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This is my digitally fabricated auger based pet food dispenser.  You simply load the pitcher with pet food and it is automatically pushed with the auger screw into the dish to feed your pet.  This has been tested to work with cat food and designed with a cat in mind.  Actually this is going to be a Christmas present for my sisters cat.  

In the past year I have been working to up my game when it comes to fabricating parts for my projects.  If you were to check out some of my older Instructables you would see most things I made were built with three basic tools, a drill, a saw of some sort and a dremel.  These tools serve me well but I had to limit my material choices and construction techniques to match the tools.  I was always designing parts around these limits and trying to source pre-made parts whenever possible.  I had some success with this but always thought it would be nice if I could make cuts a little straighter and make things with more complex geometry.

So during the end of 2011, I started working on a cnc router.  I finished it in Febuary 2012 and posted all the plans for it here on Instructables  DIY CNC Router  It has been an awesome tool and I have used it many times.  I've made things for my aunt, my sister, my cousin's eagle scout project and a fishing poll rack for my Dad.  Around the same time I was finishing up the router, MakerBot released the Replicator and I got caught up in all the hype of 3d printing.  I poured myself into this new subculture I found on the internet and I when I emerged from my fasination with these cnc hot glue guns I decided to buy my own 3d printer.  There are many DIY level 3d printers available but the one I decided to get was an M2 from MakerGear.   It is my opinion that this printer has the highest quality components and uses the best manufacturing techniques of any DIY level 3d printer currently available.

So now that I have a CNC router and a 3d printer I decided to work on a project specifically geared toward using these tools to take advantage of their capabilities.  The pet feeder is that project and in this instructable I will to explain how I used the machines to create some unique parts.

This design for an auger screw based kibble dispenser was inspired by Tunell and kitlaan of Thingiverse but I created all of my own 3d models for this design.  I have uploaded the design files to Thingiverse as well Pet Feeder Thingiverse #34100  
            

Step 1: Materials and Tools

The parts needed for the pet feeder are easy and cheap

  1. 2" PVC Plumbing Tee
  2. Dollar store drink pitcher
  3. PLA plastic filament for 3d printing (ABS could also be used)
  4. 3/4" Oak Hardwood board (any sheet material could be used, 1/4" Acrylic could replace this)
  5. 4-40 machine screws, nuts and washers
  6. Continuous Rotation Standard Hobby Servo (I used a Parallax servo)
  7. Exacto Knife (for cleaning up the prints)
  8. Drill
  9. 3d printer
  10. CNC router (or laser cutter)

<p>Last update, I have added a second mini servo to open and close an auger door. Cats keep picking out food all day long. Door actions is to allow it to close without getting caught up on food stacked up at the edge. </p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/HPRL-vlAiu8" width="500"></iframe></p><p>One other addition was to modify the timer so I could switch the digital display off as it was drawing too much current for the solar charger to keep up if we had a couple days of cloudy weather.</p>
<p>I finally finished this project. The controls consist of a Timer which when triggered send 12v to a voltage regulator for about 20 seconds. This feeds the Metro mini and the servo. The mini runs the servo code and stops when complete, the timer shuts off power about 5 seconds later. I am running this with a 5A 12v battery which will be tucked away out of sight. It is kept charged with a 2 Watt Solar battery maintainer. </p><p>I added a small slice of pipe to the inside of the Tee to fix a small design flaw. The opening in the servo housing that lets you slide it over the motor also let small kibbles behind the auger flange in the servo horn chamber. This can cause a jam. Once the slice of 2&quot; pipe is glued in place, the auger must be screwed in to the tee. </p><p>The electronics enclosure was made by hand, unfortunate no laser cutter at hand.. </p>
<p>Still working on the finished product but have the controls done. Will be timer based and on-demand.</p><p>Here is a real short video of the timer triggering and unit running</p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/exsSEIZ0okA" width="500"></iframe></p><p>The Arduino code and be change very simply to output more or less food, this is the amount for my 3 cats at bed time. I foresee the need for a flapper door at the end of the auger as the cats will be pawing out the food.</p><p>Will outline the electronics and code when finished.</p>
<p>Finished up the assembly but may new stands out of hardwood and change the shape possible to allow the boards and battery encloses to be mounted. I altered th lower part of the stand so it would HOLD our stainless steel cat plates in place. Next the electronics and encloses.. sure wish I had a 3D printer.. </p>
<p>I have cleaned up my auger using 180 grit sand paper taped to a slab of granite. Sanding the mating surfaces this way produced a perfect fit allowing me to use a plastic weld product (methylene chloride) to weld the pieces together. Just hold them together where you want them and lightly coat the seams and it just sucks, hold tight for about 15 seconds. I then used a hair dryer to heat the tips of the auger blades to line them up. Next filled the gap with Locktite Marine epoxy which does not really bond well to plastic but is more or less just used as filler. The TEE was bored out with a vertical drum sander similar to this <a href="http://www.woodcraft.com/product/157889/woodriver-benchtop-spindle-sander.aspx" rel="nofollow">http://www.woodcraft.com/product/157889/woodriver-...</a></p><p>Then hand sanded with 320, 800, &amp; 1000 grit wet for a perfect fit without altering the auger.</p>
<p>Please note the auger was made with the suggested PLA plastic and super glue (cyanoacrylate) is said not to work well. This is why I used the methylene chloride. </p>
<p>I have found a way to allow all 4 servo attachment screws to be used. Before attaching the auger to the server and with the horn removed, install the servo in the back cover and center the bottom servo holes and cover holes. Now put a nut halfway on one of you longer 4-40 screws. Using a lighted magnifier glass if you are old like me, apply a small amount of Locktite gel super glue to the back of the serve ears where the nut will rest and then drop in the screw shaft and nut. Hold for 20-40 seconds and unscrew the screw. You can now assemble everything and use 4 screws to attach the server, just don't crank down the bottom screws as the glue is not that strong.. Don't forget to drill out the end horn holes to accept a 4-40 screw. Use a 1/8&quot; bit and a drill press if you one, and hang on to the server. </p><p>(1/8) bit. Use a drill press if you have one and hang on to the server.</p>
<p>Ok, figured that out. There are 2 kinds of PVC schedule 40 Tees, a Sanitary Tee and a Regular Tee. The regular Tee has much less plastic inside that will need to be removed with the drum sander.</p>
<p>I am a bit freaked out.. had the parts printed and the auger is not 2&quot; but 2 5/16. Is this how bit it is supposed to be??? </p>
<p>Ordered the same servo, holes in the horn are very small maybe 1/6&quot; in dia. Holes in the auger are at lest 1/8 or 3/16&quot; What sized and type screw was used to attache the auger and the servo? </p>
<p>Been a while since anyone posted here. I stumbled upon this looking for designs that would let me feed the cats a small amount of food on a schedule. I dove in knowing I could buy an auto feeder for a lots less than I could make one like this but where is the fun in that. Hope it works cause I am committed now. Had someone print the parts, all but the bowl ($40) 10 program timer $30shipped, Arduino $30shipped, Servo $22shipped, voltage regulator (timer needs 12v rest 5v) $5, enclosure?? 12v lithium-ion battery $40, low battery warning module $5 and I am sure I will find more stuff to buy.. ;-) Original idea was 3 one timer and controller, one for each cat as they currently each get their own bowl.. Looking like $70 for each additional unit for printed parts and motor. Will post my end result. </p>
Thanks for this beautiful idea.. I took the tube of a whisky bottle for the food container. Also it wasn't easy to find the us 2 inch t-plumping piece here in Europe. My cat is a bit sceptical, let's see what happens when he gets hungry! :)
<p>I am planning to build an HTTP server from which I can trigger a feed so I will post an own instructable about all the Software parts I needed for realizing your idea. I will link it here as soon as its ready. Thanks again!</p>
<p>Thank you for this nice Instructable. I like it</p><p>Rima</p>
I am in the assembly phase and immediately ran into two problems. First, I set the CNC router to cut the holes in the wood on the inside of the line. When, I tried to put the PVC into the holes, I discovered that the PVC was slightly bigger than the hole. So, I had to use a Dremel sanding bit to make the holes a wee bit bigger. Should I have made the cut on the line instead of inside of it? <br> <br>Second, the augur is almost exactly 2&quot; in diameter. It fits into the first few inches of the PVC, but then stops when it hits the raised part that is meant to stop other PVC piping from going all the way through the T. I noticed in your pictures that your PVC also has that raised part. How did you get around this issue? Print the augur smaller? File the inside of the T to remove the raised part? File down the outside of the augur to fit? <br> <br>Thanks for the help.
Yeah, I had to do some fitting of all the pieces. I sized all the parts to fit the exact PVC Tee I had but yours is probably different. The manufactures of the T's don't make the exact same T even though it has the same use. I had to sand down the outside of the auger to get mine to fit well. You did right by cutting to the inside of the circle on the dxf, hopefully only a small amount of sanding was needed. <br> <br>When your done be sure to post some pictures!
I'm really glad you replied. I was worried I did something wrong.<br><br>Making the hole in the wood was easy. The auger is a bit more challenging.<br><br>I'll definitely post pictures when the whole thing is done. In the meantime, here is a link to the progress posts on my blog: http://beckermaker.blogspot.com/search/label/Pet%20Food%20Dispenser
Why not old mincer without knifes feeded through timer?
Did you ever find how how to control your servo. If so, are you going to expand you instructable?
Controlling the servo is easy with microcontroller such as an Arduino or Basic Stamp. I have already done this and it works well. The question is deciding how and why the food will be dispensed, a simple timer, a button, an app? I've left that up to you, I've provided the functional feeder it&rsquo;s up to you to decide how to use it. <br> <br>I'm actually thinking I may change the whole design of the feeder to be more 3d printer friendly and incorporate a very simple set of electronics for control. Don&rsquo;t know when I&rsquo;ll do it though. <br>
WOW I'M IMPRESSED <br>Keep me posed would like to buy one from you <br>Steve
Can you tell me the printed length of the auger, I have a portabee, it's a little limited on print bed dimensions.
The auger is 124mm long overall. I'll add dimensions to the descriptions so people know if they can make the parts on their printer or not. Also, if you download netfab studio basic you can easily measure and get size and volume specs on any stl file <br>
Thanks for the tip - still new to 3d printing (am still calibrating and modding) <br> <br>I'll have to find a way to knock 5mm off or print it diagonally... <br> <br>(side note, this comment system is arse, the captcha doesn't work properly when you hit the reply button...)
Greetings, The cat'll go loopey trying to dig to the fresh food - which cats of all sizes much prefer. Yup.
Your right cats are picky about the freshness which is why I haven't decided the best way to control the feeder. I don't think a timer is the best solution and coming up with something better is going to take some effort. Any suggestions?
a little outside of the box, but if you don't want to use a timer you could make an app on your phone that could schedule and/or have a feed button and alert you when the food is low. similar but alternative would be a console mounted somewhere in your house with a feed button so you can remotely feed and check levels
I'd say no worries at all about freshness, though it could just be my declasse cat's lack of refinement...after all, I buy 25lb-bags of kibble from the warehouse club (Costco) that take my cat months to eat, doled out in 1/4C increments, so &quot;fresh&quot; just doesn't enter the dinner conversation. <br> <br>I bought a commercial version of this that's got some near-fatal flaws - I think your auger feeder is the way to go. The commercial version has overly-flexible paddlewheel-configured 'fingers' on a gear with just four quadrants, and cats that are smarter than mine are apparently known to reach up in there after more kibble and be rewarded - and it's all downhill from there. I originally bought it to keep Squeakers fed while I was off traveling for a month (don't worry, neighbors were alerted to check every so often &amp; notice if she came begging - she also had an automatic waterer of my own construction)... but that was three years ago now, and both feeder and waterer are working still. <br> <br>In kitty-psychology terms, I like removing myself (to an extent) as the entity that feeds. My cat's a terrible beggar, and I found out when I got her as an adult that she will gorge herself into obesity if given the opportunity. The auto-feeder gets mad props for regulating her intake (2x1/4C per day) and getting her weight down to where it should be - and she doesn't go after me or the wife nearly as much for snacks, since we are not often associated with &quot;that weird thing that spills out food twice a day.&quot; <br> <br>
That is excellent. I haven't had a cat for years but when I did I overfed them - I see now. It would sort thru the bowl then pick up the peices It wanted off the floor. Usually I'd wait till the bowl was about used up before refilling. You got great advice there. I really get a kick out of Those that put 2 + 2 together and figure out how to &quot;Beat the System&quot;.! Thank You. G-G
A bit of &quot;Catnip&quot;.? Har.! I think what You've got going will be great for times People can't be there to feed them. Yup.
It's a beautiful invention and gorgeous, but it is very difficult
Excellent 'ible! Not so accessible but I now have access to a 3D printer so I might just try it out! <br>Might I suggest some kind f arduino to control it?<br>My youngest sister has a cat-sized dog so the size should be fine without having to worry about &quot;freshness&quot; :P
Congratulations on being a winner in the digital fabrication contest!
Thanks, maybe I'll get some more filament for the printer
Awesome! After visiting Instructables for about 2 years now I was compelled to comment on this project! It is awesome, and I hope the feeder works as you want it to. The 3D printer does impressive work, and the CNC router is pretty nice too. Thanks for sharing your project, and I wish you many more! -fab
Well I hope it may also compel you post an instructable of your own, two years is a long time to just lurk. thanks for the compliments
As a person who uses a CNC milling machine regularly, my suggestion is that you plan out the cuts, rather than just say, &quot;Here's the part, cut it out.&quot; A lot of the work in our programming department is in planning the machining order. If I were to run your current design, I would start with the slot between the parts, then go to the inside circles, then finish everything BUT the opposite edges. Then, lastly, finish the remaining edges. The code images look like an autistic person's drawing because it jumps around from feature to feature, but it makes for parts that are much less likely to jam up the way you describe and still saves on material. I would also recommend tabbing the material that is to be cut out. It is a lot easier to hand sand a 0.5 x 0.025 tab than to sand out the marks where the tool gouged the part.
Your order of cuts would work much better and I'll keep that in mind for the future. It should be easy to do with CAMBAM. I did leave tabs, so I don't know exactly why the part broke.&nbsp; The final&nbsp;pass depth may have been off.&nbsp; As far&nbsp;as the&nbsp;tooling marks left from the jam, I'm leaving on the wood, no sanding.&nbsp; It just be a reminder to set things up well and my sister's cat won't care.&nbsp;
I recently discovered an auger in a toner disposal container from a copy machine at work - an empty, surplus one, mind. That, combined with a defunct blender, might do the trick... It's going on my list...
Seems a bit over-engineered, but I like it. :)
My first thought was, where does one get a great auger assembly like that? Ah, make it yourself! Nice work!

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Bio: I enjoy building things more than actually using them.
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