Why are production knives still sharpened by hand?

[blame it on god]

I agree 110%. Watch the benchmade factory tour vids, and they use some sort of crazy laser scanner to check their sharpening. They even explain why they don't use automatic sharpening machines. In a factory where they produce many different models, its easy for a human to switch from blade to blade than it is to tear down and re set up a machine. Much, much more cost effective.

The laser must have been broken the days my Adamas and a few other BM's were sharpened.

No human can match the speed and efficiency of a robot....EVER. As far as switching from model to model it's a matter of calling up a different program and changing a gripper after the initial set up.

 

[kornphlake]

The laser must have been broken the days my Adamas and a few other BM's were sharpened.

No human can match the speed and efficiency of a robot....EVER. As far as switching from model to model it's a matter of calling up a different program and changing a gripper after the initial set up.

Robots are very efficient doing jobs that are highly repeatable, however they fail miserably when the work is not where it is supposed to be. I used to program welding robots, robotic welding is great for simple jobs where there aren't too many pieces that stack up or parts with multiple bends, with these jobs the work is in the same place or within an acceptable tolerance every time parts are loaded on the fixture. There were some jobs that just weren't practical to weld on a robot, the operator would have to adjust points on every single part to get a good weld. Programming for variation is very difficult, touch sensing and arc sensing technologies have made it somewhat feasible to automate jobs with inherent variation, but there are still limits to how much variation can be automagically corrected in the program. I've never tried to program a robot to sharpen a knife but I have spoken with others who have, my understanding is that blade shapes are not consistent enough to make sharpening on a robot as simple as calling up a program and changing a gripper, due to the variation from part to part nearly every blade would need a unique program, I'm not talking about each blade model, I'm talking about each individual blade. A robot is accurate to a few thousandths of an inch depending on the quality of a robot, to grind a blade to an edge a few atoms wide using a robot is like using a sledge hammer to crack a peanut, it's faster and less expensive to hand sharpen.

 

[FlaMtnBkr]

What happens when the edge is a little off center? There is something called tolerances and if it is within a set parameter it is OK, but it isn't in the same exact spot every time. As some of you know, and are complaining about, sharpening isn't the easiest task. A machine would have to know where the very edge is as well as the exact center line which will change with each blade. Assuming it got it right, there are still burrs and wire edges to deal with. And how will it know it is Sharp enough? If it isn't, how much blade will be ground off trying to get it Sharp. It isn't an easy operation and I can imagine a whole factory full of machines just to sharpen and make sure it is to an acceptable level of sharp. And each machine would have to be changed when a different blade shape comes along.

Compared to a worker that can pick up whatever blade that is placed in front of him and sharpen it, buff the edge, and test it and then on to the next. Which might be the same or it might be a completely different model. A trained worker would be much quicker, cheaper, and efficient than the machinery required.

 

[jdm61]

But the CATRA machines, which are essentially "hand" sharpening are reasonably priced and more efficient than an edge pro, and would probably be better than a belt edge.

I'm sure plenty will disagree, but hand sharpening is faster, cheaper and more consistant than using a machine. The real reason may be that they already have old belt grinder and buffer stand setups for polishing, etc in a lot of these factories and they need to use them for something.

I've been in the Benchmade, Kershaw, and Gerber factories and spoken with engineers in each of these factories about why they haven't automated sharpening. The short answer is that the ROI is much longer than 5 years and the resulting blade isn't significantly better than a hand sharpened blade. Based on the information I've collected the processes that shape the blade before it can be sharpened are not repeatable enough to make fully automated sharpening possible, you'd end up with off center edges, inconsistant edge bevels and poorly sharpened blades. Leatherman uses a robot to sharpen some of their blades and their edge consistancy and sharpness are worse than the blades that are sharpened by hand.

The edge pro, wicked edge, and other guided sharpening systems are not nearly efficient enough for high volume production work, especially for setting the bevel on a factory un-sharpened blade, automating a system like the edge pro isn't as simple as hooking it up to a pneumatic cylinder or servo drive. When you use a guided system you are still using human tactile feedback and human response, which is difficult to reproduce electro-mechanically, even in 2013.

 

[dkb45]

How about by the high sellers (stuff like a Grip) get the machine sharpening and the rest get hand sharpened. Few knives needing to be hand sharpened means the workers can take a little longer and yield better results.

 

[bpeezer]

The companies can probably save more time by upgrading other manufacturing processes. Like was stated earlier, an ROI of 5 years for this kind of investment usually isn't ideal.