Table for my mill

[Vinny]

The problem was with the welder. Not me, the actual machine. I could hear the feed pulsating. Perhaps it's too tight but it will feed just fine when not welding. Shouldn't be a problem with the mains, it's a short feed from the panel and nothing else is on it (I also use that circuit for the plasma cutter) and nothing else was running.. The tip is new. I did notice that I had to to increase the power when I switched from flux to mig (yes, I changed the polarity). The wire is definitely stiffer than flux wire but this happened when the cable was straight. The steel was ground just before I started.

The cold welds were probably from the flux wire. I intentionally took the pic to hide the welds! To put the legs on I had to grind the welds After the grinding, the welds had full penetration. After grinding you couldn't see where it was welded.

[Mayhem]

Right size liner and tip for the wire being used?

The other thing is to check the contactor in the machine. My single phase mig was doing this and after going through all the 'obvious' stuff, I looked further and found the contacts pitted and shot. Replaced them and the problem went away.

[pepi]

(09-25-2016, 03:52 AM)Vinny Wrote: The problem was with the welder.  Not me, the actual machine.  I could hear the feed pulsating.  Perhaps it's too tight but it will feed just fine when not welding.  Shouldn't be a problem with the mains, it's a short feed from the panel and nothing else is on it (I also use that circuit for the plasma cutter) and nothing else was running..  The tip is new.  I did notice that I had to to increase the power when I switched from flux to mig (yes, I changed the polarity).  The wire is definitely stiffer than flux wire but this happened when the cable was straight.  The steel was ground just before I started.  

The cold welds were probably from the flux wire.  I intentionally took the pic to hide the welds!  To put the legs on I had to grind the welds   After the grinding, the welds had full penetration.  After grinding you couldn't see where it was welded.

 Pulsating feed, and still burning?

Sounds like the wire speed is fast and bottoming out or hitting the surface before it has become molten.  If you are sure of the heat range, dial back the wire feed, small increments.  Can also raise the heat to get the surface to a molten state quicker, to accept the cold wire.

  The only way to see penetration is to section the material, a heat halo around the weld area also indicates a good weld.

Unless the welder is particularly old or has had flux core wire run as the primary filler, the liner should be good to go for a fair amount of time. 

My welder is ten years old, has run an easy 80 lbs of wire, .024 & .030, changing the contact tips only. The most frequent need for a liner change is for alum mig welding.

How much does the mill weigh and is your welder 110 or 220 ?


greg

[f350ca]

If the wire feeds smooth when not welding, but sputters when the arc is going I find its usually the contact tip. Seams to start arcing in there and welding the wire to the tip or buildup on the end of the tip.

[Highpower]

(09-24-2016, 10:58 PM)pepi Wrote: Could the drag on the wire spool be to tight, and the wire is hesitating at the beginning. You should have instant wire feed pulling on the trigger.


Cheers
greg

That is actually a "feature" of some Miller machines now. (My Millermatic 140 is one of them.) The wire feed starts at a lower speed when you first pull the trigger, then quickly ramps up to your set wire speed after a second or so. I hate that feature because it screws up MY timing!

The first time I used the machine I thought the drive motor/controller was defective and I contacted Miller about it. The tech I talked to said it is supposed to do that to help prevent sticking the wire on arc starts. The amount of delay changes (milliseconds) depending on your set wire speed. Every MIG welder I have used (including my MM 185) up until this machine has been "instant on, full wire speed" as soon as you hit the trigger so that is what I am used to. Had I known the 140 has this built in delay, I never would have bought it. I just wanted a more portable 110V MIG welder at the time.

[Vinny]

The welder is set for 0.035 wire, it's always run 0.030. I changed the tip a few months ago and I don't use the welder all that often. When I got it, the guy was still on his first spool of flux core and it was over half full (2lb spool). Since then I went thru that and a 1 lb spool of flux.

The welder runs on 220. It's an HF, but it's the one made in Italy (Hobart's assy line as I recall).

The mill weighs 300-350 lbs. It's mall but not a mini. Pic here: http://www.metalworkingfun.com/showthrea...6#pid38856

I should take a look at the contactor, since I haven't even opened it up. I should also recheck my wire feed speed. Perhaps it is too fast. And while I'm at it, take a good look at the tip.

[the penguin]

Did they change the polarity for flux core and not change it back for gas wire

[Vinny]

Inside the side cover where you change the wire are the polarity connections and a sticker by it saying what the polarity should be for either flux or mig wire. It's set correctly.

[Roadracer_Al]

Here's my take: you have high amps, and low wire speed. The high amps burn the wire quickly, and the low wire speed isn't keeping up with the burn rate. Sometimes this is bad enough to actually extinguish the arc, but usually it just pulsates. Look up the correct amperage for the thickness and materials being welded. then set the speed intentionally low, so it sputters, then slowly dial up the wire feed until it sounds just like frying bacon. It ought to be loud, continuous, and aggressive sounding. Positively sizzling.

[Dr Stan]

Never have liked flux core.  The first wire welder in my home shop was a Campbell Hausfeld made in Italy & was from a farm & ranch store .  110v unit which I quickly changed over to MIG giving me a huge improvement.  I used it with good results outside with 4X8 sheeting blocking the wind.

Sold it prior to moving to KY and bought a Miller 180 shortly after setting up my shop.  Since I'm not trying to weld together battleships and large bulldozers it does everything I want including aluminum welding with the optional Torchmate.