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  • ryanjones2150
    replied
    TC-150, that's it! I have one on my thunderbolt. It's rated output is 150amps and it doesn't have much room for excess. There is. Fusible link inside the machine that will blow. They're cheap, just not readily available. Took my local industrial electrical parts house about two days to get some for me. <br />
    <br />
    I was doing some scratch tig and pushed my thunderbolt to the max...about five minutes of welding and the rectifier just shut off. Sometimes I do dumb stuff.

    Leave a comment:


  • Lostone
    replied
    If your set on trying it this is how I'd do it.

    Use the Bridge Rectifier from a Delco AD244 alternator.
    When I build on board welders I use the them. If you use these ones from the link below you should have more then enough for 150 amps. Plus you can use the back of a AD case for a sink. The bridge mounts right into it and a $2 small personal fan from Walmart blowing through the case will keep it quite cool.

    Your going to also need a toroid core. The capacitor will overheat without it. All the capacitor does is keep the pulsing D.C. from working like AC.

    If if you go with used junkyard parts costs could be even less


    T25XHD Extreme Heavy Duty Bridge Rectifier For Delco & Delphi AD237, AD244 Series Alternators. 210 amp rated.
    Last edited by Lostone; 12-25-2016, 12:18 PM.

    Leave a comment:


  • joel.richeme
    replied
    meltedmetal i sure do not expect miracles from this setup, at least i woukd be able to run 1/8 7018 dcep no problem. for the feeder part i know i would be best served with some CC-CV inverter type machines. the only thing is that i only have 1ph 220v in the shop. im planning on buying one in the next year but i have to wait for a busier time of the year since almost everything is dead here during the winter. it is more an experiment than trying to do something sturdy to weld 60hrs a week with it. could be fun. worst case scenario ill fit the rectifier in my dad's thumbstone 225ac

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  • Meltedmetal
    replied
    I will guess that Miller limits the DC output of the Thunderbolt so as not to kill the transformer. If you pull more output from the system, even if your components are up to the task, the rest of the components may not be.
    Where are you? Maybe someone can put you onto a local deal. Try seachtempest.com for craigslist searches and look at Kijiji if you are in a place listed by them to find an actual Mig machine. You will be much happier. Or do the conversion for the learning experience and have fun. Just don't expect miracles.

    Leave a comment:


  • joel.richeme
    replied
    ryanjones2150 you refer to the tc-150, they are hard to find. according to the manual they only have 4X 85A 300V diodes, one varistor and a stabilizer. im pretty sure if i beef up the components i can get better output.

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  • ryanjones2150
    replied
    Miller makes a DC rectifier for the thunderbolt. Can't think of the model off hand...sc-150 or something. Won't be until Monday before I can get back to the shop and look. But it's still only 150 amps.

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  • xryan
    replied
    You're going to spend as much in parts to.modify the Thunderbolt as a new Thunderbolt AC costs...and still end up with something that will be less useful than a new AC/DC Thunderbolt Just sell the Thunderbolt. You've got other big engine drives and making an execise in futility to use a wire feeder on a Thunderbolt....

    Leave a comment:


  • Aeronca41
    replied
    Originally posted by joel.richeme View Post
    mac702 here are the cost of each option (rectifier part only)
    10x 50A rectifiers 15$
    big 500A 1000v bridge rectifier 56$
    4x 250A 1600v silicon diodes 100$

    connectors 15$
    wiring and terminal 25$
    choke 40$
    2 capacitor 10,000uf 160V 30$.

    on a CC power supply the 12vs is bad at short circuit mig, good with globular transfer and works really well for spray transfer. i just dont know if 200A out of the thunderbolt would be enough for a quality result.

    i made little research but its difficult to find a good CV power supply working on 220 1ph.
    My additional 2 cents worth: the "10 diodes in parallel" in my opinion is a possible but not necessarily good design approach and may not be reliable. Unless you pay big bucks for matched diodes, or buy a big box and match them yourself, each will have a slightly different forward resistance and therefore will not share the load equally. It all depends on the consistency of the diodes you get. The ones with a lower resistance will carry more than their 10% share of the load and will not last as long as the ones that are loafing. Then, you have to disconnect them all and measure individually to find the bad one(s). If you happen to get a couple with very much lower forward resistance than the others, they will fail almost immediately.

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  • H80N
    replied
    Originally posted by joel.richeme View Post
    H80N ill also try to call my local welder repair shop and buy a mig machine with a non working feeder to salvage the power supply part
    good approach....


    The old MM200 has a bulletproof power supply... would be a good candidate

    and is BTW a 270 amp supply...
    Last edited by H80N; 12-24-2016, 05:02 PM.

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  • joel.richeme
    replied
    H80N ill also try to call my local welder repair shop and buy a mig machine with a non working feeder to salvage the power supply part

    Leave a comment:


  • H80N
    replied
    Originally posted by joel.richeme View Post

    i made little research but its difficult to find a good CV power supply working on 220 1ph.
    That is still your best option

    some kind of diy kluge will just waste your money

    Leave a comment:


  • joel.richeme
    replied
    mac702 here are the cost of each option (rectifier part only)
    10x 50A rectifiers 15$
    big 500A 1000v bridge rectifier 56$
    4x 250A 1600v silicon diodes 100$

    connectors 15$
    wiring and terminal 25$
    choke 40$
    2 capacitor 10,000uf 160V 30$.

    on a CC power supply the 12vs is bad at short circuit mig, good with globular transfer and works really well for spray transfer. i just dont know if 200A out of the thunderbolt would be enough for a quality result.

    i made little research but its difficult to find a good CV power supply working on 220 1ph.

    Leave a comment:


  • joel.richeme
    replied
    Originally posted by Lostone View Post
    The loss to heat rectifying to DC will be huge. There a reason that the Thunderbolt AC/DC machine is only rated at 150 amps on the DC side.

    12VS is a CC or CV unit. I've used ours on our 301 at work many times. Your issue is going to be Getting the voltage down. Your looking at adding a big expensive step down transformer to the mix. You'll have more into then it's worth.

    Can it it be done. Probably. Is it going to be effective. Probably not.

    Then in there's still that pesky low duty cycle issue.
    sure the thunderbolt is rated to 150 dc because the rectifier is hooked up to the "low" side of the secondary according to the schematic.

    The XMT or INVERTEC is a good option but i dont have that king of money right now. 1500-2000 is a big investment for me.

    im looking at about 150$ to modify the thunderbolt. low duty cycle isnt a real problem since its more a hobby than an income.

    im just tired of pilling that welder generator outside every time i want to use the feeder, also it cost a fortune tu run the thing all day.

    does anyone have a solution or a suggestion if i want a CV power supply to run the 12vs that will be able to run from 220 1ph ???

    Leave a comment:


  • Lostone
    replied
    The loss to heat rectifying to DC will be huge. There a reason that the Thunderbolt AC/DC machine is only rated at 150 amps on the DC side.

    12VS is a CC or CV unit. I've used ours on our 301 at work many times. Your issue is going to be Getting the voltage down. Your looking at adding a big expensive step down transformer to the mix. You'll have more into then it's worth.

    Can it it be done. Probably. Is it going to be effective. Probably not.

    Then in there's still that pesky low duty cycle issue.

    Leave a comment:


  • MAC702
    replied
    The 12VS is designed to work with a CC (constant current) source. While big diodes can turn an AC machine into a DC machine, I've not actually seen in done since I was a kid. Our first machine was an old Hobart AC machine the size of a big chest freezer. My dad had a box with four big diodes on it for DC stick welding. Worked great, but used exclusively for SMAW.

    Also, feeders operating on voltage-sensing mode for CC use are usually seen on big jobs. I don't know if you'd have the fine control for other jobs that GMAW might be used for.

    Your post asked us to help you choose, but didn't give us any of the actual cost numbers that you are looking at. Just factor in what you think your time is worth, and how much of an experiment you are willing to do versus using the same parts actually used in welding machines.

    Leave a comment:

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