CNC Dental Tooling: Hammer Head Suction Mirror
On the front lines as licensed dental hygienist in Washington State, Lee Emmons knows firsthand that necessity is the mother of invention. Forming EMS Dental Designs, Emmons is the inventor and patent owner of the Hammer HeadÂ® suction mirror, a Class I medical device used to remove water and debris out of the oral cavity while providing over 180 degrees of visibility.
With the help of a Tormach PCNC 770, Emmons has quickly ramped up manufacturing of the Hammer Head in less than one yearsâ€™ time. â€śLast year, I went from building prototypes and bending copper tubing around mirrors to drilling holes just with a Dremel,â€ť Emmons recounts. â€śI purchased a TormachÂ PCNC 770 last February and learned how to run a mill, 3D model in CAD, and create machine code with SprutCAM. I had to stay pretty focused on exactly on what it was I was doing.â€ť
With the exception of a rhodium-coated mirror coin held at the front of the housing, Emmons manufactures the Hammer Head entirely on his PCNC 770. â€śI make the entire housing that holds the mirror coin. The coin clicks in place and is held in position with a cross piece of stainless steel used to hold tension on the forward edge of the housing. Because itâ€™s a front-surface mirror, you can replace it with another when it gets scratched up,â€ť he explained.
Emmons hasnâ€™t let his relative inexperience in machining get in the way of his product development on his first-ever CNC project. â€śOne complication with this project was that I had to flip the stainless bar over and upside down to mill out the backside. I also had the challenge of milling out the front size at a specific 32 degree angle,â€ť he said.
In total, Emmons, mills eight housing components out of a single piece of stainless steel flat bar to make each Hammer Head.Â â€śAfter I finish cutting out the bottom, I remove the bar from the fixture plate and put it onto an angle plate in order to mill out the stem end of the suction mirror head. Then I flip it down onto another fixture to plate to mill out the inside of the head into what I call the serpentine shape.â€ť
He also uses an undercutting technique to bore out the inner diameter.Â Emmons explains, â€śI just initially start out with a hole in the middle and then I just open that hole up with regular end mills. Then what I do is use a key cutter and drop it down inside to cut out the inside and there are some pretty interesting shapes in doing that. The little shelves that hold the mirror need be exact and thereâ€™s another level I have to open up within a couple thousands thick.â€ť To produce the handles, Emmons uses hisÂ PCNC 770 as a vertical lathe, threading the ends and also cutting a criss-cross grip pattern into the handle surface.
With such careful attention to detail and superior design, Emmons has improved upon the tools available for ultrasonic dental procedures. â€śThe super thing about the Hammer Head device is its suction capacity. To measure suction volumes, I had to build a special testing device that is almost like a little wind tunnel. Because dental equipment using suction systems vary in flow and strength, I had to take that into consideration when designing the Hammer Head. My goal was to be able to maximize the device to the optimum capability available. This meant that everything had to be made ultra thin and it had to be bored out with as large of an inner diameter as possible.â€ť
â€śThe clinicians that have adopted and are using the Hammer Head in practice have been realizing it has been cutting their time in half and has been increasing their accuracy,â€ť Emmons said. â€śWhen youâ€™re getting your teeth cleaned there are certain areas in the mouth that we canâ€™t see. So, at some point hygienists and dentist are guessing and missing quite a bit. The Hammer Head has extended the visibility into the oral cavity and lets us work more accurately without drowning the patient.â€ť
With the Hammer Head successfully implemented in a number of dental offices and dental schools, Emmons has made the devices available for purchase on his website. His future plans include manufacturing the Hammer Head out of aluminum and then have them hard anodized.Â To do so, Emmons is concurrently improving his machinist skills, increasing production, and optimizing his toolpaths.
â€śI will re-write the CAM file and then go out and watch the machine work, taking notes as the machine is running and keep trimming my program down further and further to be able to optimize my time and machine time,â€ť he added. â€śIâ€™m still figuring out how fast I can run things. At first I was running fairly slowly, but now Iâ€™m switching from stainless steel to aluminum and Iâ€™m realizing I can really crank things up.â€ť
Using the Hammer Head and his past year as a way to encourage others to learn CNC and build a product that solves a real-world design challenge, Emmons ends with this advice, â€śMachining is something I had to learn last year and I realize you could spend an entire lifetime just learning that. Iâ€™m sure there are ways I can improve my productivity and I know that comes with time. But if a guy from the dental field can machine a part on a CNC mill, anyone can do itâ€”you just need to have the desire to put your mind to the challenge.â€ť