Results 1 to 12 of 12

Thread: Lincoln precision tig 275 foot pedal not reducing amperage

  1. #1
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Lincoln precision tig 275 foot pedal not reducing amperage

    So I recently had my welder serviced for HF not working correctly on the AC side, installed were new contact points for a spark gap of .015 at the local welder repair shop. Machine now fires up like it should while welding aluminum but there are still some issues.

    My foot pedal K870 seems to not reduce the amperage after firing up on mild steel tubing 11.ga. When it fires up it feels like it only has one setting and when I try to increase thereís no increase and on the decrease side there is no decrease in amperage.
    a new foot pedal is $600-700 USD. A new potentiometer for the pedal is $200-250.
    Iím thinking of returning it to repair shop to try and fix this issue, Iíve already tried checking the POT with a volt meter and it seems to work fine on both terminals to include ground.
    So my question is could it potentially be the control board which is $1500 and could it be replaced DIY, like a plug in play type deal.

    while welding 2x2x11ga.steel square tube and where the radius meets the the welding joint Iím getting fisheye type porosity in my tacks and Iím thinking it could be related to amperage. It kind of feels like suck back when pipe welding.

    any input will be appreciated

  2. #2
    Join Date
    Dec 2014
    Location
    Alva, Ok
    Posts
    19
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Double check your minimum output setting that it's not set to high. I have a 375 that is new to me and posted about some issues https://weldingweb.com/vbb/threads/7...ld-in-TIG-Mode see reply #11 you may find it helpful. Also, if you decide to try a new amptrol I see a new Lincoln on ebay for $300 https://www.ebay.com/itm/11532313375...YAAOSwm-9iRz4- I hope something here helps. Kirk T

  3. #3
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Did Franco ever send you a repair price .. ?
    For now I just need to know if a person can order a control board and replace it on their own ..maybe DIY.
    Otherwise Iíll just take it to repair shop.

    Yea I did check the POT and it did have a low side and a high side reading like it was supposed to ..
    Iím just not getting variable amperage when pedaling down or up ..

  4. #4
    Join Date
    Dec 2014
    Location
    Alva, Ok
    Posts
    19
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    You can order it and replace it on your own. No warranty through Lincoln unless a Lincoln authorized repair center installs it, 1yr. if installed by Lincon auth service center. Franco's price was $500 plus parts and shipping and a few other small charges.

  5. #5
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Ok, thanks!
    So back to researching this, I'm thinking of replacing the control panel. Apparently my machine is one of the 1st models from 1980s. The gentleman I bought this from, had a plastic mold outfit where he had to do micro welds on tooling type work and his son apparently used it a lot so I'm beginning to think he probably did something to it. Never the less when I got it I knew I would have to address something or other.
    I'm wondering if I upgrade to the advanced panel would I have to get a control board to accept the advanced panel? or does ordering the advanced panel come with its own a control board? and it would be worth just upgrading to just that. Enclosed is a pic of what I'm talking about. I think they just added a pic of that to illustrate the "ACP".

    How do I get a hold of Franco? I assume he can fix my control board maybe or check to see what's wrong with mine to see if it's faulty?
    Also may I ask what type of torch do you have, maybe I should change out the torch, maybe rule that out before I go diving into it deeper. I have the Weldcraft WP-20 and thinking of the flex head water cooled from CK.

    I thank you for your help

    Name:  advanced control panel .jpg
Views: 77
Size:  34.9 KB

  6. #6
    Join Date
    Dec 2014
    Location
    Alva, Ok
    Posts
    19
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Quote Originally Posted by US.Fabricator View Post
    Ok, How do I get a hold of Franco? I assume he can fix my control board maybe or check to see what's wrong with mine to see if it's faulty?
    Also may I ask what type of torch do you have, maybe I should change out the torch, maybe rule that out before I go diving into it deeper. I have the Weldcraft WP-20 and thinking of the flex head water cooled from CK.

    I thank you for your help
    If you don't have the correct manual for your machine, I would strongly suggest going to Lincon's web site and downloading the correct manual for your code number. I have spent a lot of time in my manual and resolved all issues other than my cable being burnt up. If you currently have the advanced panel, make sure you are not in 4 step mode while using the amtrol it says in the manual it will make the machine do strange things. The following is from the manual.

    • DO NOT USE 4-STEP IF USING AN AMPTROL REMOTE. • Neither the arc start switch nor the output control in the amptrol will function normally to shut off or control the output. ONLY USE 2-STEP. When using an Amptrol remote control, where the downslope is controlled by the operator down to the crater-fill level, the Downslope time should be set to zero so as not to have the Downslope time delay when the arc start switch is opened.

    I replaced my Tig torch with exactly what came with the machine because it suited my needs well and I wanted to stay Lincoln, I just don't know the other brands and what's good and what's junk. This is what I replaced mine with, PTW-20 250 amp water cooled TIG torch w/ 25 ft. cable part number K1784-4.

    When Franco messaged me, he furnished the following web site for contact frankcoproducts.com
    Last edited by Kirk T; 3 Weeks Ago at 09:49 AM.

  7. #7
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Yes , thank you.. I do have the correct manual, I guess I better check the DIP switches to make sure they set correctly and not on 4t.
    yes I’m also thinking of getting the original PTW 20-250 to keep machine original.

    thanks for your help

  8. #8
    Join Date
    Dec 2014
    Location
    Alva, Ok
    Posts
    19
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    The settings I am referring to are not dip switch settings. They are toggle switch #12 (2 step/4 step) and knob #17 (Downslope)
    Attached Images Attached Images  

  9. #9
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Oh for sure, I’m tracking. I don’t even have the advanced panel installed at the moment and I did reach out to Franco products. To me seems like a good deal to refurbish a board but I no longer have to go that route.
    I went ahead and removed the front panel to expose the control board and there it was! There was a wire disconnected, i connected it back and everything seems to work as it should now on to the next issue.

    It seems I’m getting fish eye or craters ( it’s really like porosity) when I tack material together. So I ordered a new torch and lines to replace the one the privet owner had hooked up when I bought the machine. I’ll start there and access the gas solenoid and inspect the lines going to the fittings.
    I appreciate your help.
    thanks

  10. Likes Kirk T liked this post
  11. #10
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Ok , here is the update after the new CK 300 amp WC torch came in. Swapped it out , fired up on some what looks like some 11ga sheet metal slugs from the armada punch machine (un-cleaned) still had a little bur and probably a bit oily. Weld came out a little cold using some EWG E3 with a brown haze like it was just cut with plasma but the weld might of been ok at best. The tacks came out alright but they just tacks.

    Went to the welding store and picked up some red tipped thoriated 1/16 and there was a big difference after cleaning the material with acetone, tacks came out way better and the welds even better, there might of been some fish eye that I could have improved on my technique a bit but itís definitely heading in the right direction.

    on the AL side of things I used the green tip on some fresh AL and experimented with stick out and the results good and bad, thereís definitely an improvement and definitely heading in the right direction.
    so I ordered some white tip .8% zerconiated to see if I can improve beyond the green tip tungsten.

    what I found out is this, the Precision TIG being an old school type transformer machine requires specific type of tungsten to work correctly. Red green and potentially brown and white. Tungsten prep would be pointed for steel and not pointed (balled) for AL. The point will eventually break off when carrying a lot of heat/amps thus up-sizing the diameter of the tungsten.

    in reference to the brown and white tip tungsten , more to follow.. here ar the pics
    Name:  4A668641-B09D-4961-9F49-7E5917323794.jpg
Views: 42
Size:  200.3 KB
    Name:  B8DC38B7-477D-4FAC-B27D-D44DAC15B33B.jpg
Views: 42
Size:  102.8 KB

  12. #11
    Join Date
    Dec 2020
    Posts
    7
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Ok, I'm learning that the pre-flow needs to be running by hitting the pedal and run post-flow, once that's done and running I can tack proper. For welding the white tip zirconated tungsten is the way to go for this machine. Now I just need the larger diameters.
    Enclosed pic is using the 1/16th dia. white tip. For technique I'm soaking the material too much with heat. No wire brush , just wipe with acetone.
    Thank you all for your time.

    Name:  al welding white tip.jpg
Views: 27
Size:  165.8 KB

  13. #12
    Join Date
    Oct 2014
    Posts
    1,558
    Post Thanks / Like

    Re: Lincoln precision tig 275 foot pedal not reducing amperage

    Quote Originally Posted by US.Fabricator View Post
    Ok, I'm learning that the pre-flow needs to be running by hitting the pedal and run post-flow, once that's done and running I can tack proper. For welding the white tip zirconated tungsten is the way to go for this machine. Now I just need the larger diameters.
    Enclosed pic is using the 1/16th dia. white tip. For technique I'm soaking the material too much with heat. No wire brush , just wipe with acetone.
    Thank you all for your time.
    The pre flow and post flow settings should force you to use them. The preflow counts down before you get fire then fire goes out while post flow keeps
    gas flowing, just keep the torch in place until it finishes.
    Last edited by danielplace; 1 Week Ago at 11:22 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Page generated in 1,660,752,426.06944 seconds with 15 queries