I finally 3D-printed it and put the motors and sensors, aka buttons and the scroll for mice, where they should be. I made two sides so I verify the design. Test the grabbing and movement, I did not print the female handle because I wanted to test the other stuff first.
The white gear at the bottom in the gif below has a 3D-printed gear glued to it, like the yellow gears in the previous project log. And this is just a show gif showing that I had to take the chassi apart and then glue it back together (the last part with the motor). Otherwise I wouldn't be able to get all those things in there.
And as you can see the gears line up and the total reduction for the motor is 4^4 = 256, which then goes straight to the male handle from another cube. Fyi when that motor was running it sounded like a drilling machine. Imagine having 20 cubes moving simultaneously in front of you, lovely noise. On a serious note, it's not acceptable.
This is how one side of the cube looks from the inside 360 degrees. One motor is missing, but you'll see it later in the third gif.
Luckily everything fit snuggly on the first go, that usually never happens. And if you want to see more of this model then go download the file cube A. In the *.blend file I've divided the parts in 7 layers, if you're not familiar with blender then here's a crash course. Right click marks objects, G-button grabs the object you've marked, Left click accepts the movement the G-button did, or other similar actions. H-button hides selected object. If you want to see a particular layer you press that number on your keyboard, if you want to see more layers at the same time then hold down shift while pressing the different numbers. If you R-click an object, hit G and then Y, then you'll move the object in only the Y dimension.
Oh well, enough about Blender, in the next gif there's two sides screwed together, forming 1/3 of a cube. The reason for this is to verify that even the chassi fits snuggly, which it does. The red side has the male handle attached to it, and the motor worked splendid with the handle, moving it correctly 8mm out or all the way in. When it moved 8mm out there handle also stopped because it hit a button, aka a stop sensor.
So all is fine and dandy, then I take them apart and put them together as if they were two different cubes, which can be seen in the next gif. At this moment I see that the male handle is not moving out exactly 8mm, which it kind of must. Otherwise there won't be a splendid connecting with the female handle, and if that doesn't work then it's a major failure. But yeah, around this time I understand thanks to the 3D-printing that these handles have way too low tolerances, also that it's kind of hard to put the connectors inside the handles. I did not put any real connectors in the male handle which are shown in these gif's, and if I would've it would've taken too much time. So no, I don't like these handles at all.
So around this time I realize that I need to use better handles. Ones with good fitting and ones that I haven't 3D-printed, because it's time to do a reality check. Like, what kind of connectors are out there for circuits? Well... regular 2.54mm male headers 3x2 and 3x2 female headers are.... pretty awesome. And I used that for an old design I made in October last year... and that design looks like this youtube video below.
It's not perfect, but it's also not stupid. The... what should I call it... the grabber, is only moving 10mm in each direction, and the female headers are spaced 20mm apart. You might think "Harry... that's not smart, that means that the cube can't move from one female connector to another female connector". But here's where I say that it will always be two cubes next to each other, and while one is moving the grabber 10mm one way, the neighboring cube is moving it's grabber 10mm the other way => 20mm. And that way the cubes will literally "walk", like your legs, across the cubes. Also, I like these connector designs.
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