# Resistance soldering machines--need source on carbon rods



## Les (Feb 11, 2008)

By the sheerest luck I've found enough parts to build a ~100W resistance soldering machine. I got the plans from an old NMRA Bulletin. (Would that our modern mags had so much good stuff in each issue).

At any rate, I need a source for carbon rods. And that leads to an aside, namely, there's a savvy electronics guy on this forum who's offered to answer questions, and I've mislaid his name/contact. Can anyone help me there?

The first question I want to pose is the diameter of the carbon rods. To those of you who happen to own one, can you give me the diameter and length? The only carbon rods I have to hand are 1/4" thick, and that seems a tad like overkill, but perhaps not. I'm not clear whether the face of the rod should be flat or pointed. It's for heat transfer, and not a consumable, as I gather it. I'm also wondering if common round tool-motor brushes would be suitable?

Your thoughts and help would be appreciated. If all else fails, I'll blind-order a set from Micro-Mark. It's the diameter that is the only number I'm lacking.

Les


----------



## weaverc (Jan 2, 2008)

You can usually find carbon rods at a welding shop. Ask for Carbon Rod,1/8” diameter (Arch Gouging Carbon). They usually come in bulk at $15 per 100. 
Until you find a source, try this. I've found that it works. 

You can make a carbon rod from the guts of a standard, el-cheapo, alkaline, ‘D’ cell battery (carbon cell of course and not Nicad, NiMH or other rechargeable types). I found that the cheaper the battery the better. Name brands like Eveready or Duracell tend to have soft carbon rods that are pourous. The really cheap ones, like the off brands you get in a supermarket or with Chinese toys, seem to use much harder carbon. A hard carbon will last longer with resistance soldering. Take care when cutting a dry cell battery open because it can be a messy job. Use some sand paper or an old fashioned small plastic pencil sharpener to file a conical tip onto the working end of the carbon rod.


----------



## Les (Feb 11, 2008)

Thanks, Carl.


That battery idea I like, at least until I get practiced up. (I know how to solder with an iron and torch). Now, where's that dead flashlight?









Les


----------



## toddalin (Jan 4, 2008)

Posted By weaverc on 01/07/2009 7:29 PM
You can usually find carbon rods at a welding shop. Ask for Carbon Rod,1/8” diameter (Arch Gouging Carbon). They usually come in bulk at $15 per 100. 
Until you find a source, try this. I've found that it works. 

You can make a carbon rod from the guts of a standard, el-cheapo, alkaline, ‘D’ cell battery (carbon cell of course and not Nicad, NiMH or other rechargeable types). I found that the cheaper the battery the better. Name brands like Eveready or Duracell tend to have soft carbon rods that are pourous. The really cheap ones, like the off brands you get in a supermarket or with Chinese toys, seem to use much harder carbon. A hard carbon will last longer with resistance soldering. Take care when cutting a dry cell battery open because it can be a messy job. Use some sand paper or an old fashioned small plastic pencil sharpener to file a conical tip onto the working end of the carbon rod. 




When I was young, my second cousin taught me how to do this to make arc lamps in flower pots.


----------



## Rudy Allarde (Jan 2, 2008)

Les

I get my carbon electrodes for resistance soldering from MicroMark. They come in 0.078" diameter x 1 1/2" long, in sets of 6 electrodes.










Regards,

Rudy Allarde
Indian Springs, AL


----------



## Rod Fearnley (Jan 2, 2008)

Rudy what is the cost of those please?
Rod


----------



## Rudy Allarde (Jan 2, 2008)

Rod, set of 6 electrodes = $18.95 USD.

Rudy


----------



## Les (Feb 11, 2008)

Rudy,

Thanks for posting the picture. Looks like yours is home-brewed too. I'm going to try to go with the battery cores Carl suggested; MM tacks on shipping fees 'n whatnot. And if I do, the whole thing will've cost me $2. It was an old Sears Battery charger, 10 amp. Even had the resettable automotive circuit breaker, which I'll use. It had a timer motor, I took it apart and obtained some good-looking brass contact strips which I want to try to use for track power pickups. The DC ammeter will go on the control panel. Here's an instance where the Bird of Paradise crapped all over me, it did.








The footswitch I'll make from a long-armed microswitch I've been saving for some years now.

Thanks for taking time to reply.

Les


----------



## Rod Fearnley (Jan 2, 2008)

Thanks Rudy. I have used the carbon rods from batteries in the past too.
Rod


----------



## Dan Pierce (Jan 2, 2008)

What is the voltage and current needed to do this.


----------



## RGSNH (Jan 13, 2008)

do not forget Mcmaster carr Supply, i bought a lifetime supply a while back for very little money.

AL P.


----------



## Dean Whipple (Jan 2, 2008)

I have some info on how to Build a resistance solder tool on the bottom of my web page *Soldering track jumpers....* it is based on a how-to article of a resistance solder tool by _Vance Bass's_....


----------



## Les (Feb 11, 2008)

Dan,

According to the NMRA Bulletin, all you need is a 10 amp transformer. (Those are expensive, new, but as I posted earlier, I got one out of an old battery charger for $2.) The secondary winding is 12 volts, because of the charger. The old mag article I'm referring to used a 6V secondary from an old TV. So, if P=IE, then P= 10a x 6v, or about 60 Watts. The thermal output of a middling-to-smaller soldering iron, in other words. I got a 12v secondary, so P= 10a x 12v, or about 120 Watts, the size of a medium soldering iron.

If you will email me off post, I will *try *to scan the issue and send you the schematic. It's simple as falling off a log, so I'll describe it: You need an AC cord, a foot-operated switch (easy to build from a microswitch and a couple of boards & a spring). This connects to the primary (117v) windings of the transformer. IT IS VITALLY IMPORTANT FOR HEALTH AND ONGOING GOOD FORTUNE THAT YOU USE A POLARIZED PLUG--ONE THAT HAS A FAT BLADE ON ONE SIDE. You must wire the foot switch into the 'Hot/High/Black side of the AC line. If you don't know why, ask and I or others can tell you. But NEVER put a switch on the ground/return leg of an AC circuit unless you have an excellent reason. And then think twice.

Next, you need a fuse for the secondary (12v) side. Since I buy only the best junk, mine had a thermal fuse (instead of blowing, it just opens up for awhile, cools off and closes). It is rated at 12 amps. (Two amps more than the transformer is capable of putting out (without burning up) but that's Sears for you. Their idea appears to be: the fuse will trip before the transformer lets go. Anyway, you can smell a hot transformer, so it's not that bad. It takes awhile for a big transformer to die from moderate overload. Then you need to make a set of holders for the carbon rods. You need to use heavy gauge wire, the article said 8 ga, but I think they're a tad overcautious. I'm going to use 10ga. What it is, you don't want line loss in the leads to the carbon rods. The leads will be 6-8 feet long, probably. You wire one leg of the secondary of the transformer to one side of the fuse, and the other side of the fuse connects to one of the carbon rods. The remaining secondary wire connects directly to the lead of the remaining carbon rod.

Of course, you don't want your hands/body shorting out the 12v, so you need wooden holders. The article said the carbon rods should be made removable, so you can hold one in each hand for difficult-to-reach places. They neglected to mention how nice a pair of wooden handles would be in this case. There are instances of folks with undetected heart conditions that die from small amounts of electricity that many of us (not me) might ignore. I won't mention heat transfer from the rods to your fingertips, as you'll discover that all by yourself. So you want some sort of suitable wooden pincher-type arrangement, spring loaded, though the idea to resistance soldering is, you take your foot off the switch as soon as the solder begins to flow. I haven't tried resistance soldering yet, having learned about it on this board, and decided to try it out. I can torch and iron solder just fine.

Les


----------



## Les (Feb 11, 2008)

Dean,

I went to your site and read Vance's article. I have some issues with it, but I don't want to go into any but the 30A fuse. You want a fuse smaller or equal to the current rating of the transformer secondary--to be fair, it wasn't stated what that current rating was--in order to save the transformer. ALL secondary wiring should be able to carry the current the transformer puts out, plus a bit.

On the upside, he's right about being careful around house AC. I emphasized that in my previous post. Some pixes of his article would help, are any available?

Also, using the dimmer control ahead of the transformer (on the primary side) is a most excellent idea. I believe a standard one will carry the current the primary will draw. I'm debating fusing the primary side on mine, as well as the secondary. (See my post, above).

Thank you for your helpful post, and I in no way mean to criticize or be negative about the contents therein, or inadvertently give offense.

Les


----------



## Dean Whipple (Jan 2, 2008)

Les,
I'm glad you found the web page helpful...other than making up the dimmer switch I didn't do anything with 120v AC....and the battery charger was not modified in any way, just hooked the soldering leads to the charger leads......I really do believe in the KISS (*K*eep *I*t *S*imple *S*tupid) principle.......
I noticed I need update the page as I have used quite a bit and so far I've been more then pleased with the result...


----------



## Les (Feb 11, 2008)

Posted By Dean Whipple on 01/09/2009 5:49 PM
Les,
I'm glad you found the web page helpful...other than making up the dimmer switch I didn't do anything with 120v AC....and the battery charger was not modified in any way, just hooked the soldering leads to the charger leads......I really do believe in the KISS (*K*eep *I*t *S*imple *S*tupid) principle.......
I noticed I need update the page as I have used quite a bit and so far I've been more then pleased with the result... " src="http://www.mylargescale.com/DesktopModules/NTForums/themes/mls/emoticons/smile.gif" align="absMiddle" border="0" /> " src="http://www.mylargescale.com/DesktopModules/NTForums/themes/mls/emoticons/smile.gif" align="absMiddle" border="0" /> " src="http://www.mylargescale.com/DesktopModules/NTForums/themes/mls/emoticons/smile.gif" align="absMiddle" border="0" />









Dean,

I'm an utter failure at the KISS principle. As I said, perhaps in a different post, I have never 'resistance soldered'. I learned of it here. Then I happened to find a schematic and an article in an old NMRA Bulletin. The article didn't indicate rectifiers, which the battery charger has, giving an unfiltered ripple output, probably riding on a DC voltage. I'm guessing, I've never looked at one with a 'scope. Thus, I assumed AC was the way to go, as I know DC arc welding is different from AC; one is better for certain jobs than the other, I'm told, though I once did a lot of AC arcwelding.

I can't think why one would be superior to the other in this instance, perhaps you can explain.

I understand you 'made up' your own dimmer switch? I'm assuming a type of SCR circuit? I'd like to know the details on that. In any case, at first I thought of the old dimmer switches on the floorboard of cars. 

Les


----------



## Dean Whipple (Jan 2, 2008)

Les, 
I have know idea if AC or DC is best for resistance soldering, that's what Vance used so that's what I figured worked best... all I know is that it works great using an *OLD* Battery charger (not one of those fancy new electronic type battery chargers) and I can still use it for charging car batteries....   
As for the dimmer switch again Vance suggested it could be used and seeing as I'm in construction and I had a regular old dimmer switch for a light laying around....I just put it in a metal outlet-box (like you'd use in a house), I also added a foot switch to the extension cord that I made with a micro-switch a spring and a couple of pieces of 1/4" plastic I had laying around......    
Dean


----------



## Dan Pierce (Jan 2, 2008)

12 volts AC at 10 amp. That is about what the Aristocraft Ultima has inside it. Just tie to the transformer and bypass the fan, diodes!!!! 

However, I think the Ultima has a 16 volt AC transformer as its DC output with no load is 22 volts (16 times 1.414 is 22.6). Many claim it was a battery charger, but the voltage output is too high for that. 

So using a battery charger and tapping off the transformer would be a good pick as long as it has a 10 amp capability and had a full wave bridge. 

PS, I have built my own power supplies so i know what to avoid and with a foot switch patched on the input, this should be used with a GFI for safer operation.


----------



## Les (Feb 11, 2008)

Dean & Dan: (Boy, try to keep them straight in your head!)

Well, looks like we've agreed on one thing: none of us knows which is better, DC or AC for resistance soldering. Since I have a spot welder that is AC, and it works just great, I'd have to think it probably doesn't make any difference. When I build mine, which will be AC, I'll learn how to use it and post something.

Thanks for all the good info.

BTW, the GFI might be overkill if one used a 3-prong cord and grounded the case with the green wire. That's assuming the electrician wired in the ground lug on the outlet. (A bunch in my house aren't).

Les


----------



## Dean Whipple (Jan 2, 2008)

The purpose of the dimmer switch is that by lowering the input voltage to the power supply, the output voltage will then be reduced by a proportional amount... 

But I'd be a little cautious using any model railroad power supply power pack with expensive electronics in it.....because, when you are Resistance soldering you are in effect shorting out the power supply to create the heat to melt the solder...._and you might let the smoke out_.....


----------



## Les (Feb 11, 2008)

Yeah, I know about dimmers. What I didn't think was to use one! A perfect--well, great---,well, pretty fair way to control the heat. Back in 72 or so when that NMRA Bulletin was printed, dimmers hadn't been invented, I don' think.

I don't have any Model RR train powerpacks. I have a wall wart that'll give me enough track power, and I'll build one of these small contollers using an SCR with a pot to control speed. That's the plan, anyway.

BTW, those old HO powerpacks are a great source for power transformers, but I bet you knew that.









Les


----------



## Dean Whipple (Jan 2, 2008)

Les,
My comment about the use of model railroad powerpacks was mainly in response to Dan's post suggesting that it might be possible to use a Aristocraft Ultima, I've never bothered to take one apart to see what kind of electronics are in there, but I would imagine like most of the controllers it might not handle a dead short very well......_you know that smoke thing_......


----------



## Les (Feb 11, 2008)

Dean,

Yeah, I was a little slow off the dime, there.









Les


----------



## xo18thfa (Jan 2, 2008)

Hi Les: I found this article some time ago on the internet:

http://1stclass.mylargescale.com/xo18thfa/Building%20a%20Resistance%20Solder%20Machine.doc

Is this the machine you are building? Sure would like to see your results and how it works out.

Bob


----------



## Dan Pierce (Jan 2, 2008)

The Ultima is just a 10 amp transformer feeding a diode bridge and a 10,000 microfarad capacitor. 

There is a 10 amp fuse on the DC side as well as a current meter. 

This unit does not have any fancy electronics inside, no transistors or IC chips!!!. 

So, if you have one of these, you might be able to use it for resistance soldering, sure beats buying something.


----------



## Les (Feb 11, 2008)

Dan,

You betcha! Those resistance soldering units are pretty expensive at MM.

Nobody who's weighed in on this thread knows if AC or DC is better, but for my nickel, the rectifiers are just one more thing to go pffft!

Just curious, was that an expensive power pack when you bought it? That is, compared to the resistance soldering units?

Les


----------



## Dean Whipple (Jan 2, 2008)

Les, I don't know what Ultima sells for now, but when I bought mine 8 or 10 years ago as I remember were $100.00+ and they are just a power supply no controls...


----------



## Les (Feb 11, 2008)

XO,

I just got to look at that file yesterday.

To all who're interested in this thread, if you haven't downloaded it, do so and take a look. I just had a whole, lenghty discourse on what I liked and didn't, hit a pair of hot keys and lost the whole post.

See for yourself. It has some good ideas. (And it didn't have rectifiers).

Les


----------



## Dan Pierce (Jan 2, 2008)

I have had the Ultima since 2000 when I first started. I knew I wanted 10 amps minimum for the future and I had a TE unit to go with it. 

Traded off the old 4 amp original TE and went to the 10 amp unit. 

Now the Ultima is my indoor power as I do not need the high voltage output indoors. 

Cost was $83.00 back then.


----------



## Tom Leaton (Apr 26, 2008)

Ages ago, a modeler began offering these in Model railroader, which reviewed them.  


They were billed as Carbon Electrode Soldering Tweezers, and if I was looking for them on Ebay, that is the phrase that I'd use.


cheers,
TL


----------



## Agra (Jan 15, 2008)

Les, 
have you seen this old thread? 
http://archive.mylargescale.com/forum/topic.asp?TOPIC_ID=38064 

It offers several ideas for the resistance soldering machine. And I'm sure you'd get some answers from Howard about what to look out for etc., he has already done what you want to do. 

André, 
Norway


----------



## Dean Whipple (Jan 2, 2008)

Thanks Andre'
I'd forgot all about that thread......
Here is a clickable link.....
*[url]http://archive.mylargescale.com/forum/topic.asp?TOPIC_ID=38064* [/url]


----------



## Les (Feb 11, 2008)

Dean & Andre,

I'm running a little late in answering.

I picked up from my supply of Neat Junk a printer power cube. Looks like a wall-wart on steroids The output is +10 &-10VAC @ 2amps, or 40 volt-amps. I don't know what that last number is.

If one went across both outputs, one would have 10vac @ 2a, or about 20watts. How long would it last? I don't know. Would it generate enough thermal energy? I dunno. But simple it would be.

Thanks for the link. I'll look at it tomorrow.

I'm actually, finally, after two years, getting a model-building area set up! Go, me.









It was zero deg F here, this morning. That is so wrong, for the St. Louis area.

Les


----------



## Dan Pierce (Jan 2, 2008)

-10 to + 10 gives 20 volts, times 2 amps gives the 40 VA/watts number.

Voltage is too high and current too low for resistance soldering. 

It was mentioned that 12 volts at 10 amps was needed which gives 120 watts/VA


VA is sometimes higher than watts as it has the losses in the transformer included for the power draw on the AC line. 


This is the KISS answer for those that would like to nitpick the real data on watts vs Volt Amps (VA).


----------



## Les (Feb 11, 2008)

Dan,

Well, it was a thought....

Thanks for the hedzup on Watts vs V/A. I don't consider that nitpicking, I consider it solid information, and I'm glad you passed it along.

Les


----------



## Larry T (Jan 2, 2008)

* ...I was just out in the garage and noticed the battery charger sitting in the corner; voila, output is 12DC @ 10 or 2amps selectable...sounds like the answer. Any comments? Thanx...*


----------



## Les (Feb 11, 2008)

Larry,

Just go to the top of this thread and read it thru. You'll find a good discussion on whether to just use the transformer inside the charger(AC) or hook carbon leads to the charger leads (DC). You'll find some good inside dope for saving $$, and good construcion tips so you won't electrocute yourself. So far, no one knows which way is 'best'--if there is any difference.

Les


----------



## Larry T (Jan 2, 2008)

* ...thanx Les, I guess I glossed over the thread...also, Google "resistance soldering station" and you will have all the info you can digest on the subject. *


----------



## Larry T (Jan 2, 2008)

Here is another good read on the subject and a web site for further reference... 

Build a resistance soldering outfitâ€" 

Through the reading of what has been written about resistance soldering and doing additional Google searches, I picked a set of building instructions presented at the 1992 NMRA National Convention by Don Thomas. The write-up can be found at http://www.trainweb.org/bristol-s-gauge/Projects/rsu.html And as usual, I used the advice given by Vance Bass in his write-up on building a Resistance Solderer. 

Disclaimer: By using common electrical practices while doing this project you should be fine, but as with all electrical projects, please exercise appropriate caution. If you are unsure about something, ask a qualified individual to help you! I can not assume any liability for your use of these instructions or the outcome. 

These are the components used: 

Power Supply.â€¦Filament Transformerâ€"I found one on eBay. 6.3v center tap multiple secondary @ 8amps each. $35 

Cabinetâ€¦.Aluminum 4 1/2â€�H x 6â€�W x 8â€�L. Sized to hold whatever specific transformer you get. $25 

Foot Switchâ€¦. Norm-off, momentary on- rated at 5amps $9.68 

4- rubber feet and a handle. $3.79 

2-Binding Posts & Jacksâ€¦.Surface mount, 30amps, & matching plugs. (rated to handle the amperage draw of the transformerâ€™s primary). $8.00 

Hand Pieceâ€¦.Radio Shack 30-watt Soldering Pencil with replaceable tip. $7.69 

Carbon Rodâ€¦. 1/8â€� diameter (Arch Gouging Carbon), usually found at welding shops. $15 per 100 or $ 0.15 ea 

Fuse Holderâ€¦.panel mount, solder terminals, Â¼â€� x 1 1/4â€� 5amp slo-blow automotive fuse. $2.60 

2-Neon indicator Lampsâ€¦.125vac, red to indicate when power cord is plugged in and green when the transformer is switched on by depressing the foot pedal. $5.25 

Household Dimmer Switchâ€¦.20amps-125vac. This switch allows me to vary the voltage to the primary side of the transformer, giving me control of the output of the transformerâ€™s secondary (% of heat range). eBay $3.00 

Primary Power Cord & Foot Switch Wireâ€¦.Stranded, 2-wire 18 ga. 125vac. Form the junk box. 

Hand Piece & Ground Wireâ€¦.Stranded, single wire 12 ga. 4â€™ each of Red (Hand Piece) & Black (Ground) $2.00 

Heavy Duty Clipâ€¦.Black, 30amp.- for ground wire (get the kind with a screw to hold the wire securely). $1.70 

Wow!!! All for about $110 versus the $300 - $450 for the approximately comparable commercial unit. 


To make the hand piece, disassemble the soldering pencil; cut off the 115vac. wire cord, unscrewed the tip from the tip assembly, removed the screw that holds the tip assembly to the main metal barrel, removed the barrel from the handle by drilling out the rivet, then removed & discarded the heating element materials (nichrome wire/mica insulation.) from the tip assembly. Save the tip assembly, the screw, the metal barrel, the handle, and the cord restraint. 



Next, unscrew the tip and discard or set it aside if you have another use for it. Now from the tip assembly cut off the portion where the heating element wire was wrapped. Setup your drill press to drill a 1/8â€� #30 hole lengthwise though the tip assembly. This should just allow the carbon rod to slide through. You may have to replace the original screw since it may be too short to secure the carbon rod from sliding up or down. Use a 4-40 x Â¼â€� screw instead. 

Reassembling the Hand Piece: Cut a piece of carbon rod about 4â€� long and sharpen both ends with a pencil sharpener. Slip the carbon into the tip assembly and replace the set screw. Tighten just enough to hold the carbon rod in place. 


Now strip one end of a 4â€™ piece of #12 stranded wire about Â½â€�, tin it with an appropriate soldering iron. Bend the tinned end of the wire into an L shape, so that itâ€™ll slip up through the handle and into the barrel. Then manipulate the wire out through one of the holes in the side of the barrel. Then with a long nose pliers bend tinned wire back along the barrel body. Now attach a metal clamp around the barrel body & over the wire that is coming out of the barrel, screw it down to achieve a solid mechanical connection. At this point you may decide to reuse the cord restraint or eliminate its use. Reinstall the tip assembly into the barrel. Insert the barrel into the handle and pop-rivet the barrel to the handle using the original holes. Strip the other end of the wire and solder on the connector and insert the body screw to achieve a solid mechanical connection. 


For the ground wire, use another 4â€™ piece of #12 stranded wireâ€¦strip each end and attach the other connector that matches the binding post. On the other end attach the heavy duty clip. Again, be sure to screw down the connectors on each end to get that good mechanical connection. The clip will be used to ground the item being soldered. 
http://pic5.picturetrail.com/VOL92/797386/9529640/135960844.jpg 


For the Foot Pedal: I removed the light weight wire and plug that came with the foot pedal and hooked up the #16/2 cord that will be used for the power. This picture shows the power cord/wall plug and the foot pedal cord. 


Hereâ€™s the transformer: 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202185.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202166.jpg 

The cabinet needs to be of sufficient size to hold the transformer. 
and to provide a surface to mount the 2 binding posts, 2 indicator lights, the dimmer switch and fuse holder. The dimmers faceplate was removed. 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202174.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/136635312.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/137756335.jpg 

Hereâ€™s the front panel layout used and the power and foot pedal wire installed. The hole in the center is to accept the dimmer switch: 
http://pic5.picturetrail.com/VOL92/797386/9529640/136675079.jpg 

Next comes the wiring. 


Add 4 rubber feet at the bottom corners of the cabinet and a handle to the top for convenience. 

I've wanted to build one of these for a long time, so before I do any soldering on my Ruby Bash, Iâ€™ve decided to build a resistance soldering outfitâ€"good excuse, huh? I will be using my mini-butane torch for the larger pieces like the copper domes and the new smokestack but some of the smaller items might lend themselves to resistance soldering. 

Through the reading of what has been written about resistance soldering here on MLS and doing additional Google searches, I picked a set of building instructions presented at the 1992 NMRA National Convention by Don Thomas. The write-up can be found at http://www.trainweb.org/bristol-s-gauge/Projects/rsu.html And as usual, I used the advice given by Vance Bass in his write-up on building a Resistance Solderer. 

Disclaimer: By using common electrical practices while doing this project you should be fine, but as with all electrical projects, please exercise appropriate caution. If you are unsure about something, ask a qualified individual to help you! I can not assume any liability for your use of these instructions or the outcome. 

These are the components I used: 

Power Supply.â€¦Filament Transformerâ€"I found one on eBay. 6.3v center tap multiple secondary @ 8amps each. $35 

Cabinetâ€¦.Aluminum 4 1/2â€�H x 6â€�W x 8â€�L. Sized to hold whatever specific transformer you get. $25 

Foot Switchâ€¦. Norm-off, momentary on- rated at 5amps $9.68 

4- rubber feet and a handle. $3.79 

2-Binding Posts & Jacksâ€¦.Surface mount, 30amps, & matching plugs. (rated to handle the amperage draw of the transformerâ€™s primary). $8.00 

Hand Pieceâ€¦.Radio Shack 30-watt Soldering Pencil with replaceable tip. $7.69 

Carbon Rodâ€¦. 1/8â€� diameter (Arch Gouging Carbon), usually found at welding shops. $15 per 100 or $ 0.15 ea 

Fuse Holderâ€¦.panel mount, solder terminals, Â¼â€� x 1 1/4â€� 5amp slo-blow automotive fuse. $2.60 

2-Neon indicator Lampsâ€¦.125vac, red to indicate when power cord is plugged in and green when the transformer is switched on by depressing the foot pedal. $5.25 

Household Dimmer Switchâ€¦.20amps-125vac. This switch allows me to vary the voltage to the primary side of the transformer, giving me control of the output of the transformerâ€™s secondary (% of heat range). eBay $3.00 

Primary Power Cord & Foot Switch Wireâ€¦.Stranded, 2-wire 18 ga. 125vac. Form the junk box. 

Hand Piece & Ground Wireâ€¦.Stranded, single wire 12 ga. 4â€™ each of Red (Hand Piece) & Black (Ground) $2.00 

Heavy Duty Clipâ€¦.Black, 30amp.- for ground wire (get the kind with a screw to hold the wire securely). $1.70 

Wow!!! All for about $110 versus the $300 - $450 for the approximately comparable commercial unit. 


To make the hand piece, I disassembled the soldering pencil. I cut off the 115vac. wire cord, unscrewed the tip from the tip assembly, removed the screw that holds the tip assembly to the main metal barrel, removed the barrel from the handle by drilling out the rivet, then removed & discarded the heating element materials (nichrome wire/mica insulation.) from the tip assembly. Save the tip assembly, the screw, the metal barrel, the handle, and the cord restraint. 



Next, unscrew the tip and discard or set it aside if you have another use for it. Now from the tip assembly cut off the portion where the heating element wire was wrapped. Setup your drill press to drill a 1/8â€� #30 hole lengthwise though the tip assembly. This should just allow the carbon rod to slide through. You may have to replace the original screw since it may be too short to secure the carbon rod from sliding up or down. Use a 4-40 x Â¼â€� screw instead. 

Reassembling the Hand Piece: Cut a piece of carbon rod about 4â€� long and sharpen both ends with a pencil sharpener. Slip the carbon into the tip assembly and replace the set screw. Tighten just enough to hold the carbon rod in place. 


Now strip one end of a 4â€™ piece of #12 stranded wire about Â½â€�, tin it with an appropriate soldering iron. Bend the tinned end of the wire into an L shape, so that itâ€™ll slip up through the handle and into the barrel. Then manipulate the wire out through one of the holes in the side of the barrel. Then with a long nose pliers bend tinned wire back along the barrel body. Now attach a metal clamp around the barrel body & over the wire that is coming out of the barrel, screw it down to achieve a solid mechanical connection. At this point you may decide to reuse the cord restraint or eliminate its use. Reinstall the tip assembly into the barrel. Insert the barrel into the handle and pop-rivet the barrel to the handle using the original holes. Strip the other end of the wire and solder on the connector and insert the body screw to achieve a solid mechanical connection. 


For the ground wire, use another 4â€™ piece of #12 stranded wireâ€¦strip each end and attach the other connector that matches the binding post. On the other end attach the heavy duty clip. Again, be sure to screw down the connectors on each end to get that good mechanical connection. The clip will be used to ground the item being soldered. 
http://pic5.picturetrail.com/VOL92/797386/9529640/135960844.jpg 


For the Foot Pedal: I removed the light weight wire and plug that came with the foot pedal and hooked up the #16/2 cord that I will be using for the power. This picture shows the power cord/wall plug and the foot pedal cord. 


Hereâ€™s the transformer I got: 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202185.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202166.jpg 

The cabinet needs to be of sufficient size to hold the transformer. 
and to provide a surface to mount the 2 binding posts, 2 indicator lights, the dimmer switch and fuse holder. The dimmers faceplate was removed. 
http://pic5.picturetrail.com/VOL92/797386/9529640/135202174.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/136635312.jpg 
http://pic5.picturetrail.com/VOL92/797386/9529640/137756335.jpg 

Hereâ€™s the front panel layout I used and the power and foot pedal wire installed. The hole in the center is to accept the dimmer switch: 
http://pic5.picturetrail.com/VOL92/797386/9529640/136675079.jpg 



I added 4 rubber feet at the bottom corners of the cabinet and a handle to the top for convenience.


----------



## njp (Dec 6, 2008)

Before you cut up some battery, check the welding supply house. It appears these things often break in shipping and they can't 
sell them. The local shop gave mr a dozen or so broken ones. Other advantages for these rods is with the copper cladding is;
- Solder your feed wires right to the rod for a better connection.
- The copper provides a good conductive path to the tip. Energy is not wasted heating all the crbon from the wire lead to the tip.
- They are smaller to fit into tight spots
- They are stronger and easier to shape or sharpen
- You have an excuse to go to weld shop. You wanted to ask someone who really knows about solder,
look at the neet TIP & MIG welders, etc. Who can pass up a place with really neet tools!


----------



## Les (Feb 11, 2008)

Posted By njp on 01/23/2009 10:35 PM
It appears these things often break in shipping and they can't 
sell them. The local shop gave mr a dozen or so broken ones. 





The only thing I ever get for free is a hard way to go.









Les


----------

