board and Boolean

[eartaker]

Was traveling today on my home and had a layover in Minneapolis for 3 hours... though I would pull out the laptop and play with some solids in Mastercam X3. Here is the machinist puzzle created with boolean functions.

[ObrienDave]

You got me thinking...
I actually have one of these from the Westec show in Los Angeles.
Don't remember what year it was but, if I remember correctly it was about 1985 or 88.
It's made from brass and was done on a MicroServo brand machine about the size of 2 shoe boxes with a 1/8 ball mill.
I waited in line for about an hour just to get one.

Eartaker,
In your model, in order for the inside cube to be free, read 'loose', you would need to cut deep enough to to clear the corners of the inside cube.
That means the little cube would have to be smaller across the corners than the round cut.
What prevents the small cube from falling through the round cuts?
The logic of this 'puzzle' escapes me for now.

P.S. Model done in V9 with no *!!!SHUDDER!!!* boolean

[fizzissist]

I actually had to make a cube just like that (admittedly without the floating center feature) a couple of years ago...6"sq, ~5" holes, tapped and helicoiled 12 plcs each face, blind 8-32, and clocked so the hole bottoms didn't intersect because it's in a high vacuum.....in pure, oxygen-free copper. Genuine PITA.

Think that's bad? I have another one to make here in the near future. (I'd like to call in sick that day...but it'd be waiting for me when I got back...)

For the trick part with the center piece, fixturing is the key for the very last cut. One method would be to have screws in the middle of the jaws holding the outer part that could be adjusted in to hold secure the center.

[eartaker]

truthfully I have no idea what would keep it from falling through and Im still working on how to make the piece so that the cube doesn't fall out. you are correct that the corners would have to be smaller then a Dia. of the circles. I kind of like yours better how the whole piece wild be left inside of the cube.

[Toonz]

A dovetail cutter or something very similar would do the trick. It's wider at the bottom of the tool than at the collet end. Thus your opening at the faces of the outer cube would be smaller than the cube inside.

[ObrienDave]

OK Toonz,
Here's one done with a standard 60 degree dovetail cutter.
I did the model in SolidWorks (because it is easier to tweak) and imported the parasolid to Mcam.

[Toonz]

Sweet! Looks like the desired end result to me, but it doesn't matter what I think as long as you are happy with it.

[eartaker]

That is awesome, don't know why I didn't think of using one.

[ObrienDave]

eartaker,
I didn't think of it either, until Toonz mentioned it!

One day I told my wife, "I'm getting old and senile".
She replied, "Getting???"