PVSea Monster!

[FighterCat57]

I simply love all these variations on my contraption. It's giving me some ideas on the Contraption Mk2. Already in phase one is a collapsable frame for easy transport.

Yeah, I made the runners detachable and the rear pieces are for standing it upright for storage.

I'm just really hoping to get lucky enough that I'll never have to use it!

[eboat]

I have a version similar but I started with a boat

First time I just had the 2 pontoons out the front and when you got the dead boat in between it also would push it under the water So I added some wire (coat hanger) on an angle to catch the dead boat and lift it when pushing
The wire is also easy to push through the water when running empty

Had to use it twice today and it worker perfect (the other guys I run with boats :))

[Diegoboy]

I'm just really hoping to get lucky enough that I'll never have to use it!

So true. You'll be doing great if she never sees action.
Expect the best, but plan for the worst

[FE Wannabe]

Hmmm. I'm thinking a fishing line with weights and a continuous loop servo to wind them up and lift the vessel out of the water.

Basically get close, drop lines then once over the vessel, pull the lines taught and raise the vessel up almost out of the water.

Can someone point me to a continuous loop servo or how to make one?


The other approach is a series of bobbers and weights and do circles and then pull the line in taught.

FC,

Here is a LINK to a step by step guide, with pictures, to modifying a 1/4 scale Hobbico servo for continuous rotation. Most servos should be similar enough to use these directions.

I started off with a continuos rotation servo for lifting, but found when the rescue boat was far from shore I could not determine the position of the lifting basket.
In fact, if your servo is strong enough you can actually over rotate and tighten the fishing line until it collapses the PVC frame! Don't ask me how I know!

That is when I further modified the servo and installed a higher turn (10 Turn 3600 degree) potentiometer with the same ohm rating as the factory one has. I used a 10 turn pot, because I want to lower the fishing line 10 full rotations of the winch pipe which equaled about 17 inches. That is half the length of my longest boat, so nose up rescues are possible.

In case you don't know, (in laymens terms) the potentionmeter is the device inside the servo that feeds back position information.

Since this 10 turn potentiometer was a lot larger then the factory one, I had to move it outside of the servo case and attach it to the other end of the winch pipe and extend the wires to where the factory potentionmeter was wired.

Now as I lift and lower the basket with the third channel on my transmitter, I know exactly what height the basket is at all times. My third channel is set to operate linearly and has a range of -125 to +125. I know that -125 is exactly 17" below the waterline, 0 is at about 8" below the water line and +125 is 3" above water line.

Hope this is not too much detail for this thread, but do let me know if you need any more info. This was a lot of fun to design, build and test!

Brad

[FighterCat57]

For now, keeping it very simple.

Added drop wires to catch the wayward vessel. Flexible enough to bend if caught, but strong enough to push the hull, .062 wire.

Re-designed the runners, adding a step to help get on plane.

Removed the tail curl as it was creating drag.

We'll see how it does on the next pool test!

[Diegoboy]

you're probably going to need something much more substantial than that wire if the boat needing rescue is "nose up" full of water.

[FighterCat57]

you're probably going to need something much more substantial than that wire if the boat needing rescue is "nose up" full of water.

Never had a nose up full of water to rescue

[Diegoboy]

A lot of us have. Expect the best, but plan for the worst.

[FighterCat57]

The pool test to rescue the floating chlorinator was a success!
The added wires kept it pinned in place and didn't drag down the rescue boat!