Adapting Vulcan 63895 TIG Pedal to Lincoln 6-pin K-870 and What's Inside!

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Adapting Vulcan 63895 TIG Pedal to Lincoln 6-pin K-870 and What's Inside!

Backstory: I got a Lincoln Idealarc TIG 300/300 at an auction 6? months ago. It powered up and is beautiful inside and out. I'm pretty sure it is US Navy surplus. It did NOT come with the "common" Lincoln 6-pin K870 pedal. The 300/300 has been sitting patiently until I found one. The pedal plugs into the blue connector in front. After fees I paid about $440 for it. Meanwhile, I've sold items bought at that auction for a profit so the welder has become a freebie!

A K-870 pedal from Lincoln is around $400! SSC Controls in Ohio has a near identical unit for around $180. (refer to .pdf for a picture) The word on the street is that SSC supplies pedals for OEMs. I bought a pedal for a Miller Synch 300 from them about 15 years ago so they have been around. But I wasn't in a hurry to pay a chunk of money for a pedal only to find out the 300/300 doesn't weld...

Last week I came across the Vulcan (Harbor Freight) 63895 9-pin TIG pedal in the clearance aisle at my local HF. It was an "open box" return and like-new. Noting it hadn't been marked down in a while, I brought it to the manager's attention and he marked it down an additional 20%. They are supposed to mark down clearance items every 2wks so if you see something that has been sitting a while, don't be afraid to ask the manager for a discount. Anyhow, after tax I paid just about $49 for it. It has a 25' cord on it, BTW. Since it is a clearance item, I only had 5 days to return it.

While there is plenty of info on the K-870, there is/was NONE I could find on the 63895 aside from minor details in the ratings at the HF website. This very well may be the first "review" and disassembly with pinouts available to the public so if you find this info helpful, please click on the yellow "Donate" button above to help support this forum. Note the nearly useless HF diagram from one of their Vulcan TIG welders...

And don't be afraid to buy a SSC pedal as they are US-made quality. If I keep the 300/300 I may invest in their version of the K870. Their schematic/pinout for the K-870 is the .pdf below. The K-870 utilized a 10,000 ohm potentiometer (pot).

So with 5 days to return, I started taking the 63895 apart to see if it could be adapted to the 300/300. Three screws from the bottom showed an access panel to the spring. (continues below)

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With the cover off, I then pushed the spring out of its slot as shown. Using a 10mm wrench and socket, I removed the pivot bolt, spacers and spring. Then I put the pedal back upright. This allowed the top half of the pedal to be removed.

The pedal guts consist of a normally open roller switch that rolls against the top half. The exposed spade terminal would be connected to if the switch were a "normally closed" style.

There is also a rotary pot that has a gear attached and the gear is acted upon by a rack that moves down when the top half pushes against it.

Using a meter, I was able to determine that this was a 10,000 ohm pot so I would be able to adapt it to the 300/300 especially since they utilized the same number of wires. I also determined the pin outs as they relate to the connector. See the chart attached.

Now needing a 6-pin Lincoln-style connector, I checked out Debay and was able to find one for $17 shipped free. I had it in less than a week.

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I cut the 9-pin connector off the 63895 in preparation to solder the K-870 connector in. I left plenty of cord because my goal is to sell it to someone looking to make a hand control or something for their Vulcan TIG. That way the K-870 connector will be "free".

Before soldering, I made sure the K-870 connector was slid down the 63895 cable. I also added a piece of clear tube and some shrink-tube to help stiffen and make more durable the area just outside the connector. This is a common area for wires to be damaged.

Even though the wire colors were the same, three of the five wires between the K-870 and 63895 were in different locations on the pot and switch. I had to de-solder a wire because I realized I had put it on the wrong pin...

Had some trouble with butane devices used to shrink the tubing. The first pencil torch I used caught fire in my hand because of a leak but I was quickly able to turn it off and put it out. Then another one I had wasn't working. Then the small propane torch I used worked OK, but kept leaking at the valve after I removed the torch head. I left it outside to leak out to avoid a fire inside.

Once everything was together, I tested the 300/300 with the 63895 pedal. The welds could have been better once dialed in but I didn't have any 3/32" filler, only 1/16" and 1/8". My scraps were old and dirtyish and I started running out of Argon and didn't feel like digging out another cylinder. I am happy with the results nonetheless (ie: the welder works!).

[toprecycler]

Nice write up. Glad the welder works for you.


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[milomilo]

Good deal all around.

[dleach1407]

I realize that this thread is a few years old. I am looking at using this pedal with my alphatig 201 which uses a 7 pin 10k pot pedal. The AHP pedal is also a 5 wire design with 3 wires for the pot, 2 wires for an NO switch so it appears to be compatible from that perspective. In one of the posts above, it says the Vulcan uses a 10k pot but the written pinout says the measured resistance is 99k. I wanted to verify, should that have said 9.9k? Thanks in advance.

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Originally Posted by dleach1407

I wanted to verify, should that have said 9.9k? Thanks in advance.

I will be honest and say I don't remember but more than likely just a missed decimal point. The welder worked fine but has since been sold along with the pedal so I couldn't check for you. The only reason I used a HF pedal was because I got it cheap. Had I kept the 300/300 I would have invested in an SSC pedal and if you plan on keeping your 201, perhaps you should too.

BTW, Welcome Aboard!

[dleach1407]

Thanks for the reply. To be honest, I like the Vulcan rear pivot vs the more centered style of standard tig pedal. I'm used to using an Eastwood tig with the rear pivot and it's quite comfortable for me. I also have the opportunity to get one for a discounted price and i already have the plug which cost a whole 6$ shipped. Did you not like the Vulcan pedal? I would really like to get your take on it. It seems to get really good reviews. I hate the pedal that i currently have. It's the janky grey one that's works nothing like a standard tig pedal. It's really uncomfortable to use.

[mccutter]

Originally Posted by dleach1407

Did you not like the Vulcan pedal?

I hate the pedal that i currently have. It's the janky grey one that's works nothing like a standard tig pedal. It's really uncomfortable to use.

I don't recall any emotions regarding the pedal, it worked and it was cheap. I only used it for about 5 minutes so not a lot of time to form an opinion. It got the welder running so I could sell it was my goal.

I think I know what ganky pedal you are talking about but you should post a pic here so others will know. They use them with blocks of wood and such to get a better feel...

[dleach1407]

Picture attached