Tech Tuesday: Creating The Perfect Grip
In today’s installment of Tech Tuesday, we take a closer look at the Axe Bat’s distinguishing feature: the knob and handle.
This is where everything starts. It’s the source of the Axe Bat’s many performance advantages, and what allows batters to achieve greater power transfer, bat control and barrel acceleration. It’s what makes the Axe Bat safer; the axe-shaped design lessens the risk of hand and nerve injuries and reduces hand fatigue. And it’s what will enable the next major industry innovation in bat design and barrel construction — one-sided hitting (more on that later).
Joining us, as always, for Tech Tuesday is Hugh Tompkins, Baden’s Director of Research & Development.
Q: When did you first see the Axe Bat knob/handle?
A: When I started at Baden. That was January 2012. At that point, we had several different versions of the Axe Bat knob. They were all very different and none of them had been truly tested in the field.
Q: What did the original knob and handle look like?
A: The first knob we had was huge. It was very sharp on the edges — like a pointy oval. It flared on the backside almost as much as it flared forward, and it was really big. One of my first tasks at Baden was to work on the Axe Bat. I knew we needed to make some changes.
Q: Did you get specific instructions on what to change? Or was that left to you to determine?
A: I didn’t get anything specific. It was more like, talk to Larry (Carlson), who is an engineer we have working on the project, find out what he’s doing and go from there. At that point, (product manager) Brent Weidenbach wandered into my office. He was very into the Axe Bat and had his own ideas for what it was lacking and what it needed. The first thing he said to me was, “We need to fix the knob.” I said, okay, we can do that, and we laid out a process. Brent very much became my partner in this from Day 1.
Q: What was the first step?
A: The first thing we did was shorten the development cycle by doing rapid prototypes instead of full-blown manufacturing molds. We started by modeling a new handle on my computer with Brent standing over my shoulder, talking about what he thought needed to change. I also looked at the knob we’d been using and took a lot of measurements. Basically, we created a new model from the ground up to be tested.
Q: After the computer model, what was your next step?
A: We used a local company to print a 3D model using a rapid prototyping process. I then took that 3D model, which was made from corn starch, and made a silicone mold. We clasped that mold to the end of a bat and poured in quick-casting resin. That basically molded the shape to the handle. So when we took off the silicone mold, we had a bat with a hard plastic knob in the shape of what we’d designed on the computer.
Q: Was that plastic piece strong enough to hit with?
A: Not always. In the beginning, we tried a lot of different ways of attaching our prototypes to the bat and not all of them were successful. We knew we had to be able to hit with each version. That was key to the process. We couldn’t just have something you squeezed or held in your hand. It had to be on a bat we could hit at speeds.
Q: Who tested the first versions of the knobs/handles you created?
A: At first, Brent was my primary bat tester. We needed to have a lot of iterations and a lot of quick cycles. Brent had played at a high level. He played in college and was a very sound, mechanical hitter. So he was a good guy to do development with. We also had a few guys in the office who were baseball players that we tested early versions with. That expanded to outside players and teams as we went.
Q: After you got player feedback on a design, how long did it take you to implement changes and create a new version?
A: About three days, start to finish. It took about a day to make changes on the computer, then another day to print the rapid prototype and get it back from that local company. Then, it’d be another day or so to make the silicone mold and do the casting.
Q: What other research did you do outside of the field tests and rapid prototyping?
A: We looked at a lot of scientific papers, outside research and even shapes of axes that had been used historically. We experimented. We tried anything we thought might improve it. We even tried one handle that looked like a ball joint on the back. So it was a lot of trial and error. By doing this experimentation, we learned what the different geometric features of the handle do to the baseball swing. That helped us find the perfect “Goldilocks” dimensions for what you see today.
Q: What were some of the stranger things you came across in your research?
A: At one point, we were reading a lot of hand studies. We found one that had been done for either the ice industry, or the meat industry…at any rate, it was for guys using hooks to hoist heavy objects. The authors had looked at a bunch of different handles to figure out which one gave the most arm fatigue. They’d used cadavers in the study. They’d take a cadaver’s arm, cut open the forearm and tug on the tendons that articulate the fingers. Using force meters on the fingers, they could pull on the tendons and measure how much force was needed to grip different shapes.
Q: Did you learn anything from that?
A: Yeah, that study actually supported our oval concept for the knob because it reinforced the importance of the pinky and ring finger as the “power hooks” of the grip. We open those two fingers up more with our oval shape, and that allows them to contribute more to the grip force than they would if they were gripping a straight cylinder, such as a traditional baseball bat.
Q: How many different iterations did you go through between the knob you started with and what we have today?
A: I don’t know the exact number of prototypes we made and cast on a bat. But I know it’s somewhere around 14 different versions we went through — some of the prototypes broke during testing.
Q: How did the actual shape of the knob change? Where did you start?
A: The backside was first — we started reducing the flare. Eventually, we got it very flush back there. That increased the handle’s contact surface area without introducing stress riser points. A round knob, for instance, has a localized crushing point at the bottom of the palm.
Q: What came next?
A: The angle. We changed the angle of the knob to make it steeper. Now, it’s about 22 degrees. The reason we did that was because with the old version, the bottom of the knob was still in the meat of your palm. And we wanted to get that below your hand.
Q: What were some of the other changes?
A: The other major improvement we made was to the width of the knob. If you look at the first knob from the bottom, you’ll see it has a big front hook and is shaped like an oval. The current knob looks more like a flattened egg or a mushroom. We did that to better support the perpendicular forces affecting the bottom hoop of your hand. Whereas the first version hooked under your pinky, today’s version has a shelf supporting more like 140 degrees of the hoop your hand makes when you close it.
Q: Do you use the same knob/handle across your entire line of Axe Bats?
A: No. Our slow pitch softball and Tee-ball handles and knobs are different. For slow pitch, we made the knob thinner and shortened the oval portion of the handle to accommodate unorthodox grips common to that game. For Tee-ball, it’s not an exactly scaled-down version, but it is smaller because it’s made for children; the critical angles are proportionately the same.
Q: Do you plan on making more changes to the knob/handle, or are you done?
A: We’re always innovating and tweaking. That’s the nature of my job. But we feel great about where we’re at with the current handle and knob and don’t envision making major changes soon.