Tek Circuit Computer: Cursor Hairline

Given a machined cursor blank, clamp it into position:

Tek CC Cursor - cursor hairline fixture
Tek CC Cursor – cursor hairline fixture

You don’t want to clamp the cursor directly to the Sherline tooling plate, because the diamond drag bit would pass over two or three of those 10-32 screw holes which would, by the conservation of perversity, leave visible defects. In hindsight, I should have put a recess for an aluminum plate in there.

After a single pass at Z=-4.0 mm, add two strips of tape to protect the adjoining surface and scribble it with red lacquer crayon:

Tek CC Cursor - tape color fill
Tek CC Cursor – tape color fill

Peel the tape off:

Tek CC Cursor - tape removed
Tek CC Cursor – tape removed

Then wipe off the residue using a soft cloth wetted with denatured alcohol:

Tek CC Cursor - red cursor detail
Tek CC Cursor – red cursor detail

That looks much like the previous efforts. I’d like a more uniform trench, but I don’t know how to get there from here.

In any event, the hairline looks pretty good against laser-printed scales:

Tek CC Cursor - red cursor white laser decks - magnified
Tek CC Cursor – red cursor white laser decks – magnified

The new cursor is the lower one lying atop a laser-printed Pickett-style Circuit Computer:

Tek CC Cursor - red cursor yellow laser decks - overview
Tek CC Cursor – red cursor yellow laser decks – overview

Looks good enough to eat, as the saying goes …

3 thoughts on “Tek Circuit Computer: Cursor Hairline

  1. Just thinking out loud, I wonder if heating or cooling the material would affect the smoothness of the cut for the hairline.

    1. It’d surely affect the overall glossy surface finish! When I tried heat-forming some thin polypropylene sheet, it was never the same again.

      Now that you mention heat, though, perhaps embossing a line with a heated blade might work.

      A razor would surely make a too-smooth V notch that wouldn’t hold pigment, but a flat-edged sheet of very thin shimstock might produce a square-ish channel with maybe a ridge along each side. Either would look better than the ragged scratches I’m so proud of.

      Thanks for the suggestion!

Spam comments get trashed, so don't bother. Comment moderation may cause a delay.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s