DIY DPV Motors

[merseydiver]

Hi All.

Apart from canabilising an electric outboard motor (eg. a Yamaha M20) does anyone know what types of 12 Volt electric motor are suitable for building DPVs.

Thanks in advance

Steve

 

[scubatech]

I recomend trying to find a battery powered industrial floor cleaning (buffing machine)
reason:
run on dc
are usually well constructed of corosion resistant materials.

or possibly some other form of simmilar machine.
:doctor:

 

[mmakay]

merseydiver once bubbled...
Apart from canabilising an electric outboard motor.........
[/B]

If you're looking for a reasonably simple project, that's by far your best bet. Nearly all electric motors use a mild steal for construction which would need to be perfectly sealed to last more than one dive. Given the physics of sealing a spinning shaft under pressure, that's no small bit of engineering. Add that they (electric outboards) come supplied with an appropriate prop, and you just can't loose. Trial and error finding the right prop for some mystery motor is going to set you back any money you saved in the first place.

 

[jamescaswell]

Bosch Gpa(?) 24 v 750 watt is an suitable motor for a dpv.(used in aquazepp,s).
Needs a step down gear and you neeed to source a prop for your dpv.Low rpm,s,,,3-500 revs,big prop for max thrust.
good luck
james

 

[DennisS]

If your thinking of building a DPV there are some parts over on E bay,

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1300&item=3690701619&rd=1

 

[Shaka Doug]

I would consider using a motor from an electric boat trolling motor. They are already waterproof and wired up. You could modify it quite easily. They come in various power ranges too. Do you plan on running in salt water? I am also interested in building a DPV. Do you have plans on how to do it or are you figuring it out as you go?

Aloha,

Shaka Doug

 

[PRL]

Dont have ANY experience in that field but I'm pretty sure that trolling motors are water tight only at the surface and the pressure at the expected performance depth would blow the seals in. I dont like the idea of equlizing the pressure with air and a regulator. electric motor brushes produce spark, motor is lubed with petrolium based grease, and the partial pressure of O2 at deapth could cause an explosion. I've heard of filling the motor with transmission fluid to seal it off, but I,m not sure if the temperature drop wont condense the fluid to let water in or even worse if the temperature rises it might bleed fluid into our already polluted waters

I would consider using a motor from an electric boat trolling motor. They are already waterproof and wired up. You could modify it quite easily. They come in various power ranges too. Do you plan on running in salt water? I am also interested in building a DPV. Do you have plans on how to do it or are you figuring it out as you go?

Aloha,

Shaka Doug

 

[PRL]

I dont know the specs and dont know if these sources will help you, like I said, no experience in this field. You might consider an automobile starting motor for your motor. For the seals you might be able to use hydraulic pump seals, or automobile power steering pump seals. For the output shaft cone you might use an old scuba tank neck. I wouldnt use a scuba tank for the entire case because it will probably be to heavy, but for the ends it might be worth considering.
Just thinking out loud.

 

[Buccaneer]

If you search the net you can find many plans, often for free on building dpv and open water 1 and 2 man subs. All the plans I have seen incorporate trolling motors, and all claim thier dpv's can be operated at any recreational scuba depth

for a starting point search under homebuilt submersible

 

[Gary D.]

Take a close look at some of the DPV's. They have trolling motors on them. Even some of the ROV's arer trolling motors.

Motor Guide has a smoother shaft so it is easier on O-rings than Minn Kota and a metal shaft which is easier to work with than the composite shafts.

The companies will say they are good for 1atm when diving but I have had them over 200' without problems.

A 32# thrust motor will run 1 hour on a Sears Gel Wheelchair battery.

Gary D.