Need help with Miller spot welder. It's a LMSW-52. I bought at auction while back and don't really have a steady use for it, but sometimes something comes up and I'll try it. At first it would weld but now I can't get any heat out of it. The transformer hums but no weld. Any tips on what to check or look for would be greatly appreciated. Anybody have one of these? kk
Miller has manuals for almost all of their "modern" products; yours should be here:
On my Miller, the top tong moves to clamp. It is electrically connected to the welding supply with a stack of copper straps or braided copper flat cable. Check the connections here and see if they broke.
Four things needed for proper spot welds..Heat, current, time, and clean, properly prepared tips of the proper material. Dirty tips are a likely culprit, if you have used it before. It is a sensitive area. Lightly sandpaper and retest. I assume you're attempting to weld steel? Nonferrous materials like brass and such require capacitive discharge welders, in my experience.
RJ
Measure the voltage on the arms when 'running'. Voltage ?
If so - then there is oxide in the threads and this limits the current in the tips. Perhaps the almost pointed tips are plated. Look at them - can they conduct ?
What are you trying to weld - some light steel strips ? or just the tips.
Mart> Thanks for your reply. I will check that out.
If the transformer is good, and the tongs are making a good connection, I would zero in on the tips. MAke sure they are clean and that the diameter of the tips do not exceed Millers recomended tip diam size and that they align with each other and make full contact. The metal your joining has to be relatively clean between them if its near the max thickness of the limits of the machine. On thinner metal it may work ok with slighly more dirty metals but the cleaner the better. It sounds like your not making real good contact between the sandwhiched layers of metal and the welding tips. Make sure there is sufficient toggle / tong clamping pressure as well. Snug but not overly tight. Visit my website:
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