Free 173 Best Homemade Tools eBook:  
Remove advertisements
Results 1 to 3 of 3

Thread: Improvments to the common spotwelder plans

  1. #1

    Join Date
    May 2015
    Posts
    3
    Thanks
    0
    Thanked 3 Times in 2 Posts

    Improvments to the common spotwelder plans



    So I was thinking about making a spot welder. Very common project to the point KingOfRandom has done it, the youtube channel where ideas go to die.

    I was wondering if anyone who has expierence using spotwelders could suggest relatively simple improvments to the common idea.

    I was thinking about adding a small fan to cool the transformer for a start. Possibly a fan salvaged from the microwave I get the transformer from.

    Guy in the video mentioned a timer. Not quite got the electrical skill to know how to go about that but if someone could explain it that would be nice. If anyone else has ideas to give please bring them.

  2. #2
    Toolmaker51's Avatar
    Join Date
    Feb 2016
    Location
    Midwest USA
    Posts
    1,024
    Thanks
    2,206
    Thanked 1,051 Times in 585 Posts

    Toolmaker51's Tools
    Rainbows;
    How goes your project?
    I'm interested in this as well. So far, I've collected the outline and things to consider.
    First impression is capacity of a microwave transformer and gauge of metal you'll work with.
    Next is what your electrical service is. Bigger handheld units are 220 single phase. I wouldn't want smaller.
    It also seems like an arc welder with incremental amperage would be a good source of power, build a tool that plugs in.
    Building one, the main task is the squeeze and contact mechanism.
    There is a break in commercially made welders from fan to water cooled, related to power and duty cycle. Water cooling runs a little heat exchanger, a auto heater core size, and jacket is within the arms holding the copper tips.
    At work, ours has a timer sensitive to partial seconds, with a vernier style knob. Newer machines are probably digital.
    Sincerely,
    Toolmaker51
    ...we'll learn more by wandering than searching...

  3. #3
    Frank S's Avatar
    Join Date
    Aug 2015
    Location
    Peacock TX
    Posts
    2,472
    Thanks
    450
    Thanked 2,221 Times in 1,085 Posts

    Frank S's Tools
    There have been literally 1000s of small light duty spot welders made from salvaged microwave transformers As I say light duty, although many U tube vids boast such claims as 500 to 900 amps output all of those claims are based on faulty data assumptions
    I built 1 of these transformers just to see what it would do for my secondary wire I had 00 ga battery cable since I wasn't planning on completing a spot welder I just crimped a pair of cable ends on it then vice gripped a couple of used mig welder contact tips to them it would spot weld 2 pieces of 24ga metal together but not very fast
    for a good spot welder you could remove the transformer from an ac stick welder retain the primary windings and re wire the secondary winding for a 3 to 5 volt output use the formula of 2 turns per volt with as many in hand parallel wires as will fit.
    to yield the amperage output A simple adjustable core AC stick welder makes the best transformer to use
    For a timer this is also easy buy an octal timing relay and base socket with a 120 or 240v coil depending on your input voltage wiring instructions will be included in the package they come with 20 amp rated contacts but a heavier timing relay with 50 amp contacts will last longer.


    Post your reply!
    Join 33,912 of us and get our 173 Must Read Homemade Tools eBook free.



    173 Must Read Homemade Tools
    Never try to tell me it can't be done
    When I have to paint I use http://kbs.justoldtrucks.com/

  4. The Following User Says Thank You to Frank S For This Useful Post:

    Toolmaker51 (05-23-2016)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •