Water Diver - 3D Printed Submarine

Hi, I'm Marcel, and this is my 3D printed submarine. Originally a project for a Science assessment, this submarine has no complicated microcontrollers or water tanks. Instead, it has wings which rotate up and down via a rotary to oscillatory mechanism. Also, the BOM (listed w/ links below) is quite simple compared to other designs, nothing that the average consumer can't get their hands on. 

Anyone can build one of these, and it's a great learning experience for people who want to learn about forces acting upon an object, along with basic soldering and assembly skills. It also teaches how to convert rotary motion to oscillatory motion, which is very helpful for designers and people who want to know more about the world. 

Note that the main body will need supports on 2 parts.

Also, if anyone can design a better propeller/impeller, I would be very grateful, as I am not good at designing propellers/impellers.

This is the Onshape document if you need a reference when building:

https://cad.onshape.com/documents/5b1f36609d8991902794f059/w/54f059acceb7408a9e62fa5a/e/b85f22523bb9121b3a307eda

BOM:

Propeller motor (500-1000rpm) https://www.amazon.com/Augiimor-Reduction-Gearwheel-Gearbox-Electric/dp/B08B39FM6V/ref=sr_1_27?crid=1K00XEFRFSNJO&keywords=geared%2Bdc%2Bmotor%2B9v&qid=1665795893&qu=eyJxc2MiOiIzLjEyIiwicXNhIjoiMi41NSIsInFzcCI6IjIuNDcifQ%3D%3D&sprefix=%2Caps%2C508&sr=8-27&th=1

Sink/Rise motors (3v 16 rpm or 6v 35rpm) https://www.amazon.com/dp/B08LL9Q7M4?ref=ppx_pop_mob_ap_share

Ball Bearings https://www.amazon.com/uxcell-MR105-2RS-Groove-Bearings-Double/dp/B082PRYJGZ/ref=sr_1_6?crid=398C8RE1Q5ZDD&keywords=uxcell+MR105-2RS+deep+Groove+Ball+Bearings+5mm+Inner+Dia&qid=1665796738&sprefix=uxcell+mr105-2rs+deep+groove+ball+bearings+5mm+inner+dia+%2Caps%2C364&sr=8-6

Switches and 9v connectors https://www.amazon.com/dp/B0B2NMWLR7?ref=ppx_pop_mob_ap_share 

Red solid core wire 22awg https://www.adafruit.com/product/288

Black solid core wire 22awg https://www.adafruit.com/product/290

Loctite glue (honestly just pick it up at Walmart) https://www.amazon.com/Loctite-Control-4-Gram-Bottle-1739050/dp/B00ELV2D0Y/ref=sr_1_3?crid=15H42QYCN3BC8&keywords=loctite+ultra+gel+control+super+glue&qid=1665797306&qu=eyJxc2MiOiIyLjg5IiwicXNhIjoiMi40NiIsInFzcCI6IjIuMjYifQ%3D%3D&s=industrial&sprefix=loctite+ultrag%2Cindustrial%2C271&sr=1-3

If you don't already don't have these, 

Soldering iron https://www.adafruit.com/product/3685

Stand for iron https://www.adafruit.com/product/150

Screwdriver Hakko head https://www.adafruit.com/product/1250

3D pen https://www.amazon.com/MYNT3D-Professional-Printing-OLED-Display/dp/B01BLQ24IW/ref=sr_1_4?crid=2P2EGZ7L3MT5B&keywords=3d+pen&qid=1665797253&qu=eyJxc2MiOiI0LjMwIiwicXNhIjoiMy44NSIsInFzcCI6IjMuNTYifQ%3D%3D&s=industrial&sprefix=3d+pe%2Cindustrial%2C350&sr=1-4&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc

Solder https://www.amazon.com/AUSTOR-60-40-Solder-Electrical-Soldering/dp/B073LHK99Z/ref=sr_1_4?crid=QXQ6IDBZSG9G&keywords=60%2F40%2Bsolder&qid=1661114378&s=industrial&sprefix=60%2F40%2Cindustrial%2C235&sr=1-4&th=1

m3 bolts https://www.amazon.com/DYWISHKEY-Pieces-Socket-Screws-Wrench/dp/B07VRC5RJ8/ref=sr_1_4?crid=3VGCI1FFQWALO&keywords=m3+bolts&qid=1665797389&qu=eyJxc2MiOiI1LjQ0IiwicXNhIjoiNC45NCIsInFzcCI6IjQuODMifQ%3D%3D&s=industrial&sprefix=m3+b%2Cindustrial%2C178&sr=1-4

Note that you will likely need to use 9v batteries for all motors, not just the propeller. This is due to there not being that much space in the hull, and the small motors not being able to output that much torque.

Instructions:

• Print it. I used PLA, as that's the only material I can print currently.  
• Post process it. My printer isn't perfect by any means, and I toleranced all parts to my needs, so you may have to post process some parts, or change how large they are in the slicer.
• Assemble the sink/rise mechanisms and bearings. The wings and the parts that drive them. It's pretty simple. The holes in some parts are for m3 bolts to fasten 2 parts together. Again, the CAD model will help with assembly and aligning parts.
• Glue Parts together. I use Loctite Ultragel Control super glue. The parts you will have to use this on are the bearings (to secure them to the prints, especially for the fixed pivots), the motors (to secure them in place and to fix them to the wheels/propeller). Note that some parts will need to be glued in later, such as the motors, which you should to after wiring. 
• Wire everything together. Push in the 6 switches into the holes and use a 3D pen to make it watertight. Then, wire each switch to the motors/9v batteries. There should be 2 switches per motor, one controlling positive and another controlling negative. Note that you should test each motor and make sure they're going in the correct direction before you solder everything together. The propeller should spin counterclockwise/the way the fillet is facing.
• Finish assembly. Put the faceplate on, and if you're confident about your wiring, seal it together using super glue/a 3D pen at the seams so nothing can leak into the hull. I'd advise doing 1 test before that to be sure about the buoyancy, as it should sink below the water. You can, alternatively, strap weights to the bottom to adjust buoyancy.
• Have some fun with it!