Mod a Welder

Discussion in 'The Projects Forum' started by Dr.killjoy, Oct 22, 2013.

  1. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
    I know this is a long shot but I have Lincoln 3200HD mig welder and I though about modding the circuit with better parts and was wonder if anyone has upgrade there welder or added better parts ????

    Jason Sr

    I was thinking about upgrading the Diodes and adding more capacitance
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    What is the goal? A repair, more power, more durability, more...?

    From my point of view, diodes are diodes. There are not high performance options, just different specs. Diodes are about the cheapest component to over spec so most designs already have diodes that can handle more current than needed.

    Adding more power supply filter capacitors has the downside of blowing fuses if you have too much in-rush current when you turn it on.

    Be careful, lots of time has been put into the design of these things. Changing parts rarely upgrades anything.
    shortbus likes this.
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Like GopherT said, the diodes just convert the AC into DC for the welder output. Changing them will not give more amperage or voltage, the amperage and voltage is a function of the main transformer of the welder.
  4. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
    I broke the 5 k Ohm wire speed pot and it needs to be replaced .. But main point was to enhance the performance of the machine if possible .. I got to thinking last night about the cap and realize that it's a 53 Farad cap and the should be plenty I think ... I was thinking about the Diodes and was wonder if I put higher quality or higher amp ratting would I really gain anything ???? The idea was to upgrade the diodes and maybe increase the duty cycle ?????
  5. MaxHeadRoom


    Jul 18, 2013
    There is nothing to gain by changing the rectifiers, only if you had premature failure etc.
    If they are Lincoln in-house number for a part number, there is very little chance of finding what the originals are.
    Many of the welding manuf. have tended to use International Rectifier, I have found.
  6. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
    My machine has a 20% duty time ( 7mins of cooling to every 2mins of welding in a 10 min period) ... I was thinking that changing to a higher ratting they would run cooler and also increase the heatsink for better duty time ???

    Also the parts numbers

    Someone change their out to these
    M9661-39R- S85JR
    M9661-39 - S85J
  7. strantor

    AAC Fanatic!

    Oct 3, 2010
    the drawing shows 59,000μF, but if yours is actually 53,000μF, that's still not 53Farads. That's .053F.

    If you wanted to add more capacitance, you would probably want to install a soft-charge contactor that charges up the second cap bank thru a resistor until a threashold is reached, at which point the contactor shorts past the resistor and allows it to charge with full available current.

    I'm betting that your most limiting factor is not your diodes or capacitors, but your transformer. Transformer is big hunk of metal with a lot of thermal mass, and probably the reason why you have 7min cool-down time with only 2min run time - time enough to dissipate all that heat out of the big hunk of iron. You might be able to find a higher power transformer at the required voltages, but I doubt it will fit inside the welder.

    EDIT: Also to back up my transformer claim, see top right of drawing; a thermal switch is installed on the secondary of transformer coil.

    EDIT2: perhaps active cooling of the transformer could increase duty cycle. I have seen electronics/electrical cooling schemes that encase the hot part (transformer in this case) in a liquid-tight enclosure and pump mineral oil through the enclosure and out to a radiator, and back into the enclosure, to remove lots of heat fast.
    Last edited: Oct 23, 2013
  8. Rbeckett


    Sep 3, 2010
    As a welder by trade and an inveterate tinkerer by addiction I can tell you that you cannot beef up a 110V AC welder. You are limited by the capacity of the transformer and it's ability to rid itself of heat. You can boost the fan output, and make it come on at a lower temp which will extend the duty cycle beyond 20% but for the time and money you will invest you are better off leaving it alone and saving up for a larger more powerful machine from a factory. Sorry, I love to boost thing as much as the next guy, but Lincoln has stretched it to the max already....

    Gdrumm likes this.
  9. Gdrumm

    Distinguished Member

    Aug 29, 2008
    Hi Tim (The Tool Man),

    Try boosting the wife's dishwasher rinse cycle.

    Reminds me of me!

    I learned a lot from your post. Thanks for posting the topic.