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Mech Update #18 - Test #04

A project log for 2021 HDP Dream Team: EJA

Learn more about Team EJA's intelligent buoy, and how their solution will help the global fight against ghost gear.

ekEK 09/27/2020 at 01:473 Comments

Note: The content in this log was from Sept. 14

With all of the pieces printed now, it is time to assemble and test the final prototype release mechanism!

Objectives of the test

The release mechanism concept worked! Check it out:

Here’s what the setup looked like:

Let’s begin from the start. The release mechanism and intelligent buoy are ready! Into the water it goes. It’s cool to notice in this gif how the water fills the infill of the 3D prints:

Here was the first try. The wipers don’t quite make contact with each other enough to move:

No problem, time to set it up again:

Sometimes the descent into the water can detach it:

By the way, at this point it’s probably important to point out that there’s water in the buoy. …...THERE’S WATER (!!!) IN THE BUOY!

The next test worked flawlessly:

Slow motion:

Moved the release mechanism to a deeper location, and it works again!

At this point, the water in the buoy prevented the servo from working further. That concludes this test, and we verified that this works!

What changed

The previous test #03 verified that the external wiper can remain in place, even with some faster water current conditions. With this, it was time to proceed with the release mechanism idea. 

The release mechanism is built on the top plate of the spool box design, milled out of HDPE. This piece was milled at the DesignLab and shipped here (along with some cut Nalgenes and more prints and gear! Thanks DesignLab!). 

Inside of the buoy, the only piece that changed was the internal wiper - it was re-printed a bit stronger so that it replaced the hot-glued piece.

What worked

What didn’t work

Interestingly enough, the water did not ruin the electronics! After drying, everything still worked. 

There were a few pieces that changed from the CAD model to the As-Built model. 

What needs to change for future version

The most important thing: The servo needs to home itself to -90 degrees. This is because we don’t want the external wiper to fall ‘northward’, because it could snag on the rope that is attached to the buoy. By homing at -90, then having the servo move to +90, it would increase the likelihood of the external wiper falling ‘southward’ - because the servo would never be moving ‘northward’. The Nalgene is registered such that the lid is always ‘eastward’.

With the timing of this test and the conclusion of the official Hackaday Prize Dream Team program, this is likely the last test for now. Let’s see in the future how this will evolve and hopefully continue!

Discussions

PeeVeePranav wrote 05/13/2023 at 12:27 point

Hey, such an awesome project, I have also been working on a similar idea but its a much more simplistic buoy that acts as a communication relay between two objects, I wanted to put a request asking if you can share the CAD of your release mechanism? Will be glad if you can help, thank you

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John Opsahl wrote 10/01/2020 at 18:27 point

Very clever to have the electronics rise to the surface so you can transmit a signal. Fun to watch it in action.

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EK wrote 12/16/2020 at 15:02 point

Thanks!

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