Introduction: Automatic Coin Sorter

About: In San Francisco Bay Area. Enjoying good food and making stuff out of the little things I find is what I like to do. Miniaturization of things and making things in a tight budget are my expertise. Visit my Thi…

I always have some coins laying on my table and in need to use some quarters to pay for parking. I fumble around the table looking for quarters and end up in frustration. Is there a better way to organize quarters in a package, better yet a system that sorts coins without fancy, sophisticated electronics? A simple box can do the trick and this instructable will tell you how to make an automatic coin sorter.

You will need:

1. Small package box/ tissue box
2. Tape
3. Precision knife/ blade

Disclaimer/ Attention: I have no affiliation with USPS whatsoever. Always be careful when using precision knife, it may cause injury if the knife is handled improperly. Always operate blade/ precision knife on a cutting mat/ waste paper to prevent deep cuts/ scratches on surfaces.

Step 1: Picking the Right Box

A friend of mine gave me this small package box and I thought it would be the right size for my project.
The size of the box is: ~ L8 11/16 x H5 7/16 x D1 3/4, L22cm x H13.5cm x D4.5cm

Any good small rectangular cardboard box does the trick.

Step 2: Making the Slide

Since the size of the dime is the smallest, the hole for the dime will be the at the top of the ramp (the dime will fall in first and quarter last). My box measures ~ 14cm in height, which is the length of the slide. I divide it into 4 segments, mainly for dimes, pennies, five cents and quarters. Each segment is about 3.5cm in length. Use a ruler to measure the box and divide it into 4 segments, use a pen to mark the segments on the cardboard box as shown in the photo.

Next, open up the box (as shown) and cut away the side portion of the box. The side portion should be separated in order to carve the hole in the next step.

Step 3: Cutting the Holes

Line the coins to the side of the cardboard and mark the circumference of each coins onto the board (as shown) with a pen. Keep in mind that the holes must be evenly spaced apart. Use the segment lines to guide the marking of the holes.

Use a precision knife/ blade to remove the inner part of the drawn circles. I used the pizza cutting method to cut the circles, it would be much easier to create the perfect hole.

I realized that the edges of the holes were not as smooth and it would be harder for the coins to slide down the ramp. To solve this problem, I used smooth, transparent packaging tape to tape the surface of the ramp/ slider. Cut off the tape part of the hole and use your fingers to smoothen the edges.

Step 4: Making the Segments

This is the most tricky part of this intractable. Hold and place the slider to the cardboard box (as shown) with the dime hole at the most top and the quarter at below. Close the box and the friction will hold the slider in place. Use on hand to hold the box while the other to slide your coins down the ramp. Adjust the ramp angle/ push the quarter segment down to obtain the perfect angle for the coins to slide. This is a trial and error method. Once you are done with getting the angle, reopen the box and mark the angle line on the cardboard wall (as shown).

Using the measurement of ~3.5 cm, Draw the lines of the segment (as shown).

Attention: Due to the angle of the ramp, and the nature of hypothenuse, the holes may not be in perpendicular with the segment space, use trial and error method to get the right spacing for the segment, while making sure that the coins can drop into the space accurately.

Measure the depth of the box and make 4 wall segments based on all the measurements you take (also as shown). Tape or glue the walls to the box.

Step 5: Finish

Close the box and seal it with tape, and finally you have a working coin sorter! (hopefully)

Improvements and Recommendations:
1. Use a better precision knife or laser cutting technique to make the holes better and smoother.
2. Cut out the holes on a piece of paper and glue it on top of the ramp will make the slider cleaner and much smoother.
3. Dimes and pennies tend to slide into the same segment. Perhaps combine them into the same segment anyways.

Cardboard Contest 2016

Runner Up in the
Cardboard Contest 2016