$10 hand amptrol for Longevity 160sx 200sx machine

[AluminumWelder]

I bought a sliding potentiometer 0-10k Ohms resistance. and attached it perpendicular to the torch handle with some epoxy putty.
I also put some putty on the potentiometer post to give my trigger finger something to pull on.

Then I added some rubber bands to always pull the slide potentiometer to the off position.

I really like the ergonomics of this trigger design better than the east-west (left right) rotary potentiometer that I had on my lincoln PT275 machine.

I searched the board for DIY hand amptrols and there were a couple of threads, but really no final products I could find.
for the electrical connectors shown below:



Just search ebay for 12mm 2 pin or
12mm 3 pin electrical connector and they will show up

They also do not sell a hand amptrol unit for the 160sx, hence invention by necessity.

[forhire]

Do you have a photo of your torch with the setup installed?

[AluminumWelder]

Here are 3 photos
They are all missing the rubber band that pulls the sliding potentionmeter post away from the torch handle and towards the micro switch which keeps the torch off.

When you pull the sliding potentiometer it disengages the "NC" (normally closed) switch to turn the torch on and then you can pull it all the way towards you for full power.

You'll also notice I have a rotary hand amptrol on the torch, My worker likes that one.

I have to train a new worker how to weld and I think this trigger control will be the easiest to learn. 99% of the stuff we weld is 16 gauge aluminum. square tube, so we don't need to hold down the trigger for more than a few seconds at a time.

There are companies that make sliding potentiometers with built in switches, even spring loaded ones, but they tend to be expensive. over $40 and often times special order.

the sliding potentiometer I got from mouser part #
312-9100F-10K
it was a few bucks. I'm sure mouser sells the switch as well, any normally closed switch will work. I like the ones with the lever since it takes less rubber band force to keep it depressed/off. with shipping both of these parts will cost $12 total or less.

for 5 strand wire you can use a USB cable (that's what I used cause I had one haning around from some gadget I never used) it might be a little bit thin though, or thermostat wire which is deffinetely thick enough but not as flexible. Irrigation low voltage wire will also work. Maybe even some ethernet cable?

obviously you would want to solder and cover all the wire connections when done. I had some 5/8" square aluminum tube lying around so I cut off a piece and driled and angle ground it to fit the potentiometer and used epoxy to hold the switch on. ahot glue gun, duck tape, and chewing gum would probably also work, just not look as nice.

Next one I make will stick out another 1.5 inches so I can be lazy and just rest it on the table while I weld. the extra length will also allow the rubber band to flex better over a straight run vs wrapping the band around the bottom.

as far as wiring, if you bust open the longevity cables they are the EXACT same colors for the potentiometer, just hook white to white, red to red and green to green. the black and copper wire controls the switch.

let me know if you have any other questions.