Hello, all...
I'm glad to have found out after my purchase, that this forum is here and has contributions from Everlast representatives.
My Powertig 185 machine came with a torch mounted trigger, so I don't currently have a pedal for my unit. I quickly discovered what a necessity this is, for pulse control on this machine and clean entry and exit on beads. It does rather well on thicker steel without pulsing the on/ off trigger, on cold metal, but after a while, with heat soak it's too much, ramps heat up quickly on the heated part and I have to stop welding.
I was working on my cart/ storage drawer/ mock up table and decided to shift gears to build a pedal.
I saw the youtube video on the modded guitar pedal. I like the idea of a rack and cog gear for linear control over the entire rotation of the pot. I don't like that the throw of the rack doubles the length needed for clearance, so a vertical rack increases the overall pedal height with unused space below, that it needs for clearance. I've seen cog and belt designs that incorporate pull springs that solve this clearance issue, but I'd like to minimize wear parts in the pedal.
I was going to buy a low profile pedal, but I also thought that the rack idea could still be used in a low profile design, as well as consolidating functions and hoses strung across the floor.
So I took the rack idea and changed the design, so it fits horizontally, sliding forward and backward, beneath the cog/ potentiometer. I'm using a 90 degree arm that pivots at the elbow, like a kickdown linkage on an automatic transmission, to allow a vertical link at the toe of the pedal, to transmit to another link that moves horizontally (mostly), connected to the completely horizontal rack.
I wanted to keep the remote trigger, for it's tac capabilities, especially under a car, lying on the ground, doing exhaust mockups or other placing tac welds that require positions.
I've figured out how to incorporate automatically switching from trigger to pedal, without the use of a relay, by engaging a microswitch from the pedal's movement, before engaging the rack linkage. This will be done with a slotted hole somewhere on the linkage, between the rack and the pedal toe, so the motion of the pedal engages the micro switch first. The switch that I bought is a 1P2T type, so it is not on/ off, but rather on/ on. This means that I can run three wires to it, so I can have the hand trigger engaged when the pedal is up and the pedal trigger engaged when it's slightly pressed, before the pedal is on (another micro switch) and the potentiometer moves at all.
I didn't feel like tossing my 15' cable that came with my welder, so instead of upgrading to a 25', I'm going to use the pedal as a junction box, to attach an additional 12' 6" CK Superflex hose. This will give me a total distance of about 28' distance with the pedal, but I figured that 12' will give me enough slack to reach, from the pedal, to any place I could want to reach and a little further, if I'm just out to tac something in mock up, so I can take it off for final welding with a pedal.
The beauty of the 90 degree linkage arm, is that I can have inequal arm length on both ends of the L, so I can change pedal throw to rack throw ratio. Even though I can do this infinately with slotted holes and a locking nut, or multiple holes, I think I'm going to set it to a comfortable foot angle ratio. The rack and cog that I have are stainless and goes through a 2" rack throw, for 335 degrees of cog rotation from stop to stop. I'm going to use threaded rod for the link arms, so I can dial the adjustments in, as not to over or under throw the rack.
Overall sensitivity on amps will be done with a second pot on the side of the pedal. I know I can get the ratio nice with the L linkage, but I actually want to be able to adjust sensitivity on the fly, because I work on a very wide range of metals and thicknesses on a regular basis.
The one downfall to using the CK superflex, is that I lose a little of it's purpose on a torch mount trigger, having a 2 conductor wire running down the whip. So, I decided to purchase a wireless remote that runs a relay. The remote is a momentary on button that transmits a signal to the relay reciever. The range is really far and will work fine for what I want to do. This will also enable me to tac weld using my other hand, if I remove the trigger from the torch, and also allow me to remove the trigger when I'm not using the torch for tac welding, so I don't accidentally tac and for comfort. I will be attaching it with velcro strap.
The set comes with two remotes, so I can keep one in my consumable drawer on the cart, in case the battery goes dead or one is damaged, etc.
I thought about the HF start having a problem with radio transmission frequency, but the frequency of the device is much higher than the HF on the welder. HF is up around 2MHZ and the transmitter is at 340MHZ, so there is no way signal disruption will even come close in bands for the hand/ remote trigger.
Having a 2nd remote also opens the possibility of having an aid help with difficult tacs for positioning, like a header build. I could have one in the trigger or my other hand and call out start/ stop while crawling under a car or something.
So far, I've got the pedal, stainless sheet material for the pedal base, cog gear and rack, potentiometer (bought 50k and 25k ohm, gonna try both out) and the short rubber feet for the entire pedal to sit on. I'm waiting on the CK whip, 7 pin 5/8" connector, wireless remote and 12v receiver relay. I've decided to tackle power to the relay with a 12v battery, either special order or with a 9V and 2 AA 1.5v units.
I could run power to the relay in the pedal for the wireless trigger, from the power lead on the welder.
What gauge of wire is suitable for the 7 leads and what is the voltage signal from 1-2? I can get 12v with a small regulator if need be, although I'm thinking a battery might be the better plan.
I'll post pics of my draft soon and the parts that I have. I'm using a chrome foot gas pedal, for fun.