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GPS Systems for Assembly
Ask the Expert – 5S: What to Do

GPS Systems for Assembly

Quality has a number of warranty claims for loose bolts, or better yet, you are trying to be pro-active and ensure your bolts are tightened correctly and seated in position. Great idea! Now what?

We offer high quality poke yoke dc electric tools, Bluetooth poke yoke and air poke yoke tools, transducerized and signal torque wrenches. You name it, we have it, or it’s available somewhere in the market with fancy torque, yield or gradient algorithms with special 24v inputs and outputs (I/O) which can start and stop the line on a NOK RED light. After all that, we still can’t tell you which bolt was bad…even though it does a great job of controlling the assembly process, as well as provide (in some cases) statistical data to ensure the parts are fastener correctly.

Quality still get requests to ensure that every bolt was tightened so customers have to spend more on elaborate PLC’s with prox sensors or cameras.

Prox sensors allow you to follow a bolt pattern and enable and disable a tool when the sensors are met. But this tends to be unstable and we always see where operators have placed a bolt right near the tool that simulates the part on the assembly and they just run it down whatever amount of times they need to, (oh- sorry, that never happens does it..) so the plc has counted the right amount of screws. Nice! We have installed more elaborate camera systems to ensure all the bolts are seated as well as check for other criteria on the part but we still need a precise lighting environment to ensure accuracy of the read. Also, maintenance is constantly being called back and forth to adjust the light sensors to make the cameras work and we still need a PLC.

We made some progress when we added torque arms with encoders on them. They work well, ensure you follow a bolt pattern, and provide a LED screen to follow your assembly and the tool doesn’t work unless you are on the bolt itself. They don’t need a PLC and are relatively cost effective. Not to mention they absorb the torque kick experienced in high torque applications. What can be an issue is these arms have to be over-designed to ensure rigidity at the joints where the encoders are. If they weaken here, the arm loses position and bolt patterns will not be recognized and followed. Replacing the arm and encoders is usually required at this point but not always. Big and bulky solves some problems but creates others. The only problem here is manufacturers are bring forced to build lighter, more eco-friendly parts or critical areas like airbags, seat belts and service areas, require one person to move a tool into many different locations. The restricted movement of the torque arms can also slow the cycle time down as you have to follow the path of the arm not the path of the part. This problem makes the use of a torque arm, particularly with encoders, very difficult to manoeuvre in these small areas. So what do you do??

We have all thought of it – the kids with Nintendo and Wii have these cool little wands that magically follow the screen – hey why can’t we do that?? Well, the simple answer is that your not 16- and you don’t have 5 million dollars to invest in the technology.

Remember, they have volumes of game sales (millions) we have 200 applications which makes it difficult to get the price down to something reasonable. There are camera-based systems, but if you cover the camera or contact pads in any way you loose position.

See product spotlight for the local GPS systems from WSP technologies. A triangulated positional sensor mounted on the tool and within 15 feet of the satellite position sensors or “grid” work together to detect and track tool position.

Not camera-based, and completely stand alone, a PLC is NOT required to interact with the system. We can even attach bar codes to the output data from the “poke-yoke” tool.

Even the most highly sophisticated tool algorithms evaluated, at the end of the day, cannot tell you which bolt was fastened so they need some help – help from above.

Now with 3D positional control systems, we can install the robust sensor anywhere on the tool within some line-of-sight to the grid, input your part picture on the screen and watch the tool move to the bolt, and not just any bolt- but your selected, fully programmable bolt pattern. OK/NOK lights and attached statistical data and barcodes work together for total traceability.

Now; Finally, we can combine the accuracy of the poke yoke tools with positional control and without a PLC! – Even if you use extensions to get into compact areas, the programmed sensors compensate for the length – STAR WARS for the assembly line! You can even attach the sensor to an existing torque arm to track the tool position. You can easily move the sensor to another station when you’re finished with a short run project. Typical applications are air-bags, brake lines, seat belts, cylinder heads, engines, aircraft assemblies and electronics such as cell phones – to name a few.

It solves so many common problems we see in today’s manufacturing. But there was no current way to help without a lot of expense and electronics.

You always need expertise during quoting and implementation, and as always, that can be found at Core Tool Technologies!

Ask the Expert – 5S: What to Do

Companies have applied 5S and typically regard it as a process unto itself.

The term 5S is derived from five Japanese words that describe a process to organize the workplace. A rough translation into English generally is, 5S: “a place for everything and everything in its place.”

Most people, when they are asked the purpose of 5S, cite safety, discipline, employee morale, and reduced waste of motion.

To cut to the chase, the true purpose of 5S is to spot problems quickly.

The biggest issue is sustaining 5S. Supporting staff must have all the tools they need to sustain, self-audit and continuously improve the 5S program. The missing element is often the simple requirements of management. If someone doesn’t follow a formal policy for safety, doesn’t come to work on time, or doesn’t do an assigned task as specified, there are consequences. Whether those consequences consist of coaching, discipline or even firing, it is simply not OK to ignore the standards and the process fails without everybody’s commitment.

It’s 5S without all the “S”…