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I finally fired up my Millermatic 180 this weekend,using the supplied .030 and straight co2, local company only deals in 220cft tanks so I have plenty gasI only had some 1/8" thick angle and 1.2mm rhs section to experiment with.It appears that either the chart settings are way to high or I am doing something wrong aswith the recommended settings for 1/8 I was getting holes very easily.I was only able to manage better when I turned down the voltage setting to 18ga and then play with the wire speed from there. Did both push and pull, I found it was safer with pull as push tended to get holes easier.I suspect my travel speed is too slow, however I am unsure of the relationship between the three(voltage, wire speed, travel) or at least what speed I should aim for, or should the puddle size be used as the primary guide and move before it gets too big and drops out.
Reply:Porosity is usually caused by dirty metal or lack of sheilding gas when using solid wire and gas.Was your metal clean? It is best with solid wire and gas to grind off all the mill scale and clean off any paint, grease, rust, etc. in the weld area.What is your gas flow set to? 20 cfh works fine for most circumstances.Was there a breeze blowing? A breeze will blow away the gas. Put up a wind break, take the work inside, shield the weld with you body and free hand, or switch to self shielding fluxcore wire.What stickout length were you holding. Keep the tip to work distance no more than 1/2".Is your gas nozzle clean? Spatter deposits inside the nozzle and on the diffuser can mess up the gas flow/coverage.Is your nozzle all the way inserted on the torch?What angle are you holding the torch to the work? Laying the torch back too much can cause poor gas coverage. The nozzle should be close to vertical, about 10 to 20 degrees back.Finally, travelling too fast causes poor fusion, poor penetration, cold toes, or undercut if the heat is high enough, and uneven ropey looking humped up weld bead. Watch the puddle. Keep the wire on the leading edge of the puddle, but don't overrun the puddle and get out ahead of it. Keeping the wire too far back in the puddle is travelling too slow and cause the weld to be overfilled and toes to roll out and lap over. Move the torch at a consistent speed and watch the toes for even bead width as you go along.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:The figure that miller give for heat and wire speed should be really close if not right on. Keep in mind that MIG is a high speed process when you get it right. Once you have a puddle get moving but as said earlier don't out run the puddle. Having said that now set your machine as miller states and try to out run the puddle. Keep increasing travel speed slowly and when you do out run the puddle slow down a bit and you'll have it. Once you have it you'll hear that very distinct sound of a MIG running right and you'll be able to weld by ear when you have to.Tough as nails and damn near as smart
Reply:yes, everything was more or less clean, gas was set betweel 20-30.I had the tip pretty close, maybe my angle was a little too much but not by much.I think my travel speed was the main issue. Definitely didn't have cold issues.Will go again later this week and post some pics.
Reply:I did some more tests last night trying to get a faster travel.I realize my main problem right now is I am using an old aquarium table frame as my welding table and it's only 32" tall whilst I am almost 6', so I am hunched over and cant move my arms easily to experiment with control.First project this weekend will be to try extending the legs.Was able to run some beads close to the factory charts on 16ga rhs.Push was safer, I find that when pulling it is easy to have wire stray in the trailing edge of the puddle and burn thru. There is a cold bump at the start though. |
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发表于 2021-9-1 00:41:56