anelok: main case, top: conclusions [4/4]

Werner Almesberger werner at
Sun Dec 1 22:49:49 EST 2013

For a first try, the result looks encouraging.

Besides the isses I've already mentioned, there are also some design
flaws caused by the size of the endmill:

- the LED column should look like the one in the Y-Box, instead of
  being a U-shaped protrusion from the sidewall. The reason for this
  shape is that the bit doesn't fit between column and wall. I can
  solve this by moving the LED further away from the wall in a
  future layout revision.

- the lanyard hole and column are missing. I included them in the
  CAD design but had to "if" them out because the bit is too wide
  for separating the column from the wall, let alone making the hole
  for the lanyard.

The reason why I'm using such a large bit is that I need to go fairly
deep (sheer walls of about 7 mm) and endmills typically have a
diameter to depth ratio between 1:1.5 and 1:3.

So I either have to find small bits with a larger ratio (and try not
to break too may of them), add a tool change (use the large bit for
the coarse work and a smaller one for the problem spots), or see if
I can move things to more accessible locations.

I could also use a drill, making a series of overlapping holes to
remove most of the material, then move the drill sideways very gently
(like a mill) to remove the bumps that remain.

We'll see. Some research is clearly needed.

Last but not least, a quick look at how the bottom side components

The knob of the switch is precisely flush with the outside, the USB
receptacle is reasonably close to the outside, and the memory card,
while protruding "into" the inner wall, doesn't touch the outer wall.

So all this worked as planned.

- Werner

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