Mechanical Fish Build Progress and Test Video

Greetings Fellow Humans,

Today I am pleased to share with you the progress I have made on my Fishbowl project, a mechanical fish that will swim around it's bowl biting things. I have been working on this project off and on for a long time, and I am glad I am getting towards the end of it. It has virtually all of it's mechanical effects built, though a lot more programming is required to use one of them at all. All it really is missing aside from that is the enclosure. The fish is about 13 inches long, and is loosely based on various deep sea fish pictures I found online. It has 4 motors that power it's movements, controlled by an Arduino Mega 2560 board.

The body flexes with a series of jointed segments which oscillate along with a curved rod which keeps the fish positioned correctly. The curved rod is driven through a series of levers, rods, and cranks by a motor mounted below the fish on the support post. Pictured below is the fish dissassembled for finish work, wiring, and lubrication.

Here is the segments and curved rod that make the fish swim.

Here is the support post along with the two control rods that go through it, the swim motor, and various parts and linkages that are part of that assembly.

These are the outer body parts waiting to be ground, sanded, and colored.

After the finish work I began reassembling the fish.

Here it is all set up for testing. The breadboards clamped to the stand are for controlling the motor speed manually, since I do not have movements programmed in yet.

Here is a closer look at the lower parts. The large wiper motor at the bottom is what makes the fish circle. The 8 wire commutator in the center of the picture was an interesting challenge. I used copper pipe to make the rings, and ordered vacuum cleaner motor brushes to make contact with the rings.

And now some less technical pictures:

The mouth, circle, and swim motors are tested in the video. The fish also has an up and down motion it can do, but it is activated by a stepper motor, which requires more programming than I have done so far, so for now we will have to settle for three movements. And now, without further ado, the test video:

Thanks for reading!