Simulation at Work: Benchmade Knife Company

Simulation at Work: Benchmade Knife Company

We’ve written about Benchmade Knife Company on this blog in the past. The company uses PTC solutions to design the knives and safety tools that hobbyists, military, and emergency responders rely on in the field. But let’s look a little closer at why a company like Benchmade might use PTC simulation solutions.

More Mechanisms

From an engineering perspective, the company has an intriguing assortment of mechanisms at the heart of its knife catalog. In fact, there are nearly a dozen different systems to choose from—some patented and exclusive to the company, and some based on designs that go back more than 1000 years!

Here are a couple examples of mechanisms from the catalog:

AXIS® A 100-percent ambidextrous design, AXIS® gets its function from a small, hardened steel bar which rides forward and back in a slot machined into both steel liners. The bar extends to both sides of the knife, spans the liners, and is positioned over the rear of the blade. It engages a ramped, tang (the projection on the blade by which the blade is held firmly in the handle)portion of the knife blade when it is opened. Two omega style springs, one on each liner, give the locking bar its inertia to engage the knife tang. As a result, the tang is wedged solidly between a sizable stop pin and the AXIS® bar itself.

benchmade-levitator-model1

LEVITATOR® The knife handle scale/liner is cut to create a spring system which is used to leverage a lock-pin in and out of a notch in the tang of the blade. This spring/pin system effectively locks the blade both in the open and closed positions.

Why does any company need so many ways to open and close a knife? Simple: User requirements and user preferences.

More Options for Customers

Some mechanism designs are simple, to keep manufacturing costs low. But often, those require two hands to close, so Benchmade also offers more sophisticated mechanisms that allow the user to snap the blade shut safely with just one hand. Still other mechanisms prioritize strength. And so on. That way, customers can decide which tradeoffs to make: cost versus utility versus ease of use versus strength.

Of course, all those mechanisms need to be tested for clearances, etc. But before we talk about that, there’s more to consider than the moving parts. Handles and liners change from model to model too.

“Handles and liners come in all different shapes, sizes, and materials,” reads the company website. “Benchmade takes care to design enough grip and stability in each model no matter the overall size so that it will ultimately be functional to a broader range of varying hands.”

Then the knife blades themselves can be made of different steels with different coatings and hardness as well.

And you’re almost right. In fact, the company catalog includes 120 knifes and safety tools. As you would expect, and perhaps even fear, every one of those designs has to be tested before it goes out the door, and preferably before it goes to manufacturing.

And you’re almost right. In fact, the company catalog includes 120 knifes and safety tools. As you would expect, and perhaps even fear, every one of those designs has to be tested before it goes out the door, and preferably before it goes to manufacturing.

Fortunately, Benchmade uses PTC simulation software.

More Options for Engineers

With PTC Creo Mechanism Dynamics Extension, engineers digitally test clearances for the knife closures. The PTC add-on allows engineers to simulate the forces and accelerations in systems with moving components. They can even adjust performance by adding springs, friction, and gravity. Heck, the software would even allow them to test knife mechanisms driven by a motor if they wanted.

The team at Benchmade also uses PTC Creo Simulate to test the strength of the designs. Engineers use the tool to test structural and thermal properties, well before physical prototyping.

With both these simulation tools, engineering gains early product insight and improves verification.  They can quickly try new ideas, test them, and then optimize designs. So they have more flexibility and gain confidence in their work before sending it downstream. Best of all, PTC simulation saves time and money since it reduces physical models and leads to fewer and fewer design iterations.

Here’s one example of the results: 615 pounds of torque, more than ½ inch of deflection, and the steel fractures while the lock holds strong. Watch Peter and Tracy from Benchmade Knife Company put the new 300SN AXIS Flipper through a grueling lock strength test.

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