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Thread: What did you machine today?

  1. #1561
    Join Date
    Nov 2006
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    durban s africa
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    1,527

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    Quote Originally Posted by ezduzit View Post
    R--thanks. That went on a 65' aluminum boat named Maiden Factor.

    https://www.themaidenfactor.org/
    Nice How did you do the slot.

  2. #1562
    Join Date
    Jun 2013
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    marina del rey
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    256

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    Quote Originally Posted by plunger View Post
    Nice How did you do the slot.
    Used a 1/4" 2-flute end mill for the slot.
    12" x 35" Logan 2557V lathe
    Index "Super 55" mill
    18" Vectrax vertical bandsaw
    7" x 10" Vectrax mitering bandsaw
    24" State disc sander

  3. #1563
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
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    3,674

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    Actually machined instead of just fooling around and making a mess. Spring loaded hand-held spot welding electrode "holder" for spot welding battery tabs





    Copper, polycarbonate and black polyethylene

  4. #1564

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    Quote Originally Posted by MattiJ View Post
    Actually machined instead of just fooling around and making a mess. Spring loaded hand-held spot welding electrode "holder" for spot welding battery tabs


    Copper, polycarbonate and black polyethylene
    More pics! Looking interesting, how is it powered? How does it work?

  5. #1565
    Join Date
    Dec 2016
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    Helsinki, Finland, Europe
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    Quote Originally Posted by Tungsten dipper View Post
    More pics! Looking interesting, how is it powered? How does it work?
    Powered by large electrolytic capacitor bank charged with adjustable DC (lab) power supply.
    12x 68mF 35v caps in parallel, controlled with beefy parallel pack of mosfets. Results in short current pulse of few thousand amps that takes care of the spot weld.

    This shows somewhat similar unit in operation
    https://www.youtube.com/watch?v=6DbKR4-FMDA

    Waiting to get 100% nickel strips from china, current ones are nickel plated steel and make lots of sparks when welding..

  6. #1566
    Join Date
    Oct 2012
    Location
    San Antonio TX, USA
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    2,832

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    Quote Originally Posted by MattiJ View Post
    Powered by large electrolytic capacitor bank charged with adjustable DC (lab) power supply.
    12x 68mF 35v caps in parallel, controlled with beefy parallel pack of mosfets. Results in short current pulse of few thousand amps that takes care of the spot weld.

    This shows somewhat similar unit in operation
    https://www.youtube.com/watch?v=6DbKR4-FMDA

    Waiting to get 100% nickel strips from china, current ones are nickel plated steel and make lots of sparks when welding..
    very neat! Would love to see pics of the finished tab welder. I bought a Malectrics arduino tab welder and a 60C 3S li-po battery to run it with. Works a treat. If you want more current carrying capacity and a wee bit of heatsinking for the cells, you can spot weld through 0.1mm copper sheet very effectively. Lay the sheet on top of the cells, the nickel strips on top of that and then spot weld the nickel to the cells. How are you going to control the pulse duration? From the pack that I built there's definitely a sweet spot between not making a good weld to blowing a hole in the nickel strip.

  7. #1567
    Join Date
    Dec 2016
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    Helsinki, Finland, Europe
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    I can control the pulse width by arduino and/or by charge voltage. I wrote the dual pulse functionality also to my software in hopes to ”seat” the electrodes and make quieter bangs..
    Actually managed to blow up the mosfets, time to order something proper instead of what was found in drawers..

    I was considering the battery version also but I’m not huge fan of sparks and car batteries or lipo pulsed to crazy currents.

    Does the lipo also output enough current that the cables are jumpind around? Capacitor powered version causes the cables to jump nervously..��

  8. #1568
    Join Date
    Oct 2012
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    San Antonio TX, USA
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    2,832

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    very cool! I think mine mightdo the "double tap" pulse, but I'd have to check. From what I remember the first pulse is 10% of the duration of the main one. My cables definitely jump around, scared the crap out of me the first time. According to the specs the battery can safely sustain a 300A draw (60C x 5Ah capacity) until depleted - doing 60 or so welds took about 1/3 of the capacity, though the cables were getting fairly warm by that point. It has enough power to blow through the battery terminal...

  9. #1569
    Join Date
    Jun 2019
    Posts
    108

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    So far, 50 spacers parted from 1/2 X .049 seamless steel tube, pit a chamfer on each end with the parting tool. I placed a piece of 3/16 round in a chuck in the tail stock and pushed it into the tube to catch them, took about 2 hours including setup and programming.


    Then some Victaulic grooves in 6" PVC pipe.


    They get a 6 1/6" bore with a 45 Deg. chamfer at the bottom.


    Then lunch

  10. #1570
    Join Date
    Apr 2017
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    Kelowna BC
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    2,632

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    Bented, tubing spacers can have tough burrs internally. sometimes easier to remover them by rapidly moving bushing up and down a piece of redid rod. if you drill solid stock, then part, it is often easier to deburr, and cheaper to makem due to tubing cost being double or more of solid bar price.

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