Using ridiculus WFS to "save time".

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Ok, I need some advice, knowledge information here.Just for the information baseline, my boss (Company owner) bought 5 new power supplies at 10K a pop with the philosophy that we can run at 800 IPM, thus require fewer welders (Men, not machines) and still put out the same productivity. However, our welders are anyone with a pulse, off the street, most with little or no experience. 85% of our welding is 1/4" - 1/2" steel, with some components up to 6".Though the IPM has doubled (from 400 IPM original conditions) I really don't see a difference in arc-on time for a weld the same length.  I noticed if I run it too fast to avoid excessive penetration, the weld bead is ropey and thin, but if I weld slow enough to get a proper fill, the bead is a little wider and the arc-on time is the same.The heat is beyond intense and it's burning up the liquid cooled torches and the welders hands. The lead is even too hot to touch. Now he wants to run .052 and possibly 1/16", thinking we'll get even more weld laid in less time.   (BTW, he has absolutely no welding experience but won't take no for an answer.  GREEDY????)If we go to .052, can we decrease the IPM and get the same size bead we are getting now with .045, and produce less heat?  I'm going to order some .052 and give it a try, but was wondering if any of you experts out there have some knowledge, facts or information that may be of any assistance.
Reply:but I have had an incident.  I was doing some shut down work for a mobile home plant a while back, and looked in on there chassis shop.  All of the frames they fabricate were in the 1/4in range.  Every machine they had was a 500 amp power source pushing large diameter wires.  When i asked them why they ran that kind of setup they said to increase production. I took one of the machines, and ran a few beads with it, and never got a weld that satisfied with me.  It was putting too much heat to the joint, which of course led to more distortion.  Even when I sped up travel speed the welds still looked bad.   Considering the fact that your boss has no welding experience I would try to talk him in to hiring a consultant who can come in.  I have found that most bosses don't like to admit the guys working for them may know more than they do, and it sounds as if your boss may be like that so an outside consultant may be able to persuade him to a better situation.  One thing your boss should consider is that if the guns are getting so hot that welders can't deal with them then he is going to loose production from that alone.  A comfortable worker with supply more production than one who isn't thats a fact.  I have done some work for some people who just had to have it there way even it it was a better way.  I feel fer ya.   Good luck  ~JacksonI'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Go To Weldreality.com Ed Craigs Site And Read His Thoughts And Recs On Wire And Power Supplies. Buy His Book Pricey But Worth Every Penny, I Have Used His Numbers In Setup And My Welds Are Better And I Am Not Spending Time On Cleanup.  My .02 WorthChipmasterRanger 250LN 252 ESAB suitcase feedersSP135LINCOLN Square Wave TIG 255Kondia vert millProtoTrak CNC vertical mill13" South Bend Lathe17" South Bend Lathecaterpillar d-4, 15, 22 and a 20
Reply:We got some hardly used units like you describe and the boss also made the same comment.  "Now that we have these things we will be able to weld twice as fast."  I corrected him right away.  We have almost no down time and our contacts tips last all day.  That is the advantage.  Also they don't consume juice unless you are welding.When we turn ours up over 400 ipm  on .045 metal core the beads get ropy and fillets can roll over and give you cold lap on the lower edge.  I'm not much of a welder and had a bad time of it so I asked my foreman to run a bead for me so that I could see what I was doing wrong.  he managed to get a relatively flat bead at 420 ipm and 28 volts by keeping a stickout of half an inch.  He had the nozzle tight in there and it flattened things out.  To get a decent shape to my multiple passes I backed off and ran 360 and 26.5  I was in control and got a nice bead.You have started a rant... there is a limit on the maximum heat.  There is a formula that gives it in Joules per inch or foot.  Once you exceed that limit you create bad welds.  Some codes are now limiting energy input per pass.  It is STUPID to try and increase welding speed.  These guys listen to a welding salesman and are fooled.  Welding is only a small part of a production picture.  In many cases 75 percent of time is spent in handling.  That is loading and unloading trucks, moving material from work station to work staion and cleaning.  It is esy to time a welder rather than watch him waiting  for a crane or forklift.
Reply:I did some parameter tests and showed the owner.  What I found was....On a six inch weld at 400, 500 and 600 IPM using .045, there was only a 2 second difference in arc-on time from the 400 to the 600, so average saving 1 second per 100 IPM increase.  The weld bead also increased by 1/16 of an inch for every 100 IPM increase.With the increase of WFS came an increase of heat, which burned out more parent metal and required more filler, so the travel speed really didn't decrease.  If I tried to run at a faster travel speed with those settings, the weld was very ropey and unfilled along the edges with extreme undercut.I showed the data and sample pieces to the owner and though he said he didn't like the increase in weld size, the ropeyness with a faster travel speed, he wanted me to find some way to increase travel speed (decrease weld time) and get a non-defective weld.  Right now, until I accomplish doing what experts and welding scientists have been trying to do since before I was even born, we are running a happy-medium.....result, 500 IPM and will do same study on .052 and 1/16 and compare all to .045 as well.  After that I'm calling in the calvary.FONT=Century Gothic]Try the rod. Buy the machine.  You only live once, and can weld every day.[/FONT]
Reply:I am not an expert in the area of industrial welding or engineering, but what y'all are talking about sounds like a standard constrained optimization or maybe even a simple linear programming problem.  You have several equations, with possible/probable interactions between terms.  If you can accurately formulate the process into equations, then you just solve to figure out the outer envelope/surface of speed, wire size, amperage, and other variables in the process.  If you could convice the boss to hire a engineer as a consultant to collect and analyze the data, you might be able to get a table to go by.  However, one thing it sounds like no one has talked about (maybe boss included) is the costs element.  When trying to maximize profits, the boss should be keeping his eyes on minimizing costs per unit of output.  Anytime you try to push out to the outer edge of any technical process, costs increase...and generally increase at a geometric rate.  This means that getting a few more inches per minute might cost more in energy consumption, tool wear, and other potential costs than is saved in wages.  If the unit prices increase (or profit margins decrease) because of the increase in speed, you have gone past the point you want to be.A good analogy on costs comes from the car industry.  Most cars will go 100mph, but to overcome air resistence and achieve progressivly higher speeds, geometrically more hp has to be added and that generally costs geometrically more $.  A new car that goes 100mph can be had for $15,000.  One that goes 200mph will set you back probably $150,000 or more (ten times more), not $30,000 (twice as much).Smithboy...if it ain't broke, you ain't tryin'.
Reply:As a point of clarification to the above post, I am using some terms (like profit) a little loosely, but I hope you get my point.  BTW, I meant to say that if the average unit price increases, you have gone past where you want to be in most cases (not the marginal unit price).  The main thing is that you actually have two things going on 1) a technical process and, 2) an economic process.  They are intertwined, but different.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Smithboy I can see your point but the area that needs attention is the less glamorous and often needs little engineering expertise.  I have seen too many operations where supervisors are watching the clock and timing floor to floor operations.  The boast about saving one minute on a ten minute operation but don't look at how long it took to spot the material beside a machine tool or welding machine.  They push for the maximum speed welding and then ignore the time spent removing spatter and preparing for paint.  They ignore a crane that is slow and requiring servicing that holds up production.  They ignore people waiting for a forklift trying to look busy.  They look for some high tech solution when all these simple little flow problems are staring them right in the face.
Reply:Smithboy I can see your point but the area that needs attention is the less glamorous and often needs little engineering expertise.  I have seen too many operations where supervisors are watching the clock and timing floor to floor operations.  The boast about saving one minute on a ten minute operation but don't look at how long it took to spot the material beside a machine tool or welding machine.  They push for the maximum speed welding and then ignore the time spent removing spatter and preparing for paint.  They ignore a crane that is slow and requiring servicing that holds up production.  They ignore people waiting for a forklift trying to look busy.  They look for some high tech solution when all these simple little flow problems are staring them right in the face.   What angers me is that an engineer in North America never has to wear a pair of coveralls in his lifetime.  A European trained engineer is required to spend time in production positions in order to qualify for his professional status.  These people have done the walk while the tie and white shirt graduates are only good in a research lab.
Reply:Actually, I was talking about all of it, spatter removal and all.  Like I said earlier, if you can break down ALL aspects of the operation into a mathematical model, leaving nothing out, you may be surprised to find out that YOU are right not the boss.  Often times, like you say, the focus is on the actual task and not on staging the task.  A good engineer or motion studies expert will see all of it.  Once you factor in the costs of new welders, consumables, power requirements, etc., it may be that the cheapest way to make the product is with lower amps and more time, cause the labor savings may not be sufficient.  I used to work in a plant that made plastic knife, fork and spoon packets like you see in take-out orders.  They had figured out on each production line (to some extent) when it was better to speed up, when to add another person and when to bring another line up.  They didnt base it on a consultant's study, but we had a good plant engineer that had a good feel for the process.  He actually had made up a spreadsheet in excel that he used to model each lines' output.  Different process, I know, but similar principles apply. We in the US tend to focus on saving labor, cause it has been the relatively expensive input, compared to labor in other countries.  But, one of the biggest advancements in the central asian agricultural industry was a hand-held hollow pole planter that despences one kernal/seed into the ground each time it peirces the soil...like using a walking stick.  Perfect spacing and it conserves seed and machinery, both of which were relatively expensive there at the time compared to labor.  They had lots of cheap labor.  So rather than using a seeder tractor, they had a hudred or more folks walking and planting.  The point being we may need to take a new look at some processes.  Labor may not be the most expensive input anymore.  You might actually find out that it is really cheaper in the long run to add another welder and use less amperage.  But a good engineering consultant can figure that out.  My guess is that it will confirm what you have been saying.  Your boss may be like my kids, they dont listen to me, but if someone else says it, somehow that's different.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Could be you guys are over analizing this too..    Many times the next level boss is just some smuck who is subject to quarterly reviews. "Improve Processes" and "Cut Costs" are goals that have been placed on his review and blanks he is desperate to fill. He could care less about the long term health of his company, design issues, quality issues or acheivability. He just needs to do something that manifests itself in the next thirty days or he is in deep doodoo.  On the humorous side, over zealous supervisors will eventually drive themselves into ulcer country. What they fail to recognize is that even after a process has been "improved" into oblivion and "costs" have been cut to zero, he'll still have those same two blanks to fill on his next review.
Reply:Have any of you been involved in "'Lean" manufacturing?  It's based on principles developed over the years at Toyota.  One of the basics is "Right sized" equipment, basically a bigger or more powerful machine is not always the answer.
Reply:Sandy, I guess I agree to some extent, but I am an economist/economic analyst, so keep that in mind (we always recommend more analysis  ).  But the comment by Dendog69 is sorta to the point I am getting at.  There is an optimal scale of production for most any process given the costs involved.  Once that is found, it is better for a company to build a new manufacturing capacity and replicate than to expand production on the existing equipment (in the long term).  This can be found by luck and eyeballing, but good info is always a big help.  The best example of this principle that I can think of comes from waffle house and wal-mart.  Waffle house has experimented with a lot of different size operations, but have found that it is more profitable to put two restaurants across the street from on another than to build a bigger restaurant.  Wal-mart continues to build larger stores because, apparently they havent found the right size yet (probably once wal-marts each have their own zip code).  Point being, businesses expand because they want to take advantage potential profits due to rising prices (from increasing demand or decreasing market supply) or from cost savings in production or from volume discounts in inputs.  Based on everything posted, it might be that pushing production up with more heat, speed and thicker wires, in this particular case, is moving past the point of efficient production using this equipment and it's time to expand the number of lines.Maybe suggesting a consultant is overkill, but when you start spending thousands on equipment that provides no added benefit in output and may in fact increase defects, it is time to start thinking about some outside help.  This can be tricky for a boss to initiate, though...and even trickier for an employee to reccomend to a boss, I am sure you know what I mean. Last edited by smithboy; 09-12-2005 at 10:19 AM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:I will probably get myself in trouble here but I believe if using 100% co2 and with some practice any weld done with .045  can be done just as well and faster with .052. Verts would be about the same. I think you should give it a try. I went threw the same thing years ago did all the cussing and bitching but now I believe it was a good change. We moved from .035 to .045 to .052 welding on 3/16" to 1/2" plat mostly flat. I remember my first weld with .045. It was on 4" channel on end. After I welded the first side I went to the other side but the first weld had already formed a bead on both sides. needless to say I turned my heat down a tad.