Robotic Fish Kit – The Magical Use of M10 Nut

This article shares the inspiration that the M10 nut brings to ROV MAKER when optimizing the Bionic Mechanical Fish.

One of the design concern of the bionic fish is its balance in the water, which has puzzled ROV MAKRE for a while. When A bionic fish is swimming obliquely in the water, the first association is that the fish is about to die, which is a bad experience as teaching kit (except for the course that explores life and death).

By observation, the table tennis ball provides a source of buoyancy for the bionic fish and it also forms a fulcrum on the water. If the parts on both sides of the fish body weigh on one side or provide too much buoyancy relative to the other side in the water, the fish body will tilt towards one side with the ping-pong ball as a fulcrum.

We weighed the related parts of the mechanical fish body.

TT-Gear-weighting  Battery-wighting-1 Battery-weighting-2

After the comparison, it was found that the weight of batteries of different brands is different. In addition, the battery box will increase the buoyancy after the balloon is put on, and the lighter battery will make the fish tilt more obviously in the water.

Teams with mature commercial product experience will immediately think that this is a lack of design and try to improve. The most intuitive way is to think about how to move these parts in the position of the fish body to improve.

An M10 nut that just fits on the work table and gave ROV MAKER a new inspiration.

Although the bionic fish is a commodity, it is also a teaching kit. Instead of being perfectly designed to avoid the fish from tilting in the water, it should tell students that they encounter this problem, understand the reasons, and find feasible solutions for improvement.

The ballast method of general ships can be used as a reference. The ballast tank of a ship is a tank in which ballast water is placed to adjust the position of the center of gravity, float and stability of the ship. It can solve the problems of insufficient stability or inappropriate draft caused by oil and water consumption and elevated center of gravity of ships during sailing.


ballast tank

After weighing, the weight of the M10 nut can be used as the ballast of the bionic fish (if you regard the bionic fish as a twisting boat), and its size is acceptable.

M10 Nut M10 Nut Weighing

The placement of the M10 nuts is also an interesting topic to discuss. At present, it is planned to be placed, the vertical direction is at the bottom of the fish body, and the horizontal position is as close as possible to between the two table tennis balls. If the counterweight effect is not satisfactory, consider increasing the number of M10 nuts.


Painted Bionic Mechanical Fish

There are many topics that can be discussed in the bionic mechanical fish, and we will publish articles to share !!