Radio Controlled Lego Submarine

AI Thread Summary
The discussion focuses on a radio-controlled Lego submarine build, highlighting the challenges of radio control in water. The builder salvaged a toy radio controller operating at 27MHz, as higher frequencies are ineffective underwater. The submarine achieved a control range of 3 to 4 meters, with limited improvements from adjusting antenna and receiver placements. Additionally, the project involved Python coding for a Raspberry Pi and utilized a syringe mechanism for ballast control. The associated blog provides further details on the build process.
Messages
15,458
Reaction score
10,170
TL;DR Summary
Youtuber builds a cool radio controlled submarine
 
  • Love
Likes Filip Larsen
Engineering news on Phys.org
He also has an associated blog describing the build in greater detail.

https://brickexperimentchannel.wordpress.com/rc-submarine-4-0-blog-post-series/

In particular, I was curious about the radio-controlled aspect as radio-control is pretty much impossible in water. He salvaged a toy radio controller with a low-frequency transmission of 27MHz citing that very issue ie GHz wouldn't work at all.

His build was able to control the submarine at a maximum of 3 to 4 meters. Playing with antenna placement and receiver placement didn't seem to improve it all that much.

Another part of his build was the python coding for a Raspberry-Pi and the use of a syringe to control ballast.
 
Thread 'What type of toilet do I have?'
I was enrolled in an online plumbing course at Stratford University. My plumbing textbook lists four types of residential toilets: 1# upflush toilets 2# pressure assisted toilets 3# gravity-fed, rim jet toilets and 4# gravity-fed, siphon-jet toilets. I know my toilet is not an upflush toilet because my toilet is not below the sewage line, and my toilet does not have a grinder and a pump next to it to propel waste upwards. I am about 99% sure that my toilet is not a pressure assisted...
After over 25 years of engineering, designing and analyzing bolted joints, I just learned this little fact. According to ASME B1.2, Gages and Gaging for Unified Inch Screw Threads: "The no-go gage should not pass over more than three complete turns when inserted into the internal thread of the product. " 3 turns seems like way to much. I have some really critical nuts that are of standard geometry (5/8"-11 UNC 3B) and have about 4.5 threads when you account for the chamfers on either...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...

Similar threads

Back
Top