Page 48 - CNC West Oct-Nov 2021

“StarGate” - Fixturing for the Future
Article and photos provided by Mitee-Bite
OP2 solution using 16mm Threaded XYZ Xpan- sion® Pins.
Akron Gear & Engineering had a problem to solve – how to vertically hold a large 1-ton ring (4340) as their VTL was down, and the customer needed it ASAP. Working with the Engineers at Mitee-Bite Products they came up with the solution. Less than 10 days after the initial call Akron Gear was making chips and more efficiently than in the past.
Dennis Miller, of Akron Gear & Engineering said, “To the best of my knowledge this is the largest one our customer has required in the States. Right now this is a one-time piece and we are doing it this way as our large VTL is currently being updated and rebuilt, and to keep the work in-house. I had the pleasure of working with Rich Jones from Atwood Industries and Mike Witzgall from Mitee Bite Products - getting the right informa- tion and clamps to hold this.”
David Bishop, general manager at Mitee-Bite Prod- ucts said, “There was a lot to be considered with this project, going vertically opposed to their VTL, now all the stress from the weight of the part is working against you and the machining forces are applying even more
Each Pitbull® Clamp develops 12,000 lbs of pres- sure.
pressure on the pins and clamps.” After discussions with Michael Witzgall, senior applications engineer at Mitee-Bite, a modular solution mounted on t-slot sub plates was recommended. Using the new Mitee- Bite Heavy DutyTM T-Slot Clamps with Blunt Edge Pitbull® Clamps and the large Multi Fixture Stops for OP#1, then Modular XYZ XpansionTM Pins for the I.D./O.D. and facing operations leaving the part com- pletely free from any clamp interference.
Dennis went on to explain how the project took shape. “The top section had no real support and the only issue encountered was the span between the top supports due to the position of our angle plates... it created lots of vibration. Initially, I was using a 6” face mill to cover the entire face in one pass. The crust was much harder than under the surface, machining this un- supported portion of the ring resulted in chatter marks. I switched over to a 4” face mill to get thru the surface, once below the crust I was able to go back to the 6” mill which I ran at a .060 depth of cut and 90IPM feed rate. It still had a very slight vibration during machin- ing. To take a final pass for the finish I used a 6’ boring bar with a single point insert which produced a nice fin- ish and cleaned up all of the vibration. Thanks to Mike for suggesting the XYZ XpansionTM Pins, which I be-
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CNC WEST October/November 2021