Hungry Cattle Attachment
One of the challenges that up until this point we weren’t able to complete is Hungry Cattle. Its time to put that right!
I started with the default attachment shape created previously and built onto that,
The simplest solution was to have a hopper (originally sized to fit a single trough’s worth of feed) with a servo driven lever on the bottom to allow it to be emptied.
![](http://www.thelemmingfarm.uk/wp-content/uploads/2022/06/image.png)
![](http://www.thelemmingfarm.uk/wp-content/uploads/2022/06/top_hungry_cattle.gif)
The MG90 servos used in the robot arm seemed reasonable powerful so one was designed into this model.
The challenge was to design the lever in such a way that the horn attached to the servo was embedded into the lever so there was no gap with the hopper hole
![](http://www.thelemmingfarm.uk/wp-content/uploads/2022/06/side_hungry_cattle.gif)
The design was 3d printed and worked exactly as intended.
Here it can be seen being tested with a simple servo tester.
We used a breakfast drink container rather than 3d printing a hopper. It was though that it would be smoother (which it was) and could be cut to the right size.
In testing it seems that a full bottle can hold more than enough rice to half fill each of the three containers in a single run.
Weight wise the attachment seems strong enough to hold it and the robot seems stable as long its not driven and stopped too quickly!
![](http://www.thelemmingfarm.uk/wp-content/uploads/2022/06/image-1.png)