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Oct 30, 2017, 03:36 PM
Latitudes vs Attitudes
Bob Gaito's Avatar
I use centrifugal pump that I got from Edmond scientific a long while back..I think Edmonds is gone but I believe the pump is still around (but any pump will do)..and a water sensor that I made from a NE555 IC chip..Please note that the diagram in post showing the Radio Shack chip and copper plates will probably cycle very quickly. I have a set-up where there are 3 electrodes (1/16 brass rods) one high to start the pump which latches in the on position, one common, one in the low position to shut off the pump. This makes sure that there is water to pump out....
I have this in my Broward- water fills a bulkheaded chamber. Then the pump goes thru its cycles to pump out to thru hull fittings P&S to give that lived in mega yacht over board dump look, cycle time is about two minutes but that's because I have a calibrated hole in the bottom of the hull-mine is just for effect.
Yes swiffer pumps are cheap-from Hong Kong-don't bother taking a used swiffer apart you can get them for 3 bucks! But try to use a centrifugal pump that can stand where the impeller is almost touching the hull -like a real bilge pump otherwise you have to deal with intake plumbing and self priming pumps- BTW the swiffer pump is a self priming gear pump and runs at 5 to 12 volts -you might have to remove the output needle and install a hose fitting-But its all good!
PS these would work just cut off the intake nipple and mount standing up-$1.99ea.
http://www.ebay.com/bhp/mini-water-pump
Last edited by Bob Gaito; Oct 30, 2017 at 03:57 PM.
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Jun 02, 2018, 04:55 PM
Registered User

Swiffer pump


Quote:
Originally Posted by Bob Gaito
I use centrifugal pump that I got from Edmond scientific a long while back..I think Edmonds is gone but I believe the pump is still around (but any pump will do)..and a water sensor that I made from a NE555 IC chip..Please note that the diagram in post showing the Radio Shack chip and copper plates will probably cycle very quickly. I have a set-up where there are 3 electrodes (1/16 brass rods) one high to start the pump which latches in the on position, one common, one in the low position to shut off the pump. This makes sure that there is water to pump out....
I have this in my Broward- water fills a bulkheaded chamber. Then the pump goes thru its cycles to pump out to thru hull fittings P&S to give that lived in mega yacht over board dump look, cycle time is about two minutes but that's because I have a calibrated hole in the bottom of the hull-mine is just for effect.
Yes swiffer pumps are cheap-from Hong Kong-don't bother taking a used swiffer apart you can get them for 3 bucks! But try to use a centrifugal pump that can stand where the impeller is almost touching the hull -like a real bilge pump otherwise you have to deal with intake plumbing and self priming pumps- BTW the swiffer pump is a self priming gear pump and runs at 5 to 12 volts -you might have to remove the output needle and install a hose fitting-But its all good!
PS these would work just cut off the intake nipple and mount standing up-$1.99ea.
http://www.ebay.com/bhp/mini-water-pump
Do you have the link for the $3 swiffer pumps? I'm looking for a cheap pump that I can use as a bilge pump for a boat I'm building.
Jun 21, 2018, 09:18 PM
Registered User
royalcasa's Avatar
Quote:
Originally Posted by Bob Gaito
That link is highlighted in blue in the quote you just posted-go about 3/4 down on the page and it looks like this:
Can this pumps be used for cooling motors / ESC. Or will they burn up running long periods of time
Jun 23, 2018, 09:56 PM
Latitudes vs Attitudes
Bob Gaito's Avatar
they are used in swiffer wet mops and I think Kureg coffee makers...at 5 or less volts I think theyll run all day-but I like the idea of tying them into the esc so they don't run all the time.-it's not like there is any load on them..the white plastic pumps are aquarium pumps (long duty) but they are not gear pumps they are centrifugal (not self priming must be mounted below waterline and an intake manifold must fabricated for piped intake because they are designed to be submerged(more like a bilge pump)
Sep 01, 2021, 03:13 PM
Registered User
If you only need to pump a small amount that gets into the sump, why not use a tube that faces to the rear of the boat that would pull a suction as the boat travels forward? See sketch. Has anyone tried this?
Sep 01, 2021, 05:32 PM
Latitudes vs Attitudes
Bob Gaito's Avatar
Quote:
Originally Posted by eganders
If you only need to pump a small amount that gets into the sump, why not use a tube that faces to the rear of the boat that would pull a suction as the boat travels forward? See sketch. Has anyone tried this?
Yes its been done- the 1:1 Century Sea Maid ...in the model world not so much...

Great revisit for models ..I hope it catches on ... again-BG

eganders. are you sure you weren't Bernoulli in a past life?
Last edited by Bob Gaito; Sep 01, 2021 at 05:38 PM.
Sep 06, 2021, 09:30 PM
Registered User
I am afraid that I can't claim to be a Bernoulli guru. I tried the concept shown in my sketch, and unless I have done something wrong, it does not work as I had hoped.
I tried to find the Century Sea Maid self bailing design, and so far, no dice. I cannot find it..

A water powered sump pump (I have one) sort of uses this principle. If someone can point me to the Century Sea Maid self bailer design, I would sure like to see it.
Sep 07, 2021, 07:04 PM
Latitudes vs Attitudes
Bob Gaito's Avatar
Sorry man I spent an hour looking I couldn't find it and I don't remember exactly where I saw it... It was basically what you drew in the above post.. I'm pretty sure it was related to the Sea made thread by Graveman... It might be in a related but separate thread which I cannot remember the name of.
Sep 07, 2021, 07:07 PM
Latitudes vs Attitudes
Bob Gaito's Avatar
I would try putting the AFT facing outlet in back of a propeller and make sure that the water lock barely comes above the water line otherwise it might not have enough suction to lift the water that high.
Sep 10, 2021, 11:10 AM
Big Boats Rule!
boater_dave's Avatar
The siphon hose type of bilge drain works for boats that don't go in reverse. Using direct prop wash to increase the suction is a good idea. And the higher above the waterline the loop goes, the more suction you will require. The best setup would have a one way valve to prevent water from coming back in. But if you have a one way valve, you don't need the loop. But it is a devise with moving parts below the water line. Made popular by gas boat go-fast types that never back up.

If you have a big scale boat, with lots of water in the bilge, a pump would be best. No under water fittings required. Engage the pump when needed. Or, fix the leak.


Dave
Sep 30, 2021, 04:16 AM
Durability Tester
these little diaphragm pumps are self priming so will suck the water up and out the bilge, you just need to make sure to add a small fuel filter or something to the intake as they are sensitive to debris.
https://www.ebay.co.uk/itm/174408382717
Oct 05, 2021, 07:13 PM
Registered User
Have used those little diaphragm pumps for about 5+ years to supply cooling water to my ESC cooling and brushless motor water jacket. My scale boats don't run fast enough to push water through the hull pickup fittings, but the diaphragm pumps work just fine and supply a steady stream of water. They typically suggest 12 volts DC to run these pumps, but they tend to perform much better between 8-10 volts DC. I use a buck/boost voltage regulator to maintain a constant 9.5 volts to the pump motor. This will allow me to use different battery pack voltages without any pump voltage issues. The pump can be activated either by use of a receiver powered relay or Aux electronic switch. Keep in mind that the diaphragm pump does not provide as much head pressure as a gear pump - so keep the outlet fitting as low as possible - but above the water line so that you can see the flow. By its design, the diaphragm pump will run for ever and not leak, until the diaphragm tears or cracks - at least 10 years of service. However a gear pump has the motor shaft going through an O ring seal directly into the drive gear. I've found that a gear pump does not have a very good operational life before the seal fails. This is especially true for a Sullivan gear pump, which has lots of output pressure and can lift at least 12". It's a great pump for a fire monitor, but its operational life is 2-3 hours before the seal starts to leak. I have found that using a bi-metal sensor switch for a water level control works on for a short while until the electrodes get corroded (RAM bilge pump) My best bilge pump level control was a micro float switch connected to the control side of a power relay. By bad experience I have found that bilge water switch and full battery pack voltage don't mix. A failed float switch - or bi-metal sensor switch will drain your main battery pack in a heart beat. It's always best to able to isolate your battery to pump voltage by a relay or electronic switch. I'm not sure how the warship guys rig their bilge pumps, but they really need them when the hull gets holed with shot. Most likely they use a completely different battery system to run their pumps and separate them from propulsion and gun control systems.
Oct 05, 2021, 10:28 PM
Durability Tester
Quote:
Originally Posted by tebby2
Have used those little diaphragm pumps for about 5+ years to supply cooling water to my ESC cooling and brushless motor water jacket. My scale boats don't run fast enough to push water through the hull pickup fittings, but the diaphragm pumps work just fine and supply a steady stream of water. They typically suggest 12 volts DC to run these pumps, but they tend to perform much better between 8-10 volts DC. I use a buck/boost voltage regulator to maintain a constant 9.5 volts to the pump motor. This will allow me to use different battery pack voltages without any pump voltage issues. The pump can be activated either by use of a receiver powered relay or Aux electronic switch. Keep in mind that the diaphragm pump does not provide as much head pressure as a gear pump - so keep the outlet fitting as low as possible - but above the water line so that you can see the flow. By its design, the diaphragm pump will run for ever and not leak, until the diaphragm tears or cracks - at least 10 years of service. However a gear pump has the motor shaft going through an O ring seal directly into the drive gear. I've found that a gear pump does not have a very good operational life before the seal fails. This is especially true for a Sullivan gear pump, which has lots of output pressure and can lift at least 12". It's a great pump for a fire monitor, but its operational life is 2-3 hours before the seal starts to leak. I have found that using a bi-metal sensor switch for a water level control works on for a short while until the electrodes get corroded (RAM bilge pump) My best bilge pump level control was a micro float switch connected to the control side of a power relay. By bad experience I have found that bilge water switch and full battery pack voltage don't mix. A failed float switch - or bi-metal sensor switch will drain your main battery pack in a heart beat. It's always best to able to isolate your battery to pump voltage by a relay or electronic switch. I'm not sure how the warship guys rig their bilge pumps, but they really need them when the hull gets holed with shot. Most likely they use a completely different battery system to run their pumps and separate them from propulsion and gun control systems.
I am building an 1m autonomous sailing boat that will be on its own for long periods of time so a working bilge pump will be critical, my current plan is simply a pair of pumps, that should give enough capacity to deal with anything short of the deck coming off and it will give some redundancy if one fails.
to operate them im going to use a rain sensor module with some stainless rod thats more corrosion resistant instead of the stock rain sensor, so if it detects a conductive path between the probes it turns the pump on and sends me an alert. I might stagger the probes so one is slightly above the other so the second pump only comes on if the first pump cant cope. the pump i linked to can put out almost 30psi of pressure so you dont have to worry about head height, it will push it up several meters easily. now that i think about it the pump i linked to isnt technically a diaphragm pump its a 6 piston pump with valves like a mini pressure washer pump, thats why it can put out so much pressure but its why its so debris sensitive.

i am not that worried about overheating the pumps, they are for emergency use only, if they are ever needed i want them going as fast as they can. normally they will only overheat after very long periods of time at 12v, if i need to run the pump for that long i have far bigger problems than long term wear on a pump.



https://www.ebay.co.uk/itm/154482405810
https://www.ebay.co.uk/itm/224372484519
https://www.ebay.co.uk/itm/121918945706
Last edited by geofrancis; Oct 05, 2021 at 10:57 PM.


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