Fido Feeder

In this instructables tutorial, we will show you how we made an Automatic Dog Food Dispenser which will dispense an amount of dry food at a chosen time of the day. Perfect for when you must leave Fido by themselves, and would rather that they don't starve.
Powered by an Arduino, this project involves a little electronics, a 3D printed screw, and a bit of construction with MDF/Acrylic.

Step 1: Required Materials

Electronics:

1 x Arduino (We're using an Arduino UNO)

1 x Continuous Servo (Can be bought or an ordinary Servo can be modified - Search Google)

1 x 16x2 LCD Screen

1 x Potentiometer

1 x Power Supply (Anything above 500mA should have enough juice for the Servo and LCD)

1 x RTC

Numerous jumper cables

Materials:

1 x 3D Printed Auger (Screw Mechanism)

1 x Perspex Tubing (40mm Diameter x A little over a Metre long)

1 x 600x400mm sheet of clear Acrylic (3mm)

2 x 600x400mm sheets of green Acrylic (3mm thick)

2 x 600x400mm sheets of MDF (6mm thick)

1 x Hinge (We used one 110mm Long)

Step 2: 3D Print the Auger

One of the first things to do should be to get the main mechanism done and dusted, it's by far the easiest part, so long as you have a 3D Printer handy.
Here we have kindly attached the .stl file that we created, though you're welcome to create your own of course! It needs to be just under 40mm wide to fit inside our later tube.

NOTE: This CAD file does not include a 6mm diameter hole for the Servo motor at the base! This can either be added in if you are CAD savvy, or drilled in afterwards. This is not included as not all motors will have the same width at their rotational section!

Step 3: Electronics Time!

So now we have the Auger, the next most important part of this project is the electronics. Here we have, once again, provided the Fritzing Schematic for you to follow. It utilises all the components listed in Step 1, so make sure you have them handy!

Step 4: Let's Code!

Okay, so you have the main pieces. But they are useless without the Arduino telling them what to do, we have included the code here that we used for our project. Note that there are two seperate files, Time_Setup and Newest_Code, the former is to setup the RTC with the correct date and time, the latter is the code that will gather this feedback and use it to activate the motor at a set time.

The line to set the "Motor Alarm" is in the Void Loop, for example to feed Fido at 6:00pm everyday change the line to "if (hour == 18 && minute <=0) {"
This will run the motor for one minute at precisely 6:00pm, which is plenty of time to dispense a dog bowl full to the brim. The motor will turn itself off after this minute.

Step 5: Pipe Dreams

The next stage will be to construct our pipe that the auger will work inside, this is a relatively simple process but you will need access to a bench drill and either a bandsaw that can cut at angles or something else similar. First off we will start with a metre of 45mm wide acrulic tubing (inside width 40mm), cut this into two parts, 750mm and 250mm. Next you will need to fashion a 90 degree angle between these, to do this you will need to cut a 45 degree angle in each pipe. When attaching these together you should smooth these on a buffing machine, it will just make it a lot easier to glue together. We reccommend a super glue over an Acrylic cement here!

Once you have a shape as seen in the 4th picture, it's time to create the hole that the food will fall into. This will be 150.5mm from the underside of the 90 degree angle. The largest hole we could feasibly use here was roughly 30mm diameter, this is because the drill bit we are using is tapered and that's as far as it will go. A flat drill bit is inadvisable here as it might crack the tubing.

Step 6: Box It Up!

You're probably going to want to house all of your hard work in a nice little cradle, right? Of course you are, this process is pretty straightforward. All that is required to follow our step exactly is a Lasercutter, we will be placing the 6mm MDF in here as well as our Acrylic!

We have attached the illustrator files for you to use, for creating the box. If you choose to make your own remember to leave holes for the pipe, LCD and power cable!

Once you've got all the pieces it's time to glue them together, wood PVA will be the best option here, make sure to use supports to ensure you get perfect 90 degree angles!

Step 7: The Inner Sanctum!

You may notice at this point that there are very limited supports for your tubing when it is inside the box, we shall now change this!

Basically you will need to add a small block either side of the tube as it enters the box, to prevent it from moving around. The main part of this is the block above the tube, this simply bridges the gap between the tube and the soon-to-be-created hopper! Although we haven't shown it in detail, it is simply drilled with the same tapered drill bit as the pipe, so that it has a nice slope to encourage the food to fall down.

Wood glue or super glue is sufficient to hold these blocks in place. You may also notice that there is a lot of masking tape in place here, this is because all of this will be invisible once the hopper is in place, however you may be tidier and more elegant if you wish!

Step 8: Hip Hopper

The hopper is pretty important as this will hold all of the dog food, for this project we went for a minimalistic yet elegant solution. The Illustrator file included contains the four sides to the hopper, once you have them cut on acrylic you can add the MDF struts. Each strut should have 45 degrees angled on each side. These are not essential, they do not add any strength, they are simply in place so that they lie flush with the four corners and the base connector.

To create the inverse pyramid shape you may wish to glue these together, however we felt that the flexibility of just taping them together on the underside actually aided in placing the hopper inside the box. Totally your call!

The hopper should lie flat on the base connector and the only thing showing should be a small hole and the Auger.

Step 9: Finishing Touches

At this point, everything is pretty much done! Fill the hopper with dried dog food and when the clock hits dinner time, Fido gets food. But it's maybe a bit risky to leave the food open, for sanitary and odour temptation purposes! It's best to implement a lid on the top, the one we've made is a simple clear acrylic piece with a Paw Print design on it.

Again, we have included the illustrator file so you can cut this out yourself, once you have you will need to attach the acrylic and back of the device with a hinge. We would advise super gluing this as the MDF is likely to split if you drill a hole that close to the edge.

Once you have completed your lid, give yourself a pat on the back! You're done!

We hope you enjoyed this tutorial and happy creating!