Many years have passed since I originally made a batch of SFT-style eye covers for my beam-break body milling. I made a long boring video detailing the process back in 2009, and wrote a tech article about it which can be found here. Skipping ahead several years, I finally ran out of left-side eye covers in 2014, so I had the need to make more to keep them available for eye mods. I took the time to update my machining process which is the topic for this page!
Manufacturing Process:
Machining the eye covers is done using a three-part process. Compared to the old video I made in 2009, some small changes were made to allow better results:
· The machining program produces both a left and right eye cover. The right version can be used as a replacement for any Shocker, while the left version is used with beam-break Shocker SFTs.
· Eye cover outside surface is flat, instead of "slightly angled" as with the OEM eye covers. This saves a tremendous amount of time, and is barely noticeable. The eye cover still does its job but stick up next to the ball detent by like 1/64".
· The updated manufacturing process relies on a custom fixture, which is used to trap the eye covers during the milling process. The overall proceedure is easier in terms of mass production, but required some upfront work to create the fixture and custom screw caps used to hold the eye covers.
Milling process 1 of 3 - The eye covers' inside-surface is milled into raw material. The material is held in a typical milling vise with enough clearance around the outside to prevent the milling tools from coming in contact with the vise jaws. Once finished, the eye covers are still held together by their "skeleton" material around them.
Milling process 2 of 3 - The special SFT eye cover milling fixture is installed in the vise. The skeleton of eye covers is flipped around such that the outside-surface is facing up. The purpose of this machining process is to cut the area where the threaded ball detents sit. This inside area is used to hold the eye covers down in the final process
Milling process 3 of 3 - The eye covers are individually screwed down to their fixture using small screws with special washers. This final milling proceedure cuts the finished "outside" surface of the eye covers, which removes the unused skeleton material holding the covers together.
Finishing:
The eye covers come out of the machine nearly finished, but they have some sharp edges and burrs leftover from the cutting tools. I don't polish each individual eye cover, but I do run them all over a hard buffing wheel which is meant to smooth off the sharp edges. Afterward I quickly hit the eye covers with a layer of scotchbrite pad which obscures the endmill marking on the external shape.
After anodizing, the eye covers look like this:
I sell these eye covers on ebay!