Foot Pedal Control

  1. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    I finally upgraded my little DC Inverter Fusion 200PHF TIG to a decent (for my budget) AC/DC welder, a Parweld XTT202P and began hooking it up yesterday.
    I've got a foot pedal with it and when I plugged it in, the settings I could alter became extremely limited and controlled completely by the Pedal.
    So starting amps was 5amps and full pedal deflection would get me to around 200Amps, but with the pedal connected I cannot change them.
    There is a loop in the foot pedal plug connecting pins 1 & 2 which I think cause this effect but is it "Normal"
    I have a pedal on the IFL 200PHF and I can set the start amps and peak amps and modulate in between on the pedal, I know the start amps on the XTT202P are set automatically unless you set 4T.
    I have a Parweld torch with the trigger and amperage control wheel which I am going to connect up omitting the Pin 1 & 2 loop and see what that does.

    My question is which is the "Normal" way for the Welder / Pedal combination to work?
     
  2. AndersK Member

    Messages:
    572
    Location:
    Sweden
    The pedal disables the start amp setting on the parweld, pedal controlled only. Actually it disables all current control from the panel.

    With an extra pot on the pedal you can limit max amps at full stroke.

    I think someone here posted a diagram of how to connect a third pot to enable start amp settings too.
     
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  3. TigTigger Forum Supporter

    Messages:
    57
    Location:
    UK South Gloucestershire
    Does anyone know if the same or similar applies to the Stealth Dgi Tig 200 ac/dc when using a pedal? The manual is useless!
     
  4. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    I found a couple of good threads on this:
    https://www.mig-welding.co.uk/forum/threads/parweld-xtt-202.84920/
    https://www.mig-welding.co.uk/forum/threads/parweld-foot-pedal.61040/
    If I had seen them before I might have had second thoughts about the Parweld XTT202P and I almost bought the Thermal Arc 202 AC/DC and wondered, as they look similar, if it operated in the same way, disabling the panel when a foot pedal is connected.
    The Thermal Arc manual is much better and it even sais this:

    "When the 202AC/DC is used with a Remote Foot Control, disconnect the foot control to allow max
    current to be previewed / adjusted, then re connect foot control, max current that has been pre set
    will be output when foot control is fully depressed during welding. The maximum current can also
    be adjusted in welding operation when foot control is fully depressed. To avoid premature arcing,
    please ensure the TIG Torch is located away from your work piece.
    "

    Anybody know if this is how the Parweld works too?

    I spoke to Parweld about disconnecting the looped pins, but they said it wouldnt make any difference, but that I could use the side pot to limit the current if I had a Parweld foot pedal. I do, but it was removed by the previous owner, so I am about to reinstate it and see how I get on.
    I wondered if there was any merit in mounting it seperately to the foot pedal, on a fly lead up on the bench and then maybe adjusting on the fly?
    Maybe that is trying to make a "Sow's ear" out of a "Silk purse"?
     
  5. Bladevane

    Bladevane Member

    Messages:
    469
    Location:
    Harwell, Oxon
    I use the Parweld pedal with the XTT202P and really don’t find a problem with adjusting the maximum current with the potentiometer on the pedal. The time it takes to set the current provides a gas purge so I know the torch is fully primed. Do you need to know potentiometer details if you are going to reinstate?
     
  6. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    Thanks Bladevane, I will probably get used to it, so are you adjusting the amperage before welding or adjusting it depending what the puddle is doing as you go?

    I was using it today with a Parweld torch with amperage control and it was fine (The pedal is dismantled awaiting the pot) Its just when you change over I guess and I was a bit surprised that it was so different from my others. I work on thin stuff quite a bit and on my first trial welds I was a bit heavy footed, so I thought increasing the resloution might be an advantage.

    I have some details on the POTs wiring but it would be great to check against what you have, so yes please. I read in a post that there is a 20k and a 50K pot, the 20K is on the foot control so I'm guessing its the 50K that is missing, be very helpful if you can confirm that for me.

    Appreciate the help.
     
  7. Bladevane

    Bladevane Member

    Messages:
    469
    Location:
    Harwell, Oxon
    My modus operand is to stamp on the foot pedal and set the maximum current on the pedal potentiometer. I believe the advantage is that you have full pedal movement over the set current range rather than full pedal movement over the maximum the machine is able to deliver. This would be an advantage when welding thinner material. The minimum when the pedal is connected is always 5 amps.

    Here is a picture of the actual side potentiometer. The brand looks like COSMOS, Tokyo. RV24YN 20S B203 157C. I did a quick search for it and they have a datasheet which I interpret as being logarithmic 20k. Here's the link https://lcsc.com/product-detail/Potentiometers-Variable-Resistors_20KR_C128186.html

    I couldn't see what the text was on the pot. driven by the pedal rack. Let me know if you want that detail and I'll see if I can dismantle it to find the data.

    IMG_1234.JPG
     
  8. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    That sounds like where I am trying to get to.

    AndersK wrote in that post "Looking at the markings the foot pot says B503 and the other B203", but on mine the foot control is the B203 so 20K so I wonder if they are both B203's or if mine got swopped at some stage.
    What is weird though is my B203 foot control pot has the longer thread but the same markings as yours.
    IMG_3854.jpg IMG_3856.jpg

    I wouldnt want you to go to the trouble of dismantling yours to find out though, but if anyone else knows or even if it actually matters it would be good to know.

    I've got both the B503 and the B203 coming so options covered. I will probably fit the B203 first.
    Thanks for the info Bladevane.
     
  9. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
  10. Bladevane

    Bladevane Member

    Messages:
    469
    Location:
    Harwell, Oxon
    Just checked the pot. under the pedal and it’s RV24YN 20S B503. Sounds like the previous owner swapped over the pots.
     
  11. AndersK Member

    Messages:
    572
    Location:
    Sweden
    I've fiddled with the dip switch on my XTI202, to disable DC start in AC mode, but that one only have 3 switches. The XTT might be different but from what I heard from another member here, who sell them, its only cosmetic differences between xti and xtt.

    Take out the 4 screws holding the front panel and you can access behind and see if there's more than 3 switches.
     
  12. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    Bladevane - Thanks for checking, that's a life saver, I was just about to fit a second 20K so now I will swap them both out.

    AndersK thanks for that info and all the previous posts that have helped me a lot.

    I will update with where I get to.
     
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  13. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    So my foot pedal now has the correct B503 on the pedal, the original B203 on the current adjuster and wired as per AndersK sketch. And it works!!
    IMG_3857.jpg IMG_3858.jpg IMG_3859.jpg
    Setting the current control to max gives 10amps at idle and 200amps at full throttle (pedal).
    I can select anything from 10amps to 200amps and the pedal maxes out at that setting, controlled by the pedal current adjuster.

    Now it gets interesting. I followed AndersK's suggestion and removed the 5 screws of the display panel.
    IMG_3860.jpg IMG_3861.jpg
    The dip switch module is easy to see and easy enough to get to with a long small screwdriver. I turned dip switch 5 off as posted by Dalzani Lima with the same results. Base current is now 5 amps not 10 and you can set any amperage desired and the pedal maxes at that amperage.

    The only consequence is that 4T doesnt seem to be available anymore.

    All I have to do now is make my mind up about how I want the thing to work, I actually quite like the adjuster on the side of the pedal, now that I've got one and it is actually working.

    Thank you Bladevane for taking your pedal apart to check the POTs for me and explaining its correct operation, thanks to AndersK for the wiring diagram and accessing the dip switch and thanks to Dalzani Lima for posting about the Balmer Maxxi Tig which must be a clone.
     
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  14. AndersK Member

    Messages:
    572
    Location:
    Sweden
    Since I obviously can't count to 5 :rolleyes: I opened mine up but I only got one 3-pole dip switch. :(

    So there seems to be more than just cosmetic differences between the xti and the xtt then.
     
  15. Richard.

    Richard. Member

    Messages:
    17,949
    Location:
    Cambridgeshire
    4T isn’t available on any machine I know of when a pedal is connected because it’s not usable. Same as your up/down slopes. A pedal offers you full control over the whole current range on the fly so there is no need to have start and end currents or slopes etc available to you
     
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  16. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    Thanks richard, that makes a lot of sense, I will try disconnecting the pedal and see if I can select 4T, not that I've got to a level yet where I need it, I can MIG ok but need to practice a lot more with TIG, but I am curious if for the sake of throwing a dip switch and making the pedal simpler and the XTT202P more like other welders what is the advantage of doing it that way?
    There are a lot of posts with people put off or dissapointed by this "feature".
    I have put mine back to as supplied and for the moment I'm happy to set it at the pedal for the time being but triggering to set the amps cant be as safe or sensible as pressing a button on the display and setting it, can it?
     
  17. Bladevane

    Bladevane Member

    Messages:
    469
    Location:
    Harwell, Oxon
    Well done. Pleased you got it back to a working original spec.
     
  18. TR6 Rebuild Member

    Messages:
    21
    Surrey, UK
    Hi AndersK, I hope you didnt think I was being funny! :ashamed::doh:thanks to your advice it was much easier to take the display out than the way I would have tried. What I was trying to say was it was such an easy and quick fix - 4 (5) screws and a DIP switch to change the XTT202P to a conventional format.
    The Balmer Maxxi TIG 200P, The Thermal Arc 202 and the Parweld XTT 202P all look like the "same" machine, but the Parweld manual is inferior to Thermal Arc's and even though it was in Portugese I managed to get the information on the DIP switch from the Balmer manual.
    I wonder how many other clones are out there?
     
  19. AndersK Member

    Messages:
    572
    Location:
    Sweden
    No worries mate, just being ironic at my own expence :D

    Don't know if that translates well, I better shut up now :cool:

    Happy you solved the problem, this is a great forum :thumbup:
     
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