Management: Robots and MIG Weld Process Controls. Part 2.
INDUSTRIAL CONSEQUENCES OF WELD PROCESS APATHY AND IGNORANCE
Weld process ignorance has for decades retarded weld process and consumable evolution and has also dramatically increasedd the average weld
/ manuafcturing companies weld costs and weld rework potential.
 Weld ignorance has made simple robot weld applications appear complex.
Weld process ignorance adds to poor and confused weld shop culture and
generates numerous weld shop myths.
 Weld process ignorance closes the door to logical, cost affective weld equipment - consumable selection.
Weld process ignorance opens the door to biased - ignorant weld sales advice and to
the purchase of less than optimum weld consumables and useless, costly electronic
bells and whistles.
Weld process ignorance has created the common weld shop enviroment where many managers, engineers and supervisors
seem to devote too much of their time chasing weld shop issues rtaher than resloving them.
Weld process ignorance has hidden the real cost of welds and places weld cost
focus on invoice items like the cost of weld wires or gas.
Weld process ignorance ties up plant personnel resources
who will during weld team meetings waste valuable man hours trying to resolve
weld issues that should take an individual with process expertise minutes to resolve
 Weld process ignorance always reduces weld safety.
 Weld process ignorance dramatically increases a companies weld product liability.
ARE YOUR ROBOT WELD REJECT BINS OVERFLOW.
those robot weld reject bins fill too rapidly and the production management is
trying to decide if the reject bins are "half full or half empty", many managers
in their weekly production - quality reports will tend to blame;
 the robot operators,
 the robot programmers,
 the robot equipment,
 the robot
 the robot fixtures,
 the weld process,
 the parts,
 the salesman who sold the equipment.
 the intergrator,
 Jesus, Mohammed or Buddha or President Obama.
Robot Weld Process Optimization.
Freight Liner. The following had been implemented at the Freight Liner facility. Major
changes were made in the existing welding programs of the ABB 2400 series robots.
The process control program changes completed by Ed in the first week of Aug, were designed
to improve the weld fusion potential and also to reduce the weld cycle times of
both the HD and LD parts. For more info on these Frightliner robot weld, click
is it the welding department seem to always have the most issues?
Ed: I have been with this company HR department now for almost 20 years. When I think back, the
welding department and it's personnel have always been the area in which we have
had most manufacturing and people issues. I know in the last 10 years we have
likely gone through 4 people who have supervised the weld department. Why is it
we cannot seem to get control in this specific area?
reply: In reality all weld manufacturing issues work there
way down from the plant managers and engineering manager's office. It's possible like too many companies that your management has
never correctly identified the root cause of their common daily weld issues and also they are not aware
of the caliber of the individuals they need to run a highly efficient weld shop.
By the way notice how the you focus on the performance of the weld shop supervision
and the people in the weld shop, what about the performance and quality of the
individuals who hire the ineffective supervision?
manufacturing companies employ managers that have little respect for welding and
minimal knowledge of the requirements for effective weld process controls. It's
therefore logical to assume that the manager's weld process indifference will
have it's influence on the weld shop performance. The common, hands off management will not take on the responsibilty for process and equipment ownership with the manuafacturing products that generate your profits. Any captain on a ship understands responsibity and accountability, few managers in 2013 get it.
IT'S AN OLD PROBLEM THAT GETS WORSE EVERY YEAR:
quality and productivity issues will be more numerous in weld shops in which confused
managers surround themselves with confused supervisors and engineers who are surrounded by confused
employees who get no assistance from their confused job descriptions: Written in 1985.
From my perspective, a
"qualified weld or manufacturing manager" maybe as rare as a bird on
the edge of distinction. I would speculate today, that no more than two in twenty
individuals who claim they have the necessary management expertise to optimize
robot or manual weld production have the capability.
My advice to manufacturing
companies who rely on welding automation, when you get the opportunity to get
a qualified management individual or good weld / robot technician, look carefully at
their compensation. How logical is it when you find a "Mr. Right technician", that
this individual should be paid less or no more than some of the ineffective, engineers
you already employ, engineers who spend too much time in the office, engineers that have been unable to resolve your manufacturing
a company employs a technician with extensive expertise in both robotics and welding,
any management recruiting company would tell you that this individual will be
much harder to replace than an engineer or your corporate bean counter accountant. In companies
that utilize many robots, when the robot weld quality and productivity is optimized
for a manufacturing company the costs benefits to that organization are always
substantial, therefore the remuneration for these services should be easy to justify.
you are one of the unique, few individuals experienced in both weld process controls and
robot programming and you are looking for a job, remember with the dramatic growth
of robots in the welding industry, the manufacturing industry will for a long
time need you more than you need them. Even tho most companies don't understand the expertise required for optimum robot weld quality - productivity, don't sell yourself short, if at the facility
where you work you find the management and supervision are ignorant to the responsibilities
of optimizing welding productivity and quality, then make it your responsibility
to first try to educate them. Print out appropriate parts of this site and place
it in the managers mail box. If the manager is a logical individual they
will get the message. If the management is unresponsive to you, then vist www.monsterboard.com,
use "welding" as your keyword and go and find a company who understands and appreciates your talents.
following add shows why in many instances weld management and
HR personnel are
out of touch with weld reality.
A typical add on the web that indicates managent stupidty.
2008: Wanted engineer or experienced technician
to work for a
fortune 500 company with annual sales over 1 billion.
This major automotive company requires an engineer to manage and resolve their weld, paint and press shop
issues. The engineer will have responsibility to manage the welding production
at four plants that utilize over 200 robots. You will be required to understand
the soft ware of Panasonic and ABB robots, and manage the laser, plasma and resistance
equipment. You will ensure that metal forming, press and paint production is optimized.
You will be in charge of capital expenditures of more than five million dollars
annualy and be responsible to train over 200 personnel. High energy person required
as 60 - 80 hrs hour a week is norm, (overtime not paid).
Salary: We will pay the same
as we did in the 1980s, $55.000.00 to $65.000.00 per year, "depending on
Relocation: Not provided, as we don't think to much about
Education: We fund your education because we know you will never have time to attend educational courses.
above add is typical, and also quite remarkable in it's process and manufacturing
expertise naivety. The Big 3 auto - truckcompanies learnt many years ago how specialized
the expertise and skills are for process optimization in metal forming, metal
joining and metal painting. That's why in many instances the Big 3 company managers gave up on these functions and out sourced the applications to tier one and two
auto and truck manufacturing companies today have so many quality and productivity
issues with painting and welding that they either out source the parts or hire
consultants to take over the processes in their plants.With
this in mind, its ironic that today you can visit the web and see numerous want
adds in which a manufacturing company wants a "multi-skilled" engineer
with expertise in welding painting, press and machining. The reality that management
needs to come to grips with. Engineers are not taught how to control the processes
mentioned. Each of the processes mentioned is unique and can take a life time
MANY BIG THREE EXECUTIVES QUICKLY LEARN WHEN THEY
LACK PROCESS KNOWLEGE IT CAN BE DIFFICULT TO CONTROL MANUFACTURING PROCESSES SUCH
AS PAINTING AND WELDING, YET MANY TIER ONE COMPANIES STILL TRY TO HIRE ENGINEERS
WITH "MULTI-PROCESS EXPERTISE".
naive manufacturing company that looks for the "multi-talented process individual",
typically ends up with an engineer that will have limited expertise in one process,
and his experiences with the other processes was attained as he walked by them
on his way to the coffee machine.
Again we see how the management and
HR perception and expertise can have a great influence on why their plants do
not get the skills, expertise or training necessary for process optimization.
If before you purchased a truck or car you asked to inspect the welds on your vehicle, you likely would not want to purchase that vehicle.
AUTOMOTIVE ROBOT TIG APPLICATION:
weld report deals with the robot TIG auto welding issues.
The parts required approx. 15 precise small tack welds. The tacked parts were
later brazed, The TIG welds were made with a Fanuc Arc Mate 100 robot, and a Lincoln
350 amp "pulsed" square wave power source.
The welding issues
at this tier one part supplier were extensive. For more than a year they had struggled
to attain a production rate of only 40% of what they desired. The tack welds were
frequently missing, arc starts issues were extensive, and the tack weld locations would
leak. After I rectified the problem, I wrote the following report
to the plant management. By the way if you want to automate TIG welds and you have not been to www.tiptigusa.com, you are missing a great process.
THE BIG THREE INSIST THAT THEIR WELDED PARTS
SHOULD ONLY BE WELDED WITH ROBOTS.
ironic that on the one hand we have the major auto / truck companies providing
a logical mandate which insists that arc welds will only be made by robots. On
the other hand, the majority of the companies that use robots will allow "unqualified"
robot operators, programmers or maintenance personnel to daily make "unqualified
weld parameter changes to pre-qualified welded components. And then of course
they will allow unqualified manual welders to make unqualified weld repairs, nice
MANAGEMENT AND WELD PROCESS LIABILITY
today's corporate, automotive manufacturing management, seriously believe that
the weld integrity of the MIG welded components on their cars or trucks should
be left in the hands of inexperienced robot operators?
Does the same management believe that the weld
process is in control when its controlled by unqualified" engineers, maintenance
electricians or the millwrights on the third shift?
Its not a big deal for mangers and supervisors. To attain weld process knowlege can be as
simple as reading and digesting the process books available at this site.
"PEOPLE CONTROL" IS THE MOST CRITICAL
PART OF ROBOT CONTROL:
ironic in the automotive industry that the rare experienced robot programmer who
knows what it takes to manage the arc welding robot line, is rarely allowed to
manage the operators running the robot cells.
may be familiar with this scenario. You have a finely tuned robot, controlled
by an operator or maintenance person who rather than work with the available welding
instructions would rather make their unique unnecessary process changes and play
around with the robot program or settings.
In many manufacturing plants the robot operator or maintenance
person not suited to work with robots, will typically report to a shift or maintenance
supervisor who knows less about weld process controls than the robot operator
does. Lets face it, the prime responsibility of
most supervisors and lead hands in many manufacturing plants that use robots,
is meet the shift production demands and get the just in time parts out of the
Ed. We have had robots for a few years, I don't think my department or manufacturing
managers are aware of all the issues you bring up.
Answer: Ignorance of the resolutions for shop floor weld issues, are the reasons
why so many managers spend a great portion of their time fighting fires without
ever putting out those fires.
Of course process awareness will depend on your companies management
and engineers expertise. It will depend on their ability to see through the weld
smoke, comprehend the weld shop issues and measure the real robot or automated
weld equipment performance potential. Unfortunately at this time too many managers
are happy just to see the robots running. After these mangers arrive home in the
evening, they are so exhausted fighting fires that few of them will visit this
site or review the process control resources.
Weld Fact: Your company does
not have robot weld issues:
the robot weld reject rates are less than two percent every shift.
If the total robot down time, "per robot per shift" is less than twenty
If the weld data or program data set on your robots is so fine tuned its impossible
to increase the robot speed or the weld speed.
your organization has achieved the above then this web site will offer you little.
The weld reality, maybe less than 10% of the global robots are
operating at their peak performance potential.
can set a welding robot to run at 40 to 75% efficiency. Few can optimize the robot
so it can consistently achieve optimum weld quality, with optimum weld productivity
at plus 97% robot efficiency.
Should Run the Robots?
Ed, at our company we normally take production welders and let them run the robots.
Is it necessary to use welders as robot operators, and what is the criteria for
a good robot operator?
. Why use the skills of a manual welder when the robot is designed to provide
the weld skills. When hiring a MIG welding robot operator, it's logical to get a
worker that has a good work ethic. You want a person who will stay at the robot
station, a team player with a good work attitude. You want a person who will follow
process control instructions, a person who will take pride in maintaining their
work area, and take pride in achieving optimum weld quality and production each
The operator should be given basic MIG process training so they
can recognize "what a change in an arc sound means", They should also
receive training on how to inspect a weld, and understand what an acceptable weld
a trainee robot programmer, select an individual that likes working with computers,
CNC or electronic controls. An individual who has an interest in welding. My robot
MIG weld process training book and video is all they need to control the welds,
and the robot companies "robot training program" will do the rest. The
bottom line, an individual requires no weld experience to eventually become a
good welding robot operator.
so many weld issues in auto/ truck plants
Ed, why are so many robot weld issues found in plants that produce auto / truck
Eds Reply. The welding process issues discussed in this site are prevalent
throughout the total welding industry, even in those manufacturing plants that
work with stringent ASME or AWS specifications. However automotive plants deal
with more robots than most other industries and work with high volume applications.
Also it's a sad fact, that for decades in contrast to other metal manufacturing
industries, when it comes to welding the auto /truck industry has been notorious
for not hiring experienced, qualified weld personnel.
/ manufacturing management. It's common in the plants to find the auto managers
tied up with demanding just in time inventory, ISO requirement and spread
sheet issues and those highly unproductive team meetings. Its a sad weld reality that few managers get involved in seeking the root cause of specific
manufacturing and process issues.
UNIONS ALSO HAVE A RESPONSIBLE ROLE IN THE REQUIREMENTS OF WELD PROCESS OPTIMIZATION:
Most union bargaining weld manufacturing rules and regulations were established
at a time when manual weld skills had more meaning than the complex requirements
of robot weld automation and requirements for manual semi automatic best practices and process controls.
automotive industry competes in a highly competitive global manufacturing market.
To remain competitive, a company has to use "when effective", the latest
state of the art, automated welding equipment. In the last decade the weld manufacturing
world has turned a corner, it's become a world in which manual welding skills
are secondary to the unique requirements necessary to optimize "automated welding
equipment". With this in mind the reality is few auto / truck plants few robot
job descriptions are clearly defined.
Correct union job descriptions are absolutely necessary for controlling
automated welding equipment.
management and Inexperienced weld process engineers. There is too much "hands
off engineering" going on in automotive manufacturing plants. An engineer's
role has to be more than the person who gets someone else to provide advice, or
someone who will come to his plant to fix the plant's equipment. Complex automated
equipment needs more than a passing interest from the maintenance department,
it needs the involvement of "hands on engineers" who can optimize both
the equipment and processes critical to the plant.
Automotive double manufacturing standards. Why would any plant manager be tolerant
of manufacturing engineers who allow gaps in the robot welded parts which are
greater than those allowed in the design requirements.
Automotive and weld part design. Few designers of welded parts understand the
weld process requirements for those parts. Designers can have a dramatic impact
on weld cycle and weld quality issues. However to achieve this, they would have
to develop an interest in the weld process used on their parts.
effective weld process controls. Lack of focus by management on establishing and
maintaining effective weld process controls. This has to be a number one management
Automotive and ineffective process training programs. "Our workers are this
corporations greatest asset". This is a common management theme, yet if the
workers are the companies greatest asset shouldn't the quality of the training
provided reflect the importance of that asset? In reality, the weld process training
provided over the last three decades to workers in the metal forming and auto
industry has been either none existent or so poor and ineffective it's had minimal
impact on the weld quality or production.
unique production demands. We need 20% more products each year for 20% less costs.
Poor component weld design, sloppy workmanship, frequent design changes in combination
with poor fixtures, lack of process control expertise, it all takes its toll.
many companies who lack weld process expertise, it can take them twelve to twenty
four months to get the weld production issues resolved for a part with a three
A Weld Reality. If all the robot weld variables
are controlled up front, it should never take more than two days to program and
optimize the robot weld quality and production for the most complex, robot welding
application. Most "automotive" robot MIG applications should require
a few hours to optimize the weld program. For those plants that are taking longer,
the reasons and resolutions are in this site.
HOPE YOUR CHRYSLER SHOCK WELDS ARE OK.
a tier one, USA shock manufacturer could not get the robot welded shock brackets
to qualify for a Chrysler "weld bracket load test" and they contacted Ed to get to the root cause.
load test weld specification required that the robot MIG bracket welds on the shocks absorb
at least a 13,000 lb test load. After welding with
a robot and using the high energy spray transfer mode, the monroe bracket welds
on the 2 to 3mm gage steel shocks would fail typically in the 7000
to 9000 lb range.
was ironic about this application was the Chrysler weld spec for the parts required
a minimum test load of 13,000 pounds on the bracket welds. On evaluating the welds,
it took me two days of manual MIG welding and testing the parts to reveal that
any test load of less than 19,000 lbs indicated a
lack of weld fusion in the shock bracket welds.
reason the Monroe could not meet the test load requirements was;
The robot spray weld deposition was high for the small welds and the resulting "weld speeds were set too high" for the round cold rolled
parts. With weld speeds too fast there was insufficient time for side wall weld fusion,
 The required shock bracket "weld lengths"
were "too small".
After I identified the weld issues I made
the following changes;
Lowered the spray weld parameters,
slightly slowed the weld speed,
changed the gun angles, reduced the fore - hand.
[d] slightly increased the weld lengths by 3 - 4 mm.
the changes the shock bracket welds on average failed at 21,000
lbs. The sligh decrease in the robot weld speed did not impact the weld
production as I compensated with an increase in the robot speeds between the welds.
HOW FAST, HOW SLOW SHOULD A WELDING ROBOT GO?
robots today are under utilized and not welding as fast as they should be. While
other robots are welding at speeds which have a negative impact on the weld integrity.
The robot weld speeds can be influenced by;
[a] the wire size or gas selected,
[b] the shape of the part, the part thickness, or the part surface,
[c] the parameters selected are not optimum,
[d] using pulsed when they should
be using spray.
[e] using short circuit or globular when they should be using
pulsed or spray,
[f] perhaps its the fixture, part design, joint type, part
thickness or ridiculous gaps,
[g] maybe its the weld size and weld length
that could be changed.
my process control books and training CDs
you will find optimum robot weld speeds for all your applications.
WHEN YOU CANNOT GET RID OF THE CRUTCH, THE QUESTION WILL BE WHICH
SHOULD WE USE THIS MONTH?
In their quest resolve weld shop issues, many automotive manufacturing engineers get caught
up with trendy manufacturing methods. The
steel weld manufacturing industry is becoming notorious for it's reliance on confusing,
unnecessary manufacturing practices and standards. These practices will change
as soon as a new author has a book published on a new approach on how to get the
welded parts from the east end of the plant and out the door at the west end.
YOU DON'T ASK THE RIGHT QUESTIONS YOU
CANNOT ADDRESS THE WELD ISSUES.
The manufacturing manger has directed the HR person to look for
a manufacturing engineer to work with the MIG welding robots. The HR requested
that the individual must have experience with some of the following.
HAVE YOU GOT EXPERIENCE WITH THE FOLLOWING?
Dynamic Control Plans.
During the interview no one asks the engineer about
his Weld Process expertise and ability to provide Weld Process Controls for the
robot weld lines.
Welding parts is
not rocket science. The bottom line in most plants steel comes in the rear door and then they;
cut the steel,
[b] clean the steel,
[c] shape the steel,
then weld the steel,
[e] examine and test the welded parts,
and paint the parts,
[g] assemble the final product,
[h] test the final
[I] package and ship the product out of the door at the other
end of the plant.
When working through [a to I],
as a manager responsible for manufacturing, its logical to employ practical individuals
who know how to 'minimize material handling" The individuals will put "practical
equipment" in place that will allow the "highest possible robot weld
duty cycle each shift". The individuals will have the "ability to optimize
the robot performance", and to "train the employees to optimize the
equipment and processes required".
manufacturing companies really need for robot weld process optimization, is to
hire employees with the "necessary process expertise" and make sure
the employees have a good dose of the best manufacturing asset an employee can
have "practical common sense" .
shifts and inconsistent weld results
Ed, we find that with the second or third shifts the robot weld issues often increase.
Many times the operators on these shifts cannot resolve the robot programming
issues. The robot down time and weld rework from these two shifts can be extensive.
How would you address these problems?
Reply. It's typical in many plants, that those with the most programming or process
experience work on the first shift. It's rare to find auto / truck plants which
have highly qualified individuals on all the shifts. The reality therefore in
plants without effective weld process controls, is someone on the second or third
shift is going to get into the robot program to try and rectify a welding issue.
Once in the robot program its easy for someone without in-depth programming or
process expertise to create more robot issues than they are trying to resolve.
lack of in-depth, robot programming expertise is one reason companies should improve
and extend the robot training provided. Also consider the use of custom PLC controls
for simplifying the operation of a robot, so the operator does not have to go
into the complex robot pendant. For example, the robot stops in the middle of
the weld and your robot operator on the second shift has one of the following
robot program options. The operator;
[a] wants the robot to continue from the welding point it stopped,
wants the robot to go on to the next weld,
[c] wants the robot to go to the
[d] wants the robot to go to the home position,
[e] wants the robot to go
to the gun station for a nozzle clean then return to the next weld,
the robot to go to the automatic tool center point for a TCP check and then start
at the next weld,
[g] wants the robot to go to the next part.
the positioner to rotate and start welding the next part.
the above robot program options for the robot operator who does not have the expertise
of the robot programmer, it can get complex. Here is a simple solution. Examine
all the common daily programming issues that could occur for an operator on the
second or third shift. I mentioned eight (a-h). Lets say you find thirty fundamental
robot programming issues. If you do not have a high level of robot programming
expertise on each shift, and you want the robot operators to have more control
of the robot program, you could attain a PLC control, connect the PLC to the robot
control and have the cutomized PLC keys address the primary issues.
With the PLC control, the next time the robot operator has a robot program issue
they likely no longer need the intervention of the highly qualified programmer.
For example, the robot has stopped in the middle of a weld and the operator wants
the robot to go on to the next weld, sometimes a difficult robot command especially
if the robot has to go to another part or the fixture positioner has to move.
The operator walks up to the PLC control and simply presses the PLC [b] key, which
denote robot go to next weld.
Doing it right, is always the quickest way.
Of course when it comes to welded parts, with the high daily production demands in auto / truck plants and the too frequent lack of dimensional controls with stamped parts, the plant
focus is typically placed on weld productivity rather than on the weld quality.
This focus can have a tremendous negative impact on the a shop floor welding culture and will continue to be a liability and recall concern.
All managers should recognize the following fundamental
fact, and hammer it home to all plant welding personnel.
It takes less time to produce a robot welded part that does not require weld
rework, than it does to weld a part that ends up in the scrap or rework pallet.
weld process control training
Ed, what about training, my company spends millions annually on training yet the
extensive weld manufacturing issues seem to never end?
reply: The management approach to weld training and the effectiveness and quality
of the training programs provided are key manufacturing issues. As an example,
I read once that Ford spends over 40 million annually on employee training, yet at one major Ford frame plant, you will find that due to the numerous weld issues, the
robot lines require room for both robots and manual welders. The manual welders are
on the robot line to repair or do the welds the robots miss. The frame parts moving
along the robot line are poorly manufactured and typically have excessive weld gaps or misaligned parts. Both the robot and manual weld data are rarely optimum and the majority of the robot competed frame welds will undergo further
extensive manual weld rework at a later date.
At the same Ford frame plant, the
robot truck frame line moves at a fast pace and with the short time allowed, the manual
welders placed along side the robots were using "oversized poorly suited MIG wires", and using innapropriate weld data and weld techniques for their chewing gum weld fixes. When the frames arrived at the end
of the lines, the majority of the welds are rejected and then the frames are shipped to another part
of the plant for later repairs. The manual welders who work on the robot line are paid overtime
to come in on the weekends to try to repair the frame welds. The reality is the poor manual weld repairs simply add to the weld issues and decrease the total frame integrity. This was and still is a common frame weld
scenario in the Ford plant, and this is the company that is proud of how much it spends on training.
Instead of addressing the part gaps, the
poor weld consumable wire size selection, the inadequate robot weld process settings and
the lack of robot weld best practices and process controls, the misguided manufacturing managers
and engineers at the big three frame plant would daily vent their spleen and threaten
the company that provided robots and the fixtures.
Training "manual workers" will have minimal
impact on the above robot welds problems. The management, engineers and union at this
frame plant will live with these problems till the management takes owneshio and learns how to address
the root cause of all the welding issues.
Its worth repeating. For a management
to solve manufacturing process issues the management and engineers require expertise with the processes utilized. So many "hands of" auto manufacturing
engineers and managers direct their energy at placing blame on sources outside
MIG process control - best practices training is only applicable when welders have time to operate the
weld process in a "controlled manner and have time to make different weld parameter settings for
the different welding problems. When the time is not provided for the welder to
control the process, MIG training will not be affective and management and engineers
should look for other ways to resolve the welding issues. This issue is one of
the prime reasons MIG training at the big three frame plant has not been effective.
weld process control training
TRAINING AND THE AUTO INDUSTRY:
With most robot weld training programs, the prime focus is usually on robot programming with minimal focus on the robot weld best practices - process controls.
In the automotive industry, thin gage robot welded applications with oversize weld gaps create unique
welding requirements, techniques, skills and practices that are not traditional. The gaps found on too many auto - truck parts would
not be accepted in manufacturing plants that are run by professionals who take pride in the parts and welds
It's common to find that when welders come back from a MIG weld training course,
they are frequently taught weld skills they cannot use. Even if the manual skills taught are correct, manual weld skills have
little meaning with the unique requirements with robot welds. Robots require data such as;
 What's the weld speed required for that robot lap weld on 16 gage?
 What weave width and frequency is required for that 6 mm fillet?
 What is the best gun angle for a horizontal fillet?
 The robot does not start at weld number three, change the data.
 The wire burns back to the tip frequently coreect the data.
 The wire ends up with a ball on the end the wire tip, change the data.
welded parts with unacceptable "weld gaps".
Thanks to apathetic manufacturing managers
and engineers, this is the number one problem for "robot" MIG welds.
Management and designer and engineers frequently forget that manual MIG welders
can use "adjustable skills" to compensate for weld gap variations. With
robot welds, it takes sophisticated programming and complex joint sensing controls
to provide solutions to weld gaps.
It's a fact that in most automotive / truck plants, weld part dimension
tolerances are not in accordance with the part design. The acceptable dimensional
weld gap tolerances for optimum, gage MIG robot welds is typically 0.060. This
dimension is acceptable even for thin gage metals up to 0.060. For less than 0.060
the weld gaps should be no larger than the gage thickness. For fillet welds on
parts > 3/16 the tolerance should be no more than 0.010. What is ironic is
the dimensional weld tolerance which are different for the gaps and parts are
rarely known by the designers or manufacturing managers.
To compensate for the common oversize weld gaps
on the thin parts, the automotive manual welder who rarely touches their power
source controls, develops "reactive welding skills." The welder will
dramatically increase the welding wire stick-out to compensate with a weld current
reduction. In contrast the robot can use these practices or utilize needs process data such as weaves or different weld schedules to compensate for
will frequently see "long MIG wire stick outs" (> 25 mm) used in
automotive / truck part plants.
Welders working with thin exhaust parts with excess gaps
will often use a long MIG wire stick out of one to three inches (25 to 75 mm). The reality is that any company that allows manual MIG welders to weld with more
than >25 mm wire stick out, is a company waiting to be sued for poor weld quality.
When welding with long wire stick outs the weld integrity is no longer an issue
as the welds will have more in common with poorly placed chewing gum.
practical solution to welding gaps. Place a little focus on providing training
for manufacturing engineers and supervisors so they can build the stamped welded parts
in accordance with the part design dimension tolerances.
Maybe one day designers of autos will have weld process control - weld best practices training in there University curriculum.
With most automotive welded parts,
the designers weld expertise and weld responsibility frequently ends with him
or her "placing a welding symbol on the blue print". Typically auto - truck
part designers will have no idea of the MIG weld process potential or limitations.
designers ask with the parts they are involved with?
thin can we design the part, so there are no concerns for MIG weld burn-through?
How can we design a part so the robot weld times will be at their fastest?
How can we design a part to ensure minimum weld distortion issues arise? For example How many designers are aware that a robot can produce a 3/16 fillet weld at two
to three times the speed of a 1/4 fillet weld?
How many designers are aware that dramatic improvements in weld quality and beneficial
reductions in weld cycle times are attained by placing one 100mm long weld rather
than two 50mm welds.
it comes to welding for robotics, the designers too frequently don't realize the
impact of their design decisions on the potential weld quality or productivity,
and what should be a major concern to any engineering manager, "they rarely
ask or seem concerned".
IT''S APATHETIC THAT SO FEW DESIGNERS OF STEEL COMPONENTS SHOW AN INTEREST IN THE WELD PROCESSES THAT ARE USED TO JOIN THEIR STEEL PARTS:
How many engineering managers in the auto industry have figured out that designing steel parts that require welds should be carried out by design personnel who at least have some interest in the weld processes - weld transfer mode and consumable that will be utilized.
It used to make me angry when I saw designers at Chrysler - Ford and GM on the way to their office, walk past the weld
production robots and not even glance at their parts in the scrap or rework
bins. Weld part design responsibility should never be considered complete
till all the weld manufacturing and production issues are resolved.
My process control and self teaching resources provide the necessary requirements.
RESPONSIBLE MANAGEMENT KNOW WHERE TO POINT THEIR FINGER
Put the responsibility on the correct shoulders. If
a designer has specified a part tolerance and the manufacturing department does
not meet the dimensional tolerances, then its logical that the management reproach should
be with the design and manufacturing engineers, not with the production personnel
or the robot programmers
America is in short supply of good
robot welding fixture builders.
many robot fixtures have you seen which do not allow optimum MIG gun access or
optimum gun angles?
How many fixtures have you seen that have clamps
that don't hold the parts with sufficient rigidity?
How many fixtures
have you seen in which require a crow bar or hammer to open a clamp.
How many fixtures have you seen that need rework after being in operation for
a few days?
How many fixtures have numerous manual operated clamps when
a simple pneumatic control would open all?
For thin gage welds, you could reduce weld burn
through issues, if the fixture designer would think "heat sink" and
add highly conductive alloys to the clamps and fixture in the weld vicinity. Again
who trains fixture makers in designing to minimize traditional MIG welding issues?
Do weld part designers communicate with the part fixture designers? do both these
individuals communicate with the robot programmers or with person who understand
the weld issues?
A common management influenced issue in many manufacturing
plants, "ineffective communication between all the parties involved in the
robot welding projects"
that can effect robot welds.
size welding wires utilized.
In too many instances,
welders and robots are using MIG wire diameters which are too large
and require too high weld current for the part thickness, weld joint or weld gaps. This is a common problem in automotive
plants, and the bottom line it's a reflection of the lack of weld process expertise from the managers and engineers that made the consumable selections.
robot weld data selected.
The robot weld data is frequently selected
by intergrators and robot programming individuals who lack in-depth MIG weld process control expertise. The weld data while sufficient
to get the robot up and running rarely provides optimum quality or productivity.
Unnecessary equipment bells and whistles,
In 2013, the majority of MIG welding robot cells
are using unecessary,
sophisticated electronic pulsed MIG power sourcesl. This equipment is typically
recommended by salesmen and purchased by people who believe in salesmen. Less
than two percent of MIG welds will require expensive and complex pulsed welding
equipment. The prime reason this unnecessary welding equipment is purchased, the
purchaser is frequently over optimistic that more costly equipment will compensate
for a plants general lack of manufacturing controls and MIG process expertise.
Innapropriate weld responsibility:
Its too easy in the auto industry to find management that places the responsibility for the robots
and weld process controls with mechanical or electrical engineers, These are engineers who
typically have never struck a MIG arc and lack weld process control expertise. If the individual responsible cannot
operate a process and equipment at it's highest efficiency potential, then they
should not manage it till they receive adequate training.
The same management
will not think twice about allowing the maintenance electricians and millrights to make weld process changes which
negatively effect the weld quality or productivity. This is a plant which is ignorant
to the product liability consequences of inconsistent weld quality. Maintenance
should be in on Saturday and Sunday doing preventive PM. They should not be allowed
to make any "unqualified inexperienced process changes" which can negatively affect the so called pre-qualified weld data.
If maintenance have to make changes, the management solution is simple, ensure these
individuals have effective
MIG best practices - process control training.
Management often believes that the best bang for the training buck
is train the workers on the shop floor to respond and resolve the numerous weld
quality and production issues.
I believe the training should be directed at "preventing" those issues from occuring.
ONLY A GM TRUCK WELDING ISSUE, SO WHY
WOULD THE MANAGEMENT GIVE A DAM?
a tier one Canadian plant, (AG Simpson) which made bumpers for GM trucks, I was asked by the
management to resolve some robot MIG weld issues which were causing costly rejection
WAS THE TAIL WAGGING THE DOG? When I got to the plant I was asked by the management to first
get the union rep's blessing to work with the robots and robot personnel. I have to admit at this
point I started to wonder who I should invoice for my consulting services, the
plant union rep or the management.
I quickly resolved the robot bumper spatter weld
problems, then arranged a training program which would ensure the welding issues
would not be repeated. To ensure all three shifts received the process training, I
provided the training over a four day period. Now keep in mind, the welding problem
at this tier one supplier was a major concern for General Motors. a small company located in Detroit, yet In the four days I provided
the training not one of the plants managers or one of the plants engineers attended
the MIG process control training, yes they were invited several times.
Two major management
issues need addressing at this plant,
 Management needs to get back control
of the shop floor.
 Management needs give itself a kick in the rear and send a strong message to its engineers
about their lack of process expertise and manufacturing responsibilities.
Weld Calibration: Are the
robots in your plant calibrated? The majority of the robots sold before 2000 were
never calibrated. Few robot manufacturers or integrators bothered or were aware of the necessity
of determining if the weld data in the robot welding program correlates with the
real weld data used on the welds. You cannot create uniform manufacturing practices and weld process controls in a plant in this situation
. If the measure robot wire feed rate is 600 in./min but the robot pendant data
shows 700 in./min, process controls become a joke, If you put in 200 amps on the pendant and get 150 amp at the weld whats the point. If one Panasonic robot has the wire feed set at 350 IPM and delivers 200 amps and the other Panasonic robt welding the same parts has it's wire feed set at 350 IPM delivering 175 amps, well thats simply bull shit.
Few Global Arc Welding Robots Have Correct Calibration.
Many robots are poorly calibrated. Program 29 volts into
the robot pendant, out pops 25 volts from the power source. Program a wire feed
speed of 400 in./min in the robot pendant, and the real measured wire feed speed
is 300 in./min. Program 300 amps in the robot pendant and the power source provides
IT'S IMPOSSIBLE TO IMPLEMENT EFFECTIVE WELD PROCESS CONTROLS
WITHOUT CALIBRATION OF THE WELD PARAMETERS USED FOR THE WELDS. HOWEVER AS FEW COMPANIES
ESTABLISH ROBOT WELD PROCESS CONTROLS, CALIBRATION IS NOT REALLY AN ISSUE.
THE TIME TO DEMAND CALIBRATION IS IN A PARAGRAPH WRITTEN INTO THE PURCHASE CONTRACT FOR THE ROBOTS. FOR THOSE THAT FORGOT TO ASK THE INTERGRATORS TO CALIBRATE THE ROBOTS AND NOW HAVE THOSE UNCLAIBRATED ROBOTS SITTING ON THEIR WELD DHOP FLOOR SHOULD DO THE FOLLOWING
CONTACT YOUR ROBOT SUPPLIER
AND TELL THEM THE ROBOT INSTALLATION IS NOT COMPLETE TILL THE DATA IN THE ROBOT
PENDANT (WIRE FEED, CURRENT AND VOLTAGE) AND THE WELDING POWER SOURCE ARE CALIBRATED.
IN YOUR WELD SHOP, DO YOU HAVE A
WELD MANAGER OR FIREMAN?
NEVER ENDING WELD SHOP FIRES :
automotive and other high volume production plants involved with arc welding robots,
Its not uncommon to find that extensive energy, time and resources is lost each
shift trying to put out the weld production fires.
managers and engineers involved with welding and robots may feel more comfortable,
using their time and resources to deal with the daily manufacturing fires, rather
than face the reality that to quench the weld shop fires they might have to learn
about a welding process or piece of equipment which is critical to their organization.
Ed's Robot Weld Process Control Resources
have the answers to your robot isues.
LASERS AND WELD TRACKING?
IF YOU KNOW HOW TO JOIN TWO PIECES OF METAL, THERE
ARE FEW AUTO APPLICATIONS THAT WILL BENEFIT FROM LASER WELDS OR LASER TRACKING SYSTEMS.
In the automotive
industry, money for manufacturing equipment sometimes appears to come from a bottomless
pit. In this environment it's not difficult to understand why every conceivable
bell and whistle is pushed by those selling the weld, laser and robot equipment.
Also its easy to comprehend why unnecessary, costly equipment is purchased by
those who believe that the more money you spend the less weld problems you will
have in the robot cell.
remember at a Ford truck plant in Detroit, that with the purchase of a multi-million
million dollar robot line they also purchased every possible robot option including
a costly laser weld vision system for each robot. The engineers figured they needed
the laser tracking systems becasue they were not qualified to control the dimensions
of the parts provided to the robots. Within twelve weeks all the lasers were removed
(costing > $300.000.00). The high tech lasers were dumped in cardboard boxes
and today they are still likely gathering dust in the plant's store room.
The reason the lasers were dumped, no one in the plant could handle the highly
technical issues that were derived when problems or corrections were generated
by the lasers.
Good parts, good fixtures, good weld data, good process
controls, through arc tracking, TCP controls, trained personnel and knowledgeable
managers and engineers, these are the keys to weld automation.
Professional Approach to Weld Process Control.
For consistent, optimum weld productivity and quality visit.
training resources. These unique easy to learn weld process best practice and process control resources are not provided at any global universities that provide weld engineering programs.
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