Awards & Engraving

March '20

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A&E MARCH 2020 • a-e-mag.com 49 other issues. For best results, he advises using a chip removal system, the spindle must have over-travel capability, the soft- ware must apply over-travel, and the cutter must properly set. WHAT NOT TO DO For all its versatility and advantages, there are a few no-nos that must be con- sidered with rotary engraving. Coupled with best practices, avoiding these things creates the ideal rotary engraving process. "The biggest no-no is trying to deep engrave on really hard metals," Spector offers. "Trying to use a carbide or steel cutter on the harder metals will eventu- ally work, but your machine won't hold up nearly as long as it should because of the stress you are placing on your motors, bear- ings, rails, etc." The extra cost of repairs is never good for the bottom line. "Because rotary engravers apply lateral forces on the materials when the cutter moves on axis, it is important to firmly clamp objects in the vice or on the T-Slot table to avoid movement of the object," adds Harris. The good news is there are a variety of jigs available to hold different substrate shapes. Despite those few challenges, rotary engraving is overall a great personalization method that has a lot to offer. "The rotary engraver (machine's) greatest strength is the ability to provide the traditional engraving appearance in metallic materials and gift items that people find elegant," finishes Harris. Processing Tips for Working with Metal Anthony Harris, Gravotech • When engraving and cutting hard metals, consult your sales representa- tive for advice. • When surface engraving metals, con- sider using a rotating diamond cutter — it provides a wider scratch in com- parison to drag diamonds. You can also rotate the diamond to yield a deeper and wider cut line. • If enough depth is desired to paint-fill the engraving (.005 +), use a carbide cutter. • For best engraving results, select the cutter designed for your material (soft metals or hard metals). Stainless steel calls for more specialized 1/4-round cut- ters and lubrication. • Feed rates and cutter rotation speeds should be adjusted for the cleanest cuts. • Engraving harder metals requires you to increase the spindle downforce spring in order to force the cutter into the mate- rial. If spring tension is too light, the cutter may not achieve, or maintain a consistent cutting depth. • When cutting stainless steel, tool steel, or hardened metals, you benefit by using an optional collet spindle or high-frequency spindle and lubrication system. • There will be some trial and error while you dial in the best settings for your machine on any given material. Once you arrive at the best material setup, it is saved with the engraving job and can easily be recalled and used on similar materials in the future. • Start with very low X, Y, and Z feed rates and increase them until you find the fastest settings while maintaining good cut line quality and preserving the cutter. If your Z plunge rate is too fast, you risk fracturing the cutter tip on impact with the material. A&E

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