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waterproofing motors — Parallax Forums

waterproofing motors

ArchiverArchiver Posts: 46,084
edited 2003-10-31 17:03 in General Discussion
I have made many!

First, the main housing can be made from PVC tubing, one end is close by a cap
(not a screwed plug) with an internal recess of 1/2 " to be grooved to accept an
"O" ring which should be compressed of 20% of it original diametre once plugged
to the cylinder housing. For the shaft end, the drive shaft of the external
propeller
can be fitted to this side plug simply by a brass or copper bushing but must be
locked
at its outside end by a collar poprevent the shaft to go in the housing, because
i.e.
if the shaft as a diameter 1/2" then at 30 feets deep the water pressure (.433
psi for every
feet of soft water) will push oto the shaft at 2.5 pounds.

This shaft if not direcly the same shaft of the motor (most likely) might be
coupled
with a rubber shaft coupler which alloud enough misenlinement of both shaft.
Avoid
rigid coupler. The whole housing can also filled in with thin oil for very deep
uses.

Have fun!

Rene Genest
Service Camera Pro.
Quebec City

Sam a

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-09-30 21:06
    Hi Sam!

    I'm sending attached files on different type of a draw I made. The hole to
    receive the bushing
    can be machined as tight enough to be put in place by "pressfit" and add some
    epoxi glue between
    the 2 surface, make the surface of the bushing rough with sand paper so the
    glue will stick better.
    an lock it with a final locking screw. For the caps at each ends, I made 2 draw,
    1 st option is to get
    the job well done by a machine shop or 2 nd option (cheaper) is to finish it
    like the back cover
    of a 35mm camera NIKONOS model V, (5) , Do not hesitate to ask machinist to get
    a more
    reliable and durable results. Electric wire can get trough cover by using
    fitting connector and plug
    normally used in compressed air industry, instead of the rigid plastic air hose,
    you place your
    electric round wire. You can secure the end cap with silicone glue or with screw
    but make sure
    to fit thoses screw on the external side of the "o" ring.

    Good luck!
    Give me back news

    Rene




    Sam a
  • ArchiverArchiver Posts: 46,084
    edited 2003-09-30 21:29
    Hi Sam I've just uploaded the draw on photo, check for motor.

    Rene

    Sam a
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-30 23:46
    does anyone have instructions on how to waterproof a motor so it's
    good down to 30ft? I don't want to use trolling motors (I've used
    them before and they aren't very efficient or light), and I don't
    want to use bilge pumps either. I've heard that one can pass the
    motor shaft though a tunnel drilled in some kind of plastic, and
    then put vaseline or something between the shaft and the walls of
    the tunnel. Does anyone have specific information about what types
    of materials to use? Good motor brands, plastic type, sealer type
    (vaseline, etc), etc. A schematic or measurements would be hugely
    appreciated. If one uses this method does it have to be constantly
    checked after each water use, or is it pretty stable of a seal?
    Thanks for any help!!
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-31 00:13
    How much torque do you need to transmit?
    Magnetic couplings can be a pretty good way to
    get power from a "wet side" to a "dry side" or
    a "low pressure" to "high pressure" side without
    any shaft seals to worry about.

    Steve


    At 03:46 PM 10/30/2003, you wrote:
    >does anyone have instructions on how to waterproof a motor so it's
    >good down to 30ft? I don't want to use trolling motors (I've used
    >them before and they aren't very efficient or light), and I don't
    >want to use bilge pumps either. I've heard that one can pass the
    >motor shaft though a tunnel drilled in some kind of plastic, and
    >then put vaseline or something between the shaft and the walls of
    >the tunnel. Does anyone have specific information about what types
    >of materials to use? Good motor brands, plastic type, sealer type
    >(vaseline, etc), etc. A schematic or measurements would be hugely
    >appreciated. If one uses this method does it have to be constantly
    >checked after each water use, or is it pretty stable of a seal?
    >Thanks for any help!!
  • ArchiverArchiver Posts: 46,084
    edited 2003-10-31 17:03
    Hi, thank you veyr much for your information. It is very helpful and
    makes sense. I have a couple questions, I have made a drawing of
    what I think you are describing, I uploaded it into the 'photos'
    section (it's on the second page of the photos section), it's
    called 'waterproof_motor.gif'. Please download it and edit it to if
    you can see anythign wrong with it. should the cap be placed at both
    ends of the pvc cylinder? If not then how is the shaft end closed?
    Also, are you saying that the seal between the copper bushing and
    the PVC around it is good enough to prevent flooding? Is there
    something wrong with my picture on the shaft side? Thanks for all
    your help!

    --- In basicstamps@yahoogroups.com, rene genest <rene.genest@q...>
    wrote:
    > I have made many!
    >
    > First, the main housing can be made from PVC tubing, one end is
    close by a cap
    > (not a screwed plug) with an internal recess of 1/2 " to be
    grooved to accept an
    > "O" ring which should be compressed of 20% of it original diametre
    once plugged
    > to the cylinder housing. For the shaft end, the drive shaft of the
    external propeller
    > can be fitted to this side plug simply by a brass or copper
    bushing but must be locked
    > at its outside end by a collar poprevent the shaft to go in the
    housing, because i.e.
    > if the shaft as a diameter 1/2" then at 30 feets deep the water
    pressure (.433 psi for every
    > feet of soft water) will push oto the shaft at 2.5 pounds.
    >
    > This shaft if not direcly the same shaft of the motor (most
    likely) might be coupled
    > with a rubber shaft coupler which alloud enough misenlinement of
    both shaft. Avoid
    > rigid coupler. The whole housing can also filled in with thin oil
    for very deep uses.
    >
    > Have fun!
    >
    > Rene Genest
    > Service Camera Pro.
    > Quebec City
    >
    > Sam a
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