Touch Free Straw Dispenser

Hi my name is Jack Widman and I am going into 8th grade. I have made a touch free straw dispenser and am happy to share it with you. I you feel so inclined, please vote for me in the "Can't touch this" contest 2020.

1. Arduino Uno (offbrand)

2. Ultrasonic Sensor

3. Servo

4. Straws

5. Sticky pads

6. 3D Printer

7. STL files

8. Code

The body, servo mount, and wedge are 3d printed but if you don't own or have access to a 3d printer, you could try making this out of wood or cardboard.

Make sure you print the body upside down like shown here and with supports.

Print the servo mount as shown here with the flat square up and with supports.

The wedge can be printed with out supports but make sure the hollow part is up.

The electronics of this build are very simple and easy to put together.

Here is the wiring diagram that I made in Tinker Cad.

Mounting the sensor is very simple and easy thanks to the accuracy of 3D printing.

For the ultrasonic sensor just push it through the holes with the header pins facing down.

For the arduino I just used some sticky velcro strips and stuck the on the back of the arduino and then on the body but you could really use any method of adhesion you want. Just make sure that the usb and power ports are sticking through the holes in the back of the body.

It's hard to explain how to mount the servo onto the servo mount but just look at the pictures and you should be fine.

Screw to servo horns together like shown in the picture. Make sure that the screws are on the last and third to last holes. Then, after you have uploaded the code and the arduino has positioned the servo, put on the servo horn like shown in the picture.

Place a sticky pad or something of the sort on the square thing on the servo mount like shown in the pictures and peel off the backing the stick it on the body where the horn can push out a straw. I designed a little slot in the body for the servo mount to fit in but it doesn't really work so you can just use it as a marker for where to put the mount.

The reason for the wedge is that I realized after I printed the body that the V that holds the straws needed one of the sides to be a flat edge and I was running out of time/was to lazy to redesign and reprint the hole thing. Anyway to put the wedge in, put the hollow side against one of the angles and shove it down until the bottom of the wedge is all the way down the the bottom the the angle.

Congratulations!!! You now have a touch free straw dispenser. Plug it in, wait a second, wave your hand in front of the sensor, and voila a straw will pop out and you can grab it without touching any of the other straws. If you liked this project(or even if you didn't) please vote for me in the "Can't touch this" contest 2020. Thank you.