The Chicago Electric TIG welder available from Harbor Freight for $499 (on sale) is a fairly basic TIG welder. It does have a High Frequency start, which is controlled by the rocker switch on the TIG torch. I discovered using it that it’s very difficult to keep the torch lit while pushing the button. My hand was just in an awkward position.
Another drawback with this welder is the lack of “on the fly” heat adjustments. I would have to start the weld, then pause to adjust the amperage. This left less than desirable start/stops in the welds. That & trying to manipulate the bulky torch & filler was next to impossible for me to do accurately.
So to solve the problem I was determined to add a foot pedal to the welder. This is the story.
I purchased this welder from a fellow member of one of the forums I frequent. In our communications he let me know about a modification that could be done which adds a foot pedal. I followed that thread & tried to contact the original poster, but that was in vain. Half-heartedly I decided to attempt to do this myself.
In that thread, there were links to some foot pedals on ebay that cost upwards of $300-700.00. I didn’t pay full price for the welder, why would I want to pay full price on the foot pedal. I was going to make one, but didn’t feel my fabrication skills would be good enough (the electrical part that is) to make it work. Further searching & I found a foot pedal listed for $69.99. Including shipping it was at my door in a week for the measly sum of $84.90.
The foot pedal case is substantial. It’s made out of 14 gauge metal, has a heavy spring & a sliding pot. The hook up is a standard 7 pin & there is a micro-switch inside as well. Perfect for my needs.
I needed a 7 pin bulkhead connector to connect the foot pedal to the welder, which I also found on E-bay. Cost more in shipping than it did on the connector. I think it totaled around $8-10. Then one last item, a 3PDT toggle switch. Not to be had locally, had to order it. Guess what I had that little gem in 2 weeks all the way from Shanghi. $12 was the total cost including the shipping. Not too bad considering I looked at Granger & they wanted close to $150.00, McMaster the same. Found one on Amazon for total of $42.00, but after it was ordered the company canceled the order due to not having any in stock.
Well, I had my parts. A 7 pin foot pedal from Excel (E-Bay), a 7 pin bulkhead CB/Nam radio connector, a 3PDT toggle switch from China. I also downloaded the owners manual from Harbor Freight. It has a wiring diagram inside it that was very helpful.
First thing I did was open the case. Pretty clean inside to be honest. Lots of wires & connectors. I looked at the wiring diagram & found the connector that controls the panel potentiometer. Pulled that pot out & discovered it was a 5K pot. Had 3 wires connected, Green, Black & Blue. I used my ohm meter to determine which wire was the wiper (center one) & could then calculate where I needed to put the toggle switch.
I mounted the toggle switch in the center above the front louvers, as there was nothing behind that location. Using the wiring diagram I cut & connected the circuit board connector to the middle lugs of the switch. I connected the top lugs to the foot pedal panel connector wired the same as the foot pedal. The panel pot connected back to the bottom lugs. Now I can use either the panel pot or the foot pedal. Don’t even have to disconnect the foot pedal.
The welder already had circuits to control the output. Switching to the TIG mode activated the High Frequency start. In Stick mode the HF start circuit is not activated.
Now remember I had a micro-switch in the foot pedal? Well it got connected in place of the torch switch. Right into that 7 pin CB/Ham radio connector. That connector required soldered connections, so I used some 22 gauge wire to match the colors of the foot pedal.
The connector also followed foot pedal colors from the potentiometer to the toggle switch. The colors changed at the switch to keep all of it straight in my mind (I’m kind of dense sometimes).
Once I had the 7 pin panel connector wired, I connected the foot pedal to the connector, toggled the switch to the foot pedal & hesitantly added power. Using the foot pedal I could not get the amperage to change. I soon discovered I had a 1K pot (not the 10K pot that was advertised) in the foot pedal. Back to the internet, found a 5K pot (to match the panel pot built into the welder) & got it ordered. A week later I had it. Pulled apart the foot pedal, removed the 1K pot, soldered in the 5K pot & got it adjusted so I have full travel. This pot is a sliding pot, not rotary so it’s fairly simple to add.
Pic 1 - Inside the welder, rather clean if you ask me,
Pic 2 - The foot pedal in question,
Pic 3 - Foot pedal connector,
Pic 4 - The 7 pin bulkhead connector,
Pic 5 - Inside the foot pedal.
More to this story...........