n2ghtowl

Does anybody know if i had 4 jet drives in a 4" tube all sealed from water apart from intake and cooling tubes for the motors, and a waterproofed variable power switch on outside would they work under water?
thanks in advance
Jayz

mfr02

A jet drive is a tube with a close fitting impeller inside and a motor outside the tube, but inside the boat. Effectively its under water. No reason why one should not work on a submerged vessel. Switches, speed controls and motors are best kept away from water.

n2ghtowl

Thanks, i thought it would be the case but didn't want to buy all goods and then disaster strike. any recommends for varable speed controller that could be used? i have got a rubber boot that will be compressed by o rings and the plastic tubing so would be completely water tight up to about 30m.
I am planning on making a diver propulsion vehicle, with stealing control as well as a speed control; by my reckoning the 4 motors should provide enough power to give me a top speed of about 10 knots with full scuba gear on.

alligaitor

I use a pro boat waterproof speed control in my sub... no need to waste precious waterproof real estate to keep it dry..its completely sealed.

alligaitor

I've seen DPDs made from the lower unit of a trolling motor...lots of power- no headache of mounting and waterproofing the motor/prop...just need to engineer the hull and shroud (fiberglass and foam)

mfr02

Depends on the motor, a more powerful motor will draw more current and need a controller specified to carry that current safely. The suggested performance indicates a lot of power.
It also depends on whether you pick brushed motors or brushless, you can't drive a brushless motor with a brushed control and vice-versa. Brushed motors must be kept dry. Brushless "can" be used wet if the bearings can stand up to what the water and whatever is in it does at them, and all of the bare, electrically live, metal is insulated.