Welding & Painting

Welding is a very skilled and rewarding profession but it can be a very dangerous one due to the toxic chemicals and flammable oxygen, high heat and sparks involved.

Robot welding machines have been around for many years and many of us probably first saw them in the auto industry’s assembly lines.

They are usually very heavy 1000+ pound robots kept in one place on a stand or in an enclosed small space called a cell and once they are programmed the operator does not have be beside it for the most part.

Welding and painting robots usually have one big arm with a replaceable end effector for either a welding torch or spray painting gun.

This type of industrial robot is called an articulated robot or 6 axis robot. (other kinds are cartesian, SCARA, delta, orbital, collaborative..).

A typical articulated spot welding robot has the 6 axis with 3 rigid members connected by 2 revolute joints and they are mounted on a rotating base.

Now these robot arms can be purchased brand new but many of the large companies sell fully reburbished used units since new prices could run upwards of $30,000.

So some reasons why a company would purchase a welding robot other than for safety would be for accuracy, efficiency and cost savings.

Every weld would be identical and this is difficult for a human operator if you need to do hundreds of repetitive welds per hour.

Robot welders would be efficient and of course there could be cost savings as with most robots and a reduction in time to do each repetitive weld.

Now of course robots have been replacing people on the assembly lines in many job types for years and there is an argument to be made for whether this should be done or not. Certainly it has a place where the welding is dangerous and overly repetitive.

Welders will still have jobs in custom shops and smaller shops because there are many things that need to be welded that can’t be taken to a robot shop.

What would a typical robot welder look like?

A 6 foot tall robot would have the large articulating arm, some power source, a spool of wire for welding and a removable torch at the end as well as various safety mechanisms like an arc shield.

The operator would train or program the robot to perform certain welding maneouvers using the control unit. Usually a device called a teach pendant is used to train or program an industrial robot.

Now the types of welding that can be done with the robot are the conventional types like spot welding, gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), plasma welding etc.

Painting robots are available as well and of course the dangers from fires are much less but there still is the issue of toxicity of the paint.

Of course every robot will have safety kill switches and ways to recover if the arm was to jam or break for some reason.

There are moves towards using collaborative robots for welding and painting where the operator would not have to spend time pre-programming the moves required but would be working along with the robot more like in real time.