easily accomplished in a computer power supply. Even if there are trimmer pots, they usually only give you a small range of control over the output (not from zero to the max voltage).  I still don't like the idea of using filtered and regulated output of a computer power and basically shorting it out.  But that might just be me.

EDIT: the URLs I used are simply to show you the items. You should be able to buy these even cheaper going through a distributor (rather than direct from American Beauty).  I still can't help but to chuckle at their name. 

[LV LOU]

Max,
As was stated, all colors appear to be tied in at the same spots on the board.

Lou,
My local welding supply company (where I buy my bottled N2 for airbrushing) are very helpful.
When I was in a week or two ago, I told them what I was doing.  The guy couldn't help much... but he tried.  For free, he gave me one welding rod.  It is solid carbon with what looks like a copper coating.  If I remember, he called it a gouging rod.  It is really big for the delicate work I want to do... but it seems like it would work.

Alhoop, Thanks.  I might be able to look that up.

Ron,I'll stop at the shop near me as soon as I get a chance..

[Lemosteam]

Hi.
I decided to move the discussion from the New EP-2 thread
https://www.therailwire.net/forum/index.php?topic=31042.0

Since this is really a new topic (worthy of searching and archiving in the future).

Eventually, the mods will want to move this, but maybe it can stay for a little.
I trust their good judgement.

I started by.....
----------------------------------------------------------

I finished building a Resistance Soldering Station.



It was much more involved a project than I thought.  Not the device, but all the photography, and thinking, and writing.  It is 31 pages- which sounds like a lot, but my hope is that it is VERY clear.  Magazines just can't do something like this.

So download away.  And enjoy.  I'd love to know if you build one and it works.  I can already see that this will be a very valuable tool in the future.  I've already used it to repair one of my damaged brass locomotives.

http://u18b.com/wp-content/uploads/2013/03/ResisSolder1403.pdf

I tried VERY hard to keep the size under 1 meg so as to reduce my bandwidth hit from my website.

@u18b It appears that the document in the second link os no longer available on your page.

Could you repost the pdf file or attach it to TRW?

[u18b]

Hi John,
I got this idea from someone else and ran with it.
However,  I closed down this project as not ultimately helpful. What I learned is:

1.  The pencil lead does indeed produce high localized heat, but leaves residue which hinders the soldering process.  So it produces heat, but also a greasy residue.

2.  I always had some safety concerns.   This project takes a computer power supply and uses it in a way not designed.  It has overload protection which I tested and works... but it still made me nervous.

I laid this project aside when I bought a reasonably priced American Beauty resistance soldering station.  The difference was staggering.  I especially like the tweezers.   I also like the on/off button and use a foot pedal.

I highly recommend this product.

I watched and bough a used one off ebay.  Models and Prices come and go like all of ebay.  It takes patience.

https://www.ebay.com/sch/12576/i.html?_from=R40&_nkw=american+beauty+-pot+-stripping+-puma+-105159+-10565+-3112+-105133+-bulb+-horse+-43d++-v36gm3+-rqaus1+-105y10+-10549+-3198+-10511+-10587+-pb50+-salon+-rqans1+-flux+-v36gl3+-braid+-conical+-sponge+-irons+-element+-carbon+-iron+-diamond+-chisel+-screwdriver+-stripper+-ultrasonic+-wirestripping&LH_TitleDesc=0&_udlo=9.99&_sop=10&_udhi=245.00&_oac=1

[Lemosteam]

Understood, thanks.

[peteski]

Wow Ron, looking at the link you posted, those are some interesting search criteria you used to find that unit.  I guess with a name like "American Beauty", you have to get really creative to eliminate all the "chaff" eBay dishes out.

[wvgca]

LOU: in order to be able to successfully control the amount of current passing through the items being soldered you need to control the output voltage. 

in my home made version i used to control the amperage for different jobs .. i found the voltage needed to be fairly consistent, around six volts or so ..

[peteski]

in my home made version i used to control the amperage for different jobs .. i found the voltage needed to be fairly consistent, around six volts or so ..

Well, if you understand Ohm's Law then you know that there is a direct relationship between resistance, voltage, and amperage.   If the total resistance of the circuit is not changing, you are actually controlling the amperage by changing the voltage.  I suspect that you understand.  It is all interconnected. If you are keeping the voltage at a constant 6V while varying amperage, then the only way to control the amperage is to change the circuit's resistance.

The American Beauty unit controls the voltage supplied to the power transformer's primary winding. Than in turn produces variable voltage on the low-voltage high amperage secondary winding.  The actual amperage during soldering operation is not the maximum amperage that the unit can supply at the voltage it is adjusted to.  The amperage will be dictated (limited) by the resistance of the circuit's being soldered (the leads, electrodes, and the metal being soldered).  Think of the American Beauty's voltage adjustment as a power limiter.

[u18b]

Wow Ron, looking at the link you posted, those are some interesting search criteria you used to find that unit.  I guess with a name like "American Beauty", you have to get really creative to eliminate all the "chaff" eBay dishes out.

Exactly!   

[u18b]

This is a better search link.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=american+beauty+-3158+-3178+-3600+-8055+-704+-mp9+-pot+-wirestripper+-stripping+-puma+-bulb+-horse+-43d++-v36gm3+-rqaus1+-pb50+-salon+-rqans1+-flux+-v36gl3+-braid+-conical+-sponge+-irons+-element+-carbon+-iron+-diamond+-chisel+-screwdriver+-stripper+-ultrasonic+-wirestripping&_sacat=12576&LH_TitleDesc=0&_udlo=9.99&_odkw=american+beauty+-3158+-3178+-3600+-8055+-704+-pot+-wirestripper+-stripping+-puma+-bulb+-horse+-43d++-v36gm3+-rqaus1+-pb50+-salon+-rqans1+-flux+-v36gl3+-braid+-conical+-sponge+-irons+-element+-carbon+-iron+-diamond+-chisel+-screwdriver+-stripper+-ultrasonic+-wirestripping&_osacat=12576&_sop=10&_udhi=400

[u18b]

I will revise the article and re-post.
Give me a while to get it done.

[u18b]

@Lemosteam

OK, I revised the doc and reposted.

I took my name off of it because I don't want to get sued some day.   

There are also lots of Armageddon warnings.    

It was an interesting project.

https://u18b.com/wp-content/uploads/2022/10/ResisSolder2210.pdf