End Milling Procedure

Overview

After rough-cutting the fibers for approximate length, we end mill each bundle for a more precise cut and it eliminates the ragged ends caused by the Dremel. Each light guide is cut to ~166.6 cm. We also end mill the SciFis to ~2.00 cm.

Pre-End Mill Procedures

LG Pre-End Mill Procedure

This procedure requires two technicians.

• Don a pair of gloves.
• Bundle a set of 30 light guides into a fiber collar using the bundling tool. Tighten the collar so that the fibers cannot change orientation but may slide through the collar.
• Use the flat face of a piece of aluminum to align the ends of the fibers flush so they all project the same distance beyond the collar, approximately 1/8 inch. One worker may hold the metal, while the other pushes the fibers against it. Tighten the collar around the bundle so it will not slip.
• Keeping the fibers in the same orientation, fasten a second fiber collar around the bundle. If constant pressure is kept on the top, bottom, and sides of the bundle with your hands, the bundle stays in a square matrix and is able to be placed in the next collar very easily. Tighten the second collar so that the orientation does not change but the fibers may slide through.
• Slide the second collar so that the distance from the outer edges of each collar is 166.6 cm.
  • This step is easiest when one technician holds the tightened first collar and the measuring tape and the second technician keeps the fibers straight and slides the collar to position.
• Tighten the second collar so the fibers cannot slide.
• Place the fibers inside the end mill sock to protect the fibers in their transport to the machine shop.

End mill sock.

SciFi Pre-End Mill Procedure

• Don a pair of gloves.
• Bundle a set of 36 scintillating fibers into the 2 cm thick collar. There is no 6x6 bundling tool so you have to do this by hand. Loosen the 6x6 collar, place it on a clean, flat surface and place each scintillating fiber in until it is full.
• Ensure that a bit of each fiber is extending past the collar on each side by lifting the loosened collar off the table by about 1/8 inch.
• Tighten the collar so no fibers slip out.

End Mill Procedure

The following steps are for a trained machine shop technician. Follow all safety measures as set by the machine shop.

Safety Information: Eye protection should be used to deflect fiber debris, sleeves should be rolled up, hair pulled back, and jewelry secured.

A view of the collars being fastened into the end mill. The fibers must be tightened and very secure to avoid damage.

• Clamp one fiber collar into the end mill, careful not to put any stress on the fibers.
• Place a double-fluted 3/8-inch end mill into the machine.
• Set the end mill to 1400 RPM.

Setting the end mill to 1400 RPM.

• Bring down the end mill so it just touches the collar.
• Set this z position as 0.

Setting the z-position to 0.000

• Bring the end mill to the top of the fibers and note the z position.

Z-position of the tallest fiber.

• Move the end mill away from the fibers, and move it down the z direction by about 0.010 inches.
• Start the end mill and move the flute around the fibers to mill away a portion of the fiber.
  • Wipe the surface/use the air blower on the fiber between each mill to remove fiber debris and keep it from getting wedged under the cladding.
  • Be sure to mill slowly around the fibers so to not bend or break the fibers. A slower sweep will result in a better cut.
• Repeat the previous two steps until the end mill reports the z position to be about 0.010-0.000 inches.

Ending z-position.

View of the fiber debris caused by the end milling process.

Finished end milling.

• Repeat the process for the other side's fiber collar.