Archive for August 13th, 2015
My Sony HDR-AS30V is an action camera, but requires an external case / frame to mount it on anything. Here’s the camera inside its AKA-SF1 Skeleton Frame atop my helmet:
Four 1 mm tall ramps on the inside of the black base (the part just above the yellow sled) snap into 2.6 mm square sockets in the skeleton frame surrounding the camera. For an unknown reason(s) that surely involves applying forces I don’t remember, an opposing pair of those ramps broke off, leaving the other pair to loosely hold one end of the camera in place.
In this picture, the left ramps (one visible) are missing, leaving a square-ish gray scar that’s nearly indistinguishable from the reflection on the intact ramp on the right:
Surprisingly, the round head of a brass 0-80 machine screw fits neatly inside the square socket on the frame; they’re a bit more than 1 mm deep. The approach ramps visible below the sockets guide the latches on the base:
So I figured I could just shave off the remaining two latch ramps, drill four holes at the proper spots, and replace the plastic ramps with metal screws.
I clamped the skeleton frame to the Sherline’s tooling plate, aligned it parallel to the X axis, put the laser spot dead center in the square socket, then snapped the base onto the frame. The laser spot shows where the drill will hit:
A carbide drill did the honors:
That’s a #55 = 0.0520 hole for 50% thread, rather than the proper 3/64 = 0.0469 hole for 75% thread, because that’s the closest short carbide drill I had; an ordinary steel twist drill, even in the screw-machine length I use on the Sherline, would probably scamper away. The hole isn’t quite on the sloped bottom edge of the base, but it’s pretty close.
The first hole didn’t emerge quite in the center of its ramp scar:
Which made sense after I thought about it: the ramp tapers to nothing in the direction of the offset, so the hole actually was in the middle of the matching socket.
Threading the holes required nothing more than finger-spinning an 0-80 tap:
The feeble thread engagement didn’t matter, because those mysterious tabs-with-slots (possibly for tie-down strings?) just above the holes were a perfect fit for 0-80 brass nuts:
The screw heads extend into the sockets, hold the frame solidly in the base, and make it impossible to pull out. Although the frame still slides / snaps into the base, that seems like it will wear out the sockets in fairly short order, so I’ll unlatch the frame (with the yellow slide latch on top), open it up, ease it into position, and then latch it in place. That was the only way to remove it from the original latches, so it’s not a big deal.
I should add a drop of epoxy to each of those nuts and perhaps fill the screw slots with epoxy to keep them from abrading the plastic inside the sockets. Maybe a dab of epoxy on the heads, followed by latching the frame in place, would form four square pegs to exactly fill the sockets.
This was a straightforward repair that should not have been necessary…