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DPV thread... gearbox and bigger prop for T200


(Lance) #1

I am seeing a lot of inquires about using the T200 for a dive scooter. From my own experience with scooters and diving and the specs on the thruster, it would be rather anemic. However, the motor itself seems more than adequate and I love that it is a wet design (all my dive electronics and custom boat crap is wet/potted).

Has anyone experimented with gearing the motor down to drive a larger prop to get more thrust? Also since it is a relatively affordable motor I’m thinking of doing a dual prop design to cut down on torque and diver fatigue from having to horse one big prop around, possibly driving two props off one motor?

The potting/waterproofing/switching/electronics is not a problem for me, I already build deep water stuff but I haven’t tried to drive props before…

Thanks.


(Lance) #2

I was able to talk to one of the engineers yesterday when I picked up parts (Thanks, Adam!)…

So, project is changing… I didn’t realize the motor is built into the T200 housing, and left instead with the M200 motor and will be gearing it down to turn a significantly larger prop with more surface area.

Gearing will be something to figure out but I’ll probably go with nylon herrringbone gears made with my trusty old Airwolf 3d printer.

Next major consideration is the prop. With some prompting I did look into using aircraft props in water (interesting discussion here: https://forum.openrov.com/t/using-rc-airplane-props-in-water/41). However, when I look at the higher end DPV’s out there, the props are what you’d expect for purpose built designs–very large surface area to stay somewhat compact but move a lot of water at a much lower RPM than say an airplane prop… not really anything like an aircraft prop or boat prop… Also possible to buy existing DPV props but ugh the cost… Now I’m kinda just thinking to 3D print a prop that I like, hand finish the surface, make silicone mold then cast in urethane so it holds up to actual use.

From there I’ll try different gear ratios and set-ups to mate that particular prop to the M200.


#3

I am working on a dual M200 DPV/ motorized camera. I use the thruster commander and a 3" battery tube with battery. Waiting for some parts for the moment… Hope to see what you come up with :slight_smile:


(Lance) #4

Thanks! Yes, my DPV is ultimately intended for film applications as well.

I have paused on the DPV and been working on a programmable dive heart rate logger system as POC and mechanical design test for the arduino (I have potted lots of solid state batteries, LEDs, and driver components with success but so far not a full arduino). Needed to work out a tiny sealed USB access port, which I think I’ve got. I am using several adafruit components for it as well as the BR depth sensor. I got the parts all talking together and software written, printed a housing put everything inside and then when I did a final test prior to potting discovered that something went goofy with the USB data connection so now have to cut wires and reconnect a new ardiuno.

For the DPV I did some research, and talked to some diver engineer friends–I am going with the old Tekna prop for my application but still planning to gear the motor down.


#5


This is the setup, just need to attach it to a frame with camera mount…