Robotic Mig Welding vs Manual Mig welding

By Larry Adamski Date 05-07-2008 12:39

I am new to this forum. I've tried to search on the above topic and for some reason the forum search didn't reply. Thus, I apologize if this has been captured before. I was wondering what benefits there are, if any, using a robot to mig weld versus having a man/woman weld. I'll assume right off the bat the the robot programmer is highly qualified and that he is supported by an experieneced weld expert. What I'm curious about is if the robot is any faster and if the robot has a higher level of quality versus welding manually. What I mean by faster is that the robot doesn't get tired or need to use the bathroom, eat lunch, or make a phone call. I'm sure someone has compared the efficieny of a robot versus a man/woman. I need to find this documentation. I am looking to make a business case of robot versus manual. Thanks for any help in my quest. I will mainly be welding mild steel tubing. Wall thicknesses anywhere from 1/8" to 1/8" or 1/2" 1/2" or anywhere in between.

By MDG Custom Weld (***)

Date 05-07-2008 13:12

Robotic welding is usually 2-3x faster, but it has many challenges to deal with. First and foremost is the part quality and fit-up, and the fixturing that is used. Second is having a qualified programmer that has a good knowledge of welding. We use 50ipm as our target welding speed for all robotic applications, and we achieve that 80% of the time. When compared to manual speed of 20ipm max, it's considerably faster. The part fit-up becomes important since most newer robots maintain an accuracy of +/- .010 depending on size and make, and they go where you program them to go, so if your parts are +/- .100 then it's possible the robot welding results will be inconsistent compared to the manual person that can make changes on the fly. Many companies think just adding a robot will take them to the next level in productivity, but these other factors need to be taken to the next level as well to achieve robotic welding success. Square tubing with consistent fit-up should be easy to automate. While your comments are true about the robot not going to the john or eating lunch, you still need a person to load and unload the robot fixtures unless you automate that too.

By js55

Date 05-07-2008 13:23

In order to really take advantage of robotics I think you need two primary things, the ability to acquire parts with low tolerances, as MDG stated, and repeatability of welding applications. Without both of these your programs will proliferate beyond manageability, and you'll spend more time programming than welding.
There are some vision systems available intended to alleviate tolerance problems, and granterd its been awhile since I've reviewed the technology, but they are very expensive and IMO not quite ready.
The other thing is you need to think in terms of an entire systemic application. Its difficult if not impossible to slowly adapt a manufacturing environment over to robotics.

By DaveBoyer (*****)

Date 05-08-2008 03:58

   As the others have stated repeatability in fixturing and acuracy of parts is everything.

   In the late '80s and early '90s I worked in an automobile frame manufacturing plant that was trying to convert some material handling and welding operations to robotics. In these large and awquard parts concistancy was an issue without a good solution. In the end a robot welded 1 side of an assembly and a person the other. The fixturing provided a reasonably consistant joint condition on the robotic side, while a person dealt with all the inconsistancy on the other side.

   In the right high volume situations a robotic operation will work well, but in other situations might not work at all. So much depends on the parts being welded.