You will not be surprised to hear that in 2004 pulsed power sources are the majority of the weld equipment purchased for robot cells. The weld reality is that both the MIG manual and robot MIG weld industry will get better weld results on most steel and stainless applications with a lower cost, more durable, traditional CV MIG power source. The following photos of MIG manual weld samples provide fundamental visual evidence that traditional, low cost, CV equipment can provide superior weld results than the more costly, less durable, pulsed equipment.

 

 

 

Ed welding the spray and pulsed welds 2004.

The following weld comparisons were made using a low cost MIG power source, the Lincoln CV 300, (the Lincoln CV 400 provides the same results and can be interfaced with a robot). The Lincoln CV 300 costs approx. $2000 and the CV 400 would cost approx. $3000.

Compare what you pay for your robot weld equipment. The CV 400 robot MIG package, including wire feed and interface, would sell for approx. $6500. For those tier one companies who get a thirty percent discount on the weld equipment they purchase, did you pay more than $4500 for your robot weld package, (power source and interface). Every penny you spent over this price was a penny thrown out of your window.

The Lincoln CV 400 in my opinion will outperform the Lincoln pulsed Power Wave 455 and any of the Miller, ESAB or Japanese pulsed equipment. The Lincoln Power Wave unit including a wire feeder and interface will retail for around $14000.

The Lincoln CV 400 is I believe also superior to the CV Miller Delta Weld equipment. The CV 400 would be my first choice to attain optimum steel / stainless spray transfer welds. In this segment the Lincoln CV welds are compared with the Lincoln Invertec, an inverter pulsed power source which sells for approx. thirty percent more than the CV 400.

PICTURE ABOVE: With an 045, 1.2 mm, E70S-3 MIG wire and an argon - 10% CO2 gas mix.
Ed ran the 0.045 wire at a high wire feed rate of 450 ipm. The 450 ipm is an optimum wire feed rate for many auto / truck frame manufactures, robot welding steel parts 2.5 to 6 mm.

The 450 ipm wire feed rate with the 045 wire and resulting steel weld deposition rate will run 4 to 5 mm fillet welds at a robot travel rate of 40 to 50 ipm, or produce a 1/4, 6 mm fillet weld at a robot speed of 20 to 22 ipm. Note with this untouched fillet weld sample, no weld spatter, and the "flat" smooth weld surface. Take note of the weld's straight edges which indicate consistent weld transfer and consistent weld fusion.

045 1.2mm steel wire set at 350 ipm.

Picture above. The pulsed weld on left sample made with the 045 wire, versus the CV spray weld. Both welds were made with the wire feed set at 350 ipm delivering approx. 9 - 10 lb/hr. When set at 350 ipm, the 045 wire is in an "optimum" pulsed wire feed setting. The 045 wire set at 350 ipm is also the approx. "start point" of spray transfer weld. Again note the pulsed weld inconsistency is clearly evident in the convex surface and inconsistent weld edges. When sectioned, you know which weld provided superior weld fusion.



If you want robot weld stability at high weld deposition rates, pay $6000 rather than $12000. If you wasted money on pulsed MIG equipment and want to improve weld fusion or arc stability go over to that costly pulsed power source and switch over to spray transfer.

 

O45 steel wire set at 450 ipm

Picture Above: Again you can see when the 045 wire is set at 450 ipm, (approx. 13 lb/hr) which weld is considered optimum. The 045 1.2 mm wire set at 450 ipm is used on many robot welded parts >4 mm. As the picture indicates, the spray transfer weld is again superior to the pulsed weld. This one picture tells you why auto industry executives and engineers have wasted millions of dollars on paying an expensive premium for electronic pulsed equipment that has not created any steel weld benefits for their plants

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045 steel wire set at 550 ipm

PICTURE ABOVE: Of course if you want the maximum possible MIG weld deposition rate or highest ROBOT weld speeds from the robots on steel parts > 8 mm you will use an 045 wire set around 550 ipm, 15 to 16 lb /hr. This is a wire feed setting you don't want to set with that costly pulsed power source. One thing you can say for the pulsed low or high wire feed rates the weld inconsistency is consistent.

ITS ALSO TRUE WITH 035 WIRES

PICTURE ABOVE: With the 035 wire and argon 10% - CO2. Ed opened the wire feed control to it's maximum setting and provided a wire feed rate of 700 ipm. Again look at the spray weld on the left versus the pulsed weld on the right. The pulsed weld with the 035 wire indicated the same weld pattern as the 045 wire. Pulsed was again more convex and the side wall weld fusion was again less inconsistent than the spray weld. Again note both welds are untouched with no spatter. Some companies will pay $8000 or more for that pulsed power source.

 

 

035 SET AT A MID RANGE WIRE FEED RATE OF 550 ipm
you know which is the best weld.

Picture Above. Again note the 035 wire comparison of the pulsed mode versus spray transfer weld. In the pulsed picture on the right, the welds are made at a mid range wire feed setting of 550 ipm. As the weld indicates again the traditional spray mode shows more consistency in the metal flow rate. Again both welds are untouched and both weld show no spatter. When the welds were cross sectioned the spray weld provided superior side wall weld fusion.

 

 

There were well over 2000 pulsed power sources sold for steel robot weld cells in 2004. That's at least ten to 12 million dollars down the drain this year for an industry that is always looking for ways to cut costs.