Tig thumb control?

[Munkul]

Lincoln also offer a scroll wheel on their torches, they are steeply priced but I got one to try on our newer Aspect machine because we already had the torch. You'd need a lincoln torch assembly, the drop-in scroll wheel, and then work out which wires go where on your foot pedal plug.

Module to fit LTP torches part no. KP10529-2 - about £90
LTP Torch, WP17/26 roughly same price each, around £240

Alternatively you buy the unit, some 5 core wire and make it work to a standard torch. It will be some fiddling around with resistance/potentiometer values, though!

It's shown here: https://www.lincolnelectric.com/assets/EU/EN/linc-torch-brochure-eng.pdf

 

[Munkul]

Actually the more I think about it, the FIRST thing you need to do is find out what resistance range potentiometer is used in the Jasic foot pedals. This will let you work out what can be adapted to work, and what can not.

The most common ones seem to use 10k ohm pots, but not sure what Jasic are... SSC make a pedal...

 

[Munty Scruntfundle]

There are loads of torches out there with this kind of control, but they're pretty much all machine dependent, all needing different K rated pots for the machine, plus connectors etc. I have no problem wiring something together, which it may come to, but without knowing what's going on it's difficult.

After getting a little fed up with my local supplier who keeps telling me "Just buy a foot pedal" I spoke to Jasic, after much head scratching, manual searching and 3 people arguing, they suggested I buy the specific part that does exactly what I want. "Well", I said, "that might be a good idea eh!".

So, if anyone else stumbles on this thread looking for a torch amp control for a Jasic TIG200PACAD-A, the part number required is TIG38 ERGO-10K. This is the switch only, you pull the torch apart and fit the switch inside the rubber heat shield. This won't solve the other problem of the swivel head, but one thing at a time eh! I am therefore thinking fitting a 10k pot to any torch with the control should work, but I'll see how this works before I start destroying expensive stuff.

There was some disagreement between the technical people I spoke to, one saying it's pointless as it only gives a range of 10 amps, so 100 amps would only ever drop to 90. That makes as much sense to me as making a cat out of sausages. I think the other opinion is correct which is the amps will increase or drop in increments of 10 amps, I'm guessing the board isn't able to read a constantly fluctuating signal in the 10k range (so it's lumped into 1k increments. (a lazy way of doing things.)), and that's where some of the cash goes when buying a more expensive machine. This begs another interesting point to be made, it means that this is all the foot pedal can achieve too. However, given the confusion the manufacturers left me with, anything is possible!

Once it's here and fitted I'll report back on its usability.
Thanks for all the advice, in the end it pointed me in the right direction. )

 

[Dcal]

They need a 10K pot
They also have a separate plug for the switch and foot pedal.

For the foot pedal you need both plugs (or I think you do) so its a good place to start.
Don't know about the adjustment range as I haven't finished rigging my lash-up yet. (Roland electric piano foot pedal)
I need to rig a box to convert the 5 pin plug I put on the pedal to be used on my bead roller, to 2 plugs to suit the Jasic.
I have all the stuff I just need the time and inclination.

Cheapest place to get the plugs I found was Jasic

I haven't really needed a pedal (mostly weld mild steel) and there's always something else to do, but it's about time I sorted this out

Have you a link to where you can get the TIG38 ERGO-10K?

 

[Wallace]

My first thought, use your trigger finger to operate a lever or trigger operated cable to a modified pedal then I thought pistol grip and Googled "pistol grip tig torch".........CK Steady Grip

I would quite like one myself!

 

[b4lamb]

Have you looked at either the TigButton or Touch4 finger or thumb control these work by pressure applied to the button on the torch much better than wheels or sliders. The TigButton is my preference as its completely analog and smooth current control just like a foot pedal.

 

[b4lamb]

The advantages of TigButton over the CK Steady Grip is that it will directly replace your existing torch button and is transferable between torches if you have more than one. The steady grip is very bulky so you will quickly find jobs where you can't get it in to perform a weld.

 

[mtt.tr]

i would think a force sensing resistor with a potentiometer would give you what you want , though they are not very linear so would really need something like an arduino to help with that. also need some code in the arduino to start the arc use the arduino as a 0=5v output or what ever your machine works on

i might give it a go for you see if i can get the bits

 

[jrwhalley]

I think this was the original thread discussing the pressure sensitive resistor control on welding web
https://weldingweb.com/archive/index.php/t-79951.html.
IIRC he posted shots of the prototype control and build details on one of the follow-up threads. I was wondering about adapting a strain gauge electronic scale to do similar at the time.

 

[fzr phil]

Personally i despise talking to robots, but if in your situation that might be different.
How about voice activated?
Might be an interesting project for a student or someone with the time.
"More".... turns it up
"Less" .....turns it down

Good luck
Phil

 

[anto44]

Personally i despise talking to robots, but if in your situation that might be different.
How about voice activated?
Might be an interesting project for a student or someone with the time.
"More".... turns it up
"Less" .....turns it down

Good luck
Phil

And if you say b******s it knows you dipped the tungsten again and switches off.

 

[chris pruteanu]

The Amp control button from a thermal arc tig torch or parweld tig torch will work in a few different makes of torches all sharing the same ergo design. I have used the amp control on the thermal arc ta202 acdc standard torch and i found it cumbersome- easy to misadjust with gloves on when quickly pulsing the switch ! I do not use a foot pedal- i have it but it sits under the welder but- my torch button is used on welding all kind of metals from copper to alluminium and all steels as well ! You dont really need a pedal to weld woth- with experience you kinda get to know what settings work and running a bit hot/cold isnt a problem as you can adjust travel speed to match melting point of the parent material...

 

[b4lamb]

i would think a force sensing resistor with a potentiometer would give you what you want , though they are not very linear so would really need something like an arduino to help with that. also need some code in the arduino to start the arc use the arduino as a 0=5v output or what ever your machine works on

i might give it a go for you see if i can get the bits

Yes I used a FSR and linearised using a small PIC at the torch end but sent serial digital data back to the Tig set via a small screened pair cable run inside my torch cable zipper cover. I decode at the tig set end (using another PIC) and provide the hf start contact and linear 0 to XV drive to replicate the foot pedal pot input.
My design measures the foot pedal pot voltage and self limits the voltage range to prevent over driving. In my case X is 10.2V. I went digital to prevent any RF and electromagnetic pickup issues in the cables, particularly in AC and pulse modes and at high current settings and HF start. It works brilliantly with very smooth current control with my Murex ac220i same as a ESAB Caddy 7200 I believe. Although these tig sets are CAN bus interface I have modified the foot pedal to run either as it was designed or with a slide switch to take signals from my FSR torch controller. There is sufficient current available on the 12V CAN interface supply to run my electronics.
I'm going to test out on a mates TIG set that has the conventional analog pot and switch interface to the food pedal, I'm confident it will work fine but may need a separate power adapter if the pot supply current is insufficient.

 

[b4lamb]

I think this was the original thread discussing the pressure sensitive resistor control on welding web
https://weldingweb.com/archive/index.php/t-79951.html.
IIRC he posted shots of the prototype control and build details on one of the follow-up threads. I was wondering about adapting a strain gauge electronic scale to do similar at the time.

Thanks jrwhalley, I read (well quickly scanned) that long thread this afternoon. It's goes on a bit doesn't it? It's funny reading ideas from non electronic engineers evolving an ugly solution by committee. I was enlightened to read that control of current from use of a pressure sensitive resistor is patented since, as stated by the member, it's a bleeding obvious application for such a sensor! I'm surprised it was accepted as a patent! In any case a strain gauge button sensor could equally be employed to do the same job albeit needing a few more front end electronic components to amplify the small signal output from the strain gauge bridge but this is not rocket science and used in millions of applications. Indeed the use of a button strain gauge was my initial choice but flipped to a Force Sensitive Resistor as linearity and exact repeatability is not actually that critical in this application. Component cost as well was also factor for me. In addition to this, the TIG welding set actually converts input voltage to current control so the TIG torch finger controllor is converting force to a voltage and not current.

 

[Ruffian]

Ck now also do a slider control on the tig torches for where a pedal is not applicable.

 

[b4lamb]

How is the arc started and stopped on this design. The video doesn't make clear.