Posted by Brian Albert | tagged: wires, wood, automation, food, kids

A wise man once said, give a kid a peanut butter and jelly sandwich and she'll eat for a day...but give that kid a crazy, motorized, conveyor-belted contraption that makes peanut butter and jelly sandwiches and that day will be a lot more fun! (And yes, that wise man was me.)

Check out how I made the seemingly impossible possible in less than three days, a.k.a. the Wurtz family's PB&J Mechanical Munchie Machine!

STEP 1: Self-analysis

Take a long hard look in the mirror and ask yourself, do I really need a giant machine to make one of the simplest sandwiches in the world?! If you're like me then the answer is a resounding YES!!!!!!!

STEP 2: Get various 110v AC motors

Get yourself some used 110v AC motors at various speeds: 20rpm, 40rpm, 60 rpm, and 120rpm. (Sounds like a lot, but trust me you will want them in the end.) They all should have good gear ratios on them.

Very important: Make sure that you get motors that go in reverse as well!

(The reason for the AC motors and not DC is because AC is easier in the end, but hey, if you got a bunch-o-DC motors, go to town -- I'm not gonna stop the creativity on your part.)

STEP 3: Make conveyor belt

For the conveyor belt I used leather and sewed it together with my industrial machine, but you can use your grandma's sewing machine and break it....just tell her that you don't know what happened to it or how it got that way after you're finished with it. (This step is best done when she's not around!!!)

I also used four 7" paint rollers for the "wheels" and some 1/8" thick aluminum on the sides screwed to a piece of wood to hold them together. Attach one of the 20 or 40rpm motors to one of the outside edges. The whole conveyor belt system should be about 22" long.

STEP 4: Make peanut butter squisher

For the peanut butter squisher I used a 9 oz. tube of squeezable peanut butter. (There's only one major brand, so just Google "squeezable peanut butter".)

Next I built a tower out of 3/4" square tubular steel and welded it together like this:

I got my roller mechanism from the paper section of an arts and crafts store; it's called a "pasta machine." I had to modify it a bit but ultimately I made it so the rollers can spread apart from each other and be pulled back by a spring. I used a threaded rod and a nut that create the up-and-down motion. 40 rpm reversible motor for this one.

STEP 5: Make jelly squeezer

The jelly squeezer is nothing more then a wood clamp and and a custom-made cam. As the cam rotates, the clamp squeezes the jelly! Simple, right? Make sure you use your 20 rpm motor for this part. This one does not need to be reversible.

STEP 6: Assemble mechanisms, expand vocabulary

Attach both mechanisms using some wood, nails, screws and some choice swear words as you shoot yourself in the finger with a nail gun. This part is the most painful but also the most rewarding as you realize life's woes can easily be summed up with a nail gun and a perfectly placed finger.

Attach some wheels to the bottom of it and make a track that it can slide back and forth on, so that you can give your sandwich that extra bit of flair that no sandwich should be without...layering! (Besides, if you skip this step then all your jelly and peanut butter will end up in the middle, creating a poorly-made sandwich for others to mock, ultimately lowering your self esteem!)

STEP 7: Decorate, wire, pontificate

Download and print out this free switch plate that I created for the front panel. Then wire up all the motors to some switches, plug in the motors and watch in awe as people look at you with the patented "stink eye" and say, Whaaaaat?

Then explain to them that as a child, you realized that life isn't that hard but you have figured out a way to complicate even the most simple of processes and will continue to make pointless-but-meaningful contraptions as an expression of your innermost feelings, or lack thereof, for meatloaf! (The food, not the singer!)

This has been another awesome invention from your favorite long-haired Techno-Guru, Brian.