Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

OK then - how about 'over the tank' (overhead) wires, running on battery power only for safety, with wires fore and aft,  from the ship's masts or other upperworks location - bit like the dodgem cars.


Just trying to keep it relatively simple...


Regards,
Ray.

or the opposite, the runner is under water and the boat is connected to the runner by a wire that guides the bow whilst the prop pushes it along, the wire is off the floor of the tank held to the sides by wire supports that bend down onto the runner, the wire from the boat goes under the wire and loops up in a definite U shape that does not touch the supports. This way of looping the wire to the runner ensures they do not become detached due to wave action, and yes 4 x 2 feet is very small, more of a fish tank than a display case.

Made some progress on the Plug over the weekend. Think i need to tidy the bench up and clean up all those cobwebs!

Sorry if I seemed to be curt but going back to the original post, the system described as usd in model displays appears to be a simple wire and magnet setup. I would think he is looking for something similar in a small tank. In which case complex electronics in craft small enough to toddle around in the average bathtub seems to be to be overcomplex engineering!

I like C3PO's idea of a transparent sheet mounted just below the surface which would be all but invisible. Building on that idea why not try using an acrylic glazing sheet (available from DiY stores) and attach an unobtrusive wire to it. The the floating craft, whatever they are, could have neodymium button magnets mounted on ther bottoms or on an extended keel if you want to keep the acrylic sheet deeper in the water. Effectively this would be the equivalant system to what he is describing in his post.

Cheap and cheerful if it works.

Colin

I am in awe @ Peter's build ability - the crane and catapult (John  R Haynes) are a work of art...



C-3PO

BTW I wouldn't use a pla printed part for a thimble, that may well distort. Definitely benefit from a metal mount, preferably with some water cooling for a fast electric.

It's nowhere near as good as yours though Dom!

Colin

Thank you, guys! 
Colin, your model is still a sight to behold. And your review is also still plenty helpful 

SKEANDHU will be available on the Bring & Buy stall at Blackpool for £225...


£25 donation will be made from the sale to the shows RNLI donations box...

Now, that is a most informative reply and helps a great deal in attempting to understand the complexity of the programming involved.
I thank you sincerely for this.


Now is a good time for me to go away and ponder over the complexities of achieving a satisfactory answer to the originators question.   


Regards,
Ray.

Arduino Boards - is it at all possible to programme these boards to follow a specific step by step route (ie rudder movement /motor speed)  and set to repeat the sequences?


... and before I get shot down with curt remarks - no, I have absolutely no idea about the capabilities of the Arduino system!


Just as a matter of interest - what dimensions of vessel is being proposed here...

Yes to Arduino can do the first bit (repeat specific steps over time - rudder/motor speed etc) but the position of the boat will need "correcting" to follow the path.

GPS is a no no - accurate to 5M if you are lucky - and tracking to a waypoint without bow/stern thrusters would be a challenge - and with them an even bigger challenge to write the PID to control the positioning corrections

Ultrasonic sensing might help a bit - you could work out how far you where from an obstacle - but would not necessarily be able to identify which object hence position

You could use "TOF" laser sensors - very accurate distance measurment but again you would still not know position

You could use some IR sensors slung under the boat tracking near the bottom of the pool to follow a black path line - but once you have lost the line unlike a robot you can't stop/pause movement immediatley whilst you re locate the line as the boats momentum will allow the boat to drift off the line

https://youtu.be/bxXyhgX3Sws?t=86

You could use 2 NEMA stepper motors,  connect to extended spindles that are located in the water to control X/Y wires on pulleys to pull the boat around - a bit like a "2D plotter" - the Arduino could control the steppers to accurately position the boat on a repeatable path

https://www.youtube.com/watch?v=gTH3VjvCfpA

C-3PO