Miniscule medical part machining

For surgeons and dentists, finding and fixing ailments in odd, difficult places – deep inside the mouth, under layers of skin, or in an eye socket – can be challenging. Magnification and illumination help them see, but manufacturing microscopic products can be as challenging to the companies making vision devices as it is for the medical professional trying to work without them.

Designs for Vision Inc. in Ronkonkoma, New York, designs, manufactures, and distributes these medical devices and the instruments that go with them. Founded more than 70 years ago, the company specializes in custom magnification and illumination devices for surgical and dentistry applications. These include headlights, telescopes, and other medical device instruments. Imagine a pair of eyeglasses with prescription lenses outfitted with miniature telescopes in the center. Each design requires special design and manufacturing.

Small parts to see big

“Everything has to be small and light because we’re working on glasses that go on your face. Everything is microscopic,” says Jeff Otto, machine shop manager.

Some specifications call for zero radius and 0.3" length. Machining tiny components made from aluminum and engineered plastics requires process control, especially when putting loads on end mills that are no larger than 1/2". Dynamic Motion technology plays a big part in ensuring that the resulting parts are roughed and cut to exact specifications. Developed by Tolland, Connecticut-based CNC Software Inc. for its Mastercam CAD/CAM software, Dynamic Motion uses proprietary algorithms that sense changes in the material, allowing the tool to remain in constant contact with the material. Controlling the load allows adjustment for better surface finish.

“Depth cuts are a thing of the past with the Dynamic toolpaths,” Otto says. “We have full length of cut no matter what tool we’re using, right to the bottom.”

Because the tool is constantly engaged with the material, there are fewer tool breaks. Before Dynamic Motion, corners broke off the tools when trying to run many deep cuts.

Reducing stepovers during cutting enables tighter tolerances for tiny parts. Previously, Otto performed intricate detailing first, adding simpler manufacturing processes later. Dynamic Motion toolpaths allow him to focus on creating a more rigid part with tighter tolerances first, programing intricate geometries later. Faster material removal and fewer tool breaks have cut manufacturing by 40% to 60%. Otto says it used to take about two weeks to prototype a part; now a part is prototyped and in production in three to four days.

In-house saves time

“We have been able to cut lead times and cycle times – even whole operations – using the 3D toolpaths,” Otto says.

The software’s tool library can be customized with different settings, tools, and machine groups so that the process runs simply and quickly on the company’s 3-axis mills and lathe.

“Mastercam is completely different,” Otto notes. “Our manufacturing engineers are customizing it to make things faster and easier to use.”

Customizing jobs to the exact specifications of Designs for Vision’s engineers keeps most manufacturing operations in-house. Time and tool cost savings realized by using the Dynamic toolpaths have helped the company’s machine shop outperform some of the shops they previously contracted.

“We don’t outsource a single milled part, and we’re going to fight to get back our turned parts,” Otto states.

Fast learning

Custom work often poses unusual challenges for programmers, so Designs for Vision’s team works with Mastercam reseller Cimquest in Branchburg, New Jersey.

“My job is to help people get realigned with what they’re trying to do so they can finish their job,” says Mike Sljaka, senior Mastercam applications engineer.

When Otto needed to choose between a wireframe sketch or a solid body for one application, he and Sljaka discussed the pros and cons of the different approaches and which toolpaths would work best. Sljaka also helped him recover a corrupted file using the Merge File command to bring existing geometry into a new file between the database, and import tool operations off the file to recover it.

Busy shops, especially those working with unusually small parts in custom, proprietary jobs, don’t always have time to unearth features in their CAD/CAM software programs. Relying on resellers and forums to guide them through problems and share strategies can save time and money. When that network is vast, resources are many, so innovative parts can be machined quicker and at a lower cost.

Cimquest Inc.
www.cimquest-inc.com

CNC Software Inc. / Mastercam
www.mastercam.com

Designs for Vision Inc.
www.designsforvision.com