Re: 110vt buzzbox questions

>>>Years ago, at least 20, I snagged an elderly Marquette 110vt buzzbox.
>>>
>>>Its always been an utter pain in the ass to weld with, as it seems to
>>>be nearly unable to maintain an arc. Open voltage is right at 34
>>>volts, not measured under load.
>>>
>>>Data plate shows up to 90amps, 30volts open current, so it SHOULD be
>>>able to burn 3/32 rod well enough. Line voltage is 124volts, on a 50
>>>amp circuit. with a sag to 122volts when I strike an arc. Or try to.
>>>
>>>There is no reactor(?) coil in the machine, just a hefty transformer,
>>>with 3 taps, Low, Med, High
>>>
>>>I dragged it out over the weekend and tried welding with it since my
>>>skill level has increased a smidge since I got it .
>>>
>>>Its still a pain in the ass. Even with 3/32 rod of various types, it
>>>will bearly maintain an arch, but the rod turns red very quickly and
>>>sags, even though it wont burn properly.
>>>
>>>Is this an indication of too low an arc voltage, given that Ive good
>>>reasonable current..enough to sag the rod.
>>>
>>>Ive tried 1/16", and its not a hell of a lot better, with 6011/6013
>>>etc being tried in all sizes.
>>>
>>>Would I be served by making a reactor (?) choke(?)
>>>
>>>Chuckle..this is simply a fun thing, as Ive got other..better..welders
>>>to use.
>>>
>>>Any of you technical guys give me a heads up ?
>>>
>>>Gunner

>>
>>Short answer: there isn't much you can do to make that box work well
>>because its open circuit voltage (o.c.v.) is so low.
>>
>>Stick welding with a stable arc requires a power supply that is
>>essentially a current source -- that is, a power source where current
>>has little dependency on load (arc) voltage. Copper-iron
>>(non-electronic) machines do this with reactance in series with the
>>load. Higher reactance results in more constant current, but it also
>>requires higer o.c.v. to produce desired arc current.
>>
>>The reactance may be a separate reactor, the result of deliberately
>>loose coupling in the transformer, or both. Arc current can then be
>>adjusted by adjusting or selecting reactance, o.c.v, or both.
>>
>>One thing you can do with those little boxes is carbon arc brazing
>>when O/A equipment isn't available or you're outta gas and a long ways
>>from any.

>
>A thought: I wonder if running DC would help. I really don't know,
>but it'd be easy enough to try. Scrounge up some big honkin'
>rectifier diodes, maybe even sets of alternator diodes, and make a
>bridge rectifier. Experiment with electrode polarity to see if one or
>the other works better than AC with that box.
>
>An aux reactor on the DC side might help considerably. That has a
>different function than the reactance on the AC side; it serves to
>keep the DC arc going during periods of zero voltage when the AC
>supply reverses 120 times per second. I once made a reactor out of a
>good-sized old transformer core, made the "winding" with strips of
>roof flashing interleaved with brown kraft paper, this on a buzzbox
>with a set of rectumfriers. A strip of .012" x 2" is about equivalent
>to 6-gage wire and a hell of a lot easier to wind. It can also
>handle more current because it has much more surface area for heat
>dissipation.
>
>It worked pretty well! I could even TIG with that kludge.
>
>You did say this was a "just for fun" project, right? <G>

>
>-----
>
>Speaking of just for fun: yesterday a shootin' buddy showed me a
>electromagnetic "cannon" he and his kid made. He scrounged a bunch of
>disposable camera carcasses (with electronic flash) from a Walgreens,
>telling them it was for a school project. Took the caps out of 4 or
>5 of 'em, paralleled them up in one unit. Wound a coil around a
>tube. Used the flashtube as sort of an ignitron-type "switch" to dump
>the 300-volt caps thru the coil and flashtube. The thing shot a
>clipped-off 4-penny nail quite a respectable distance in the parking
>lot.
>
>They made another one that is a ring launcher, launches an aluminum
>washer out of a disc drive. It punts the washer maybe 18' -- but if
>the washer is dunked in liquid nitrogen first (reduces resistivity)
>it'd bounce it off the ceiling.
>
>Kurt Vonnegut wrote: "make no mistake, we're put on Earth to fart
>around." (Timequake)