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This may be a dumb question but I figure the only dumb one is the one not asked. I know it would be impractical to build a phase converter for one of the old three phase rotary DC welders. Has anyone ever refitted one with a single phase motor?Or what kind of trouble would it be to couple up a small air cooled engine. I've never dealt with one of these machines before I just like to tinker and have noticed a lot of the machines cheap on Ebay right know.
Reply:The drive is a standard three phase motor, so a phase converter should turn it. Whether it would be useful for welding.... it depends. With a static converter (capacitor type), your power rating will be cut roughly in half, and at that the power efficieny will also drop. The input current rating is the main part of the limit, but it wil also run at a greater slip and with a worse power factor for a given load. I have nve tried this with a welder, but when properly matched, they work fine for machine tools.With a rotary converter, I don't know. I woud guess that if your feed to the rotary is sufficient and the rotary is properly sized, you could run full power.With an electronic converter, or a VFD, shouldn't be a problem IF the conerter is rated for the loads that go from none to max and back on short cycle. That would be something to inquire of the manufacturer. It would also be about as expensive as just buying an inverter-type welder if you have to pay for it.
Reply:Actually, the verticles did come in a single phase motor drive, as an option, but I never got inside of one to see if the mechanicle structure of the drive section was different from a 3 phase machine. A rotary convertor would probably work well, assuming it was sufficient to withstand the changes in load these machines produce from idle to arc. I don't thinnk the machine itself would contribute to the conversion though because they run at 3450, and convertors usually run slow for best results.It would probably be possible to belt drive one from an engine, especially a horizontal, with some modification, but if I was looking to build a belt driven machine, I'd look for one of the old Hobart PTO units, as they were already set up to do it.You also might want to look at the Lincoln site, and see if there are drawings of the mechanicle construction of the machines.Appreciation Gains You Recognition-
Reply:this site has some belt driven/ pto drive weld unitshttp://www.surpluscenter.com
Reply:BM, those at Surplus Center are aircraft generators.Hobart, before they became HoFart manufactured some real nice PYO driven units, many went in the back seat of Jeeps for the military. Every once in a while one turns up on Ebay.Appreciation Gains You Recognition- |
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发表于 2021-9-1 00:26:05