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SCUBA toy


(laurence) #1

Hi,

I’m thinking of making myself something for SCUBA diving with a couple of T200’s on it, something that’ll end up not costing the earth (ie SEABOBs) but better than SEADOO scooters.

As a novice at this, any suggestions as to a good battery source to power them for about an hour of use, and quick charge times?

I’m really impressed with your designs for the thrusters, well done guys!

Thanks,

Laurence


(Rusty) #2

Hi Laurence,

We’ve dreamed about doing some similar things here. It would be a lot of fun!

I definitely think the T200s are the way to go because SCUBA divers have a lot of drag and it takes a lot of thruster to move around. In terms of batteries, you’ll get the best power and endurance for the size from lithium polymer batteries. I would suggest looking at those designed for RC aircraft as a starting point.

In terms of battery size, let’s say you have two T200s (which can run at up to around 275 watts) and you want to be able to run at full power for 10 minutes, which is probably about right for an hour of SCUBA diving. That’s (2 x 275 watts) x (0.17 hours) = 93.5 watt-hours of energy. You’ll need a battery with that capacity. The power capacity of the battery is the voltage times the amp-hour capacity. For example, with a 4-cell (14.8V) lithium polymer battery, 14.8V x 7 amp-hours = 103.6 watt-hours, which is enough.

Here’s a battery that would fit those numbers pretty well:

http://www.hobbyking.com/hobbyking/store/__38502__Turnigy_7200mAh_4S_14_8V_40C_Hardcase_Pack.html

How are you planning to mount the thrusters? To the tank? Here’s a very cool freediving video for some inspiration:

Keep us posted!

  • Rusty

(laurence) #3

Thanks Rusty, just what I needed to get me planning.

I was thinking of similar to the freedive video or off the tank.

I’m also planning on doing a new kayak version as well. Would you suggest the same batteries but link a few to increase capacity?

Regards, Laurence.

 


(Rusty) #4

Laurence,

Cool. You can actually use the same battery but connect multiple batteries in parallel to increase capacity. For example, two 7.2 Ah packs will provide 14.4 Ah of current capacity. The RC batteries don’t usually come in size much bigger than 8 Ah, so it will be easiest to connect them in parallel.

-Rusty


(fernandez pascal) #5

hi

i am interested for build a seascoot like this jet boot .

but do you an idea for the control of the EsC ? Do you used an ESC by T200 OR an esc for the 2 T200 in parallel .fOR the battery , i know the lipo to used it with my RC/ CARS .

I think mounted the T200 thrusters ON EACH LEG WITH A HARNESS LIKE IN KITESURF OR WINSURF

THANKS FOR THE ANSWER


(Rusty) #6

Hi Fernandez,

You’ll need an ESC for each thruster. That could either be the Basic ESC or the BlueESC. You’ll also need a way to send a control signal to those ESCs. That part is a little more difficult. I would suggest a microcontroller like an Arduino, paired with some sort of control like a potentiometer or force sensor.

There are some potentiometers rated to 30m depth available here but they are a little expensive:

https://www.digikey.com/product-detail/en/P13SMNFGS103MA/716-1042-ND/3078705

I hope that helps.

-Rusty