Instructables
Picture of Build a mechanical Lego Binary Calculator
I decided to take the time to design this as a Christmas gift for my stepmother, who is a math teacher.  That would be why it is Christmas colored.  After a day or three of hours put into designing it (and the case), I find out that Lego doesn't let you order your designs from their digital designer program anymore.  So I count each piece by type and color (too much time invested to give up), and then go to order the parts through Lego's "Pick A Brick" program.  The price was well over $1,000 which was not affordable for a jobless recent HS graduate.  I checked 3d printing services about their prices to have the parts 3d printed, and I think it was an even higher cost due to their greediness.  I'm sure it can be printed for under $100 easily, but I do not have a 3D printer sadly :/
Hopefully someone who has a 3D printer or a LOT of specific Legos, will find this instructable useful and save my time/efforts from being in vein :)  A thing to take into thought before spending money on this:  This hasn't been tested and I imagine all of the tolerance limitations legos have may cause it to not work.  This is a concept design. 

I didn't really want any springs, and hate when rubber bands are used in machines for long term use, so I designed it to work off gravity and it has to be standing up in order to work.

I didn't think of the entire thing, I just got the idea after learning how computers add numbers, and based the logic gate designs off of this guy's gates.


Please point out typos and mistakes i've made.  Kinda made this quickly.
 
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hifatpeople (author) 6 months ago

https://docs.google.com/file/d/0By8KfnD4pKaUeWFGY3...

There's the completed calc file for lego designer. If someone were to build it, don't go off of my design for connecting the inputs and outputs. they connect parts that are too far apart and the plastic will flex before the other input gets switched.

hifatpeople (author) 7 months ago
I looked on ebay for each individual part actually. Found many good deals but was still over 200 which is more than i could afford
hifatpeople (author) 7 months ago
The lego parts are cheaper via 3D printing, but the printing services I tried had a huge service fee, at which point I quit because christmas was a few days away.

Injection molding isn't really practical for my needs because I only want one. And if it were to be 3D printed or injection molded, I'd probably redesign it in Autocad to get rid of the design limitations and bulk that comes with lego designs.

Though I may just do that. I don't really know why people would fund a calculator thats not for them, and I'd probably get sued by LEGO if I tried to sell this. But it might be something to consider if i redesign it.

I'll go scavenge through the lego bin and see if I have enough parts for a gate.
msraynsford7 months ago

It looks great and I would love to see a full version of it working at some point.

I'm pretty sure that Lego parts will be cheaper than 3D printed parts. The injection moulding process is more expensive to set up but cheaper and faster once it's running. 3D printing all those parts will be slow which is why there is such a markup.

Would it be possible to make on of each gate you're proposing, the videos would really help people see what's going on here. Once you had that done I reckon you could head to kickstarter and people would soon give you the money you need for a full version.

wilykat7 months ago

Looks like you made that with LEGO Digital Designer? If so, you should look for LDDManager which can make a complete part list from LDD file that you can then copy to Bricklink site. Bricklink is like the ultimate Pick A Brick, with millions parts from many various sellers. You can probably get everything you need to build one for about half of what LEGO wants.