chicken feeder using stepper motor

 Evaluate these programs   19/4/2024

https://www.instructables.com/Automatic-Chicken-Feeder-3/

needs T-cobbler, the DRV8825 and the HX711 

Software needs MySQL

On R-Pi it uses one pin for the steps and one for the direction. I don't understand that because it uses an Archimedes screw to feed the food. 

https://www.backyardchickens.com/articles/a-raspberry-pi-controlled-diy-coop-door-with-python-code.74113/

Simple DC motor with pulley to raise/close heavy plywood door. 

https://www.instructables.com/Automated-Chicken-Coop/

Uses R-Pi B+  MySQL, Ordinary brushed motor. 

https://www.theneverendingprojectslist.com/raspberrypiprojects/automaticpetfeeder/

rotating 6 blade paddle for supplying food. 

https://www.instructables.com/Automaticcoop/

RFID tag to detect chickens, also ultrasonic sensor 

School project.

uln2003 for driving stepper motor

Stepper motor has a pulley for lifting door. 

This one gives good simple explanation of connections that I can use and basic Python program for R-Pi

https://www.electronicwings.com/raspberry-pi/stepper-motor-interfacing-with-raspberry-pi

Getting HW-95 motor driver wired up:

https://popularelectronic.com/Details/HW-95--L298N-STEPPER-MOTOR-DRIVER-MODULE

Testing 3D cad programs -

 There are a number of 3D design programs available, but which is the best for me? 

I have been using TinkerCad, partly because this is the one suggested by Robert Murray-Smith in his interesting YouTube videos, but my son suggested FreeCad, and Tom Stanton suggests Fusion360 and Onshape.

To evaluate these programs I will attempt to create a chicken feeder consisting of a rectangular tube with a sliding rectangular tube inside it. Both tubes have holes in them to let food into the inner tube and dump it out when the tube has moved. 

For testing I will start with a new install of Kubuntu 22.04 on my quite old computer, and where a browser is required use Firefox. 

Evaluation criteria will be along the lines of: Ease of installation; how to get started; Ease of visualisation and adding/subtracting parts from the design, and exporting the design to a 3D printer. 

TinkerCad:  This is a browser based program, with all the elements on-line. https://www.tinkercad.com/dashboard  No storage is required on the computer.  It is necessary to create a logon, which is simple. To get started on the initial screen there is a ‘+ Create’ button that brings up a clean homeplate with a title label at the top that is a random name that is easily changed. 

To start, drag a block from the side panel of shapes on to the homeplate. There is a panel of basic shapes shown and you can select others from the shapes library. At this point I am inclined to select a shaded out shape that is the remove material shape, make it slightly smaller and put it inside the box to create a tube. Then I can group these two shapes and elongate the box to create a tube. It sounds simple but takes some practice to get positioning of components right. 

Once the shape is complete and all grouped together via the ‘group’ icon, I can export/download it as an .stl, .obj  or .gbl file for preparing for the printer.   Cura then gives me a slightly more realistic view of the object to be printed.

FreeCAD:  Version 0.21.2 downloads as an appimage. This means that it can be run directly once the properties of the appimage have been changed to specify ‘executable’.  It starts up without any need to login again, as you might expect. Despite the fact that there is a cube in the top right to specify the view of your object, it is necessary to Hit the ‘+’ to start a new design, then to change the name in the properties box in the bottom left. Then I have a blank build area.  In the top  selection box there is a label ‘Start’ and this gives you a selection of shapes to start with. I selected ‘part’ and then chose box. On the options bar this then shows a variety of shapes. Some of the technical terms in this program are beyond the simple modeller. I don’t know how I am going to change this box to an empty shell. It is not obvious how to do dimensioning and the help is no help. Users Documentation from the Help menu suggests adding add-ons for dimensioning. It goes to external 3rd party add-ons. 

The design is saved with a .FCStd extension, but can be exported in about 40 formats. 

Fusion 360:   This is a downloaded program for personal use. It seems to want my details more than once. I had to re-enter them to activate the download. [ Spelling mistake on web-page - my bugbear] Then it seemed to have a run-around before I discovered that there is not a linux version.   

Evaluation stops here. 

Onshape:   This is available as a free to non-commercial single user (Me!) and pay for more  features. There are quite a few questions in setting it up, but an important one is setting the dimensions from the default imperial to metric if you need that. 

It is an online tool accessed via the browser. I like that it has a Quickstart Introduction link on the front page. However, I found a youtube video on getting started that was better to get started with my simple design.  https://www.youtube.com/watch?v=pMWnsHpDlQE&list=PLxmrkna-ixrIQmsPR3MITi4Ru1bnMH4-l

Now that I have my creation, I need to find out how to export it for my 3D printer.

Summary   

And then I found:

https://www.youtube.com/watch?v=J--QVhGheP4

So I gave up.

The Author:  Peter Merchant is a retired Electronics Engineer and University Lecturer. My engineering career has always been involved with Data Communications. I have programmed in a number of languages in the course of my work, and since retirement. Nowadays I guess I would call myself an Inventor/maker/fixer. I learnt Mechanical Drawing/Draughting in 1972 as part of my Engineering degree. 

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4 April 2024

I have just seen a video  about a new product called Plasticity.  https://www.youtube.com/watch?v=Lt29GkADMZ8&t=318s    It seems to have been created by a single guy, and from reading about it he is behind the iron curtain and can't get upgrades on some stuff to improve it. 

Feb 2024- Solar panels have paid for themselves - sort of.

 I have just done my reckoning for the year and  the solar panels after 9 years have paid back the cost  of purchase.  They cost £6000 and at the end of this year have paid back £6150.

Lots of caveats in here though. I figure that if the £6000 had earned 2% it would now be worth over £7000 but of course interest rates have been down and are now up again. I have not adjusted it annually.

I costed in the benefit due to reduced electricity/gas bills compared to the cost of these in 2014. Except for the last two years my bills have been £2-300 lower than 2014. Caveat: consumption may be different. 

Caveat: the last two years the cost of electricity and gas has been much higher and therefore my costs have been greater than 2014, so I have not offset them in my calculations.  It wouldn't have been easy as the rates have fluctuated in the last couple of years.