Model Boat Mayhem
Mess Deck: General Section => Chit-Chat => Topic started by: Neil on December 01, 2017, 02:50:27 pm
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What brushless motor would put out the same torque and power as a mains plug in black and decker power drill please..
any ideas and could the same turning power to the motor be gained from 12v.
thank you.
neil.
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the reason for my above question!!!
as some reading this might have read in the lifeboat section I am building a water jet drive "steam" lifeboat using a centrifugal water pump.
I had seen one in aluminium for sale on ebay, but after rejoicing about the find, I read a little further and it needs machining, and I don't feel that I have the talents or equipment to do so.
However whilst looking for something in my workshop I came across a centrifugal pump that I used for pumping a flooded garden out, which is powered by clamping into the drill chuck of a mains drill. if there is a brushless with the same torque I can test it and if suitable, plumb it in to the boat.
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Neil
These are very popular for powering bait boats https://www.jabscoshop.com/marine/pumps/rule-submersible-pumps-accessories/rule-bilge-pumps/27da-rule-1100-submersible.htm (https://www.jabscoshop.com/marine/pumps/rule-submersible-pumps-accessories/rule-bilge-pumps/27da-rule-1100-submersible.htm)
There are several different outputs at 12v and you can run them from conventional brushed-motor ESCs. Just avoid the fully automatic versions which have float switches.
Dave M
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Why not use a 12v mains inverter and create 240v and just use a mains drill? All off-the-shelf parts that you know will work.
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Neil
These are very popular for powering bait boats https://www.jabscoshop.com/marine/pumps/rule-submersible-pumps-accessories/rule-bilge-pumps/27da-rule-1100-submersible.htm (https://www.jabscoshop.com/marine/pumps/rule-submersible-pumps-accessories/rule-bilge-pumps/27da-rule-1100-submersible.htm)
There are several different outputs at 12v and you can run them from conventional brushed-motor ESCs. Just avoid the fully automatic versions which have float switches.
Dave M
thanks Dave..........will it have the grunt as the pump shaft is very stiff although I might have overtightened it squashing the "O" ring...........perhaps slacken it off half a turn on each end...........also had a look at the motors on the component shop site you linked last night, and even the smallest ones are too long mate.but thanks.
will ring Stan tonight as he has some that might do.
cheers.
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Why not use a 12v mains inverter and create 240v and just use a mains drill? All off-the-shelf parts that you know will work.
its going into a model boat, plastic....55 inches by 16 inches.........don't think it'd work somehow, but thanks for the suggestion.
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just looked at the pump Dave, and I'd have to cut a hole in the bottom of the hull and then seal it well......which after my fiasco with the voiths in the ferry could end up with the first sinking lifeboat in RNLI history, lol. .........and there doesn't look a flange on the pump to seat it onto the inside of the boat.
but cheers. neil.
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Sounds easier than trying to fit an electric drill into the thing. The bait boat fraternity swear by these Rule pumps, so they must have cracked the sealing aspect. As for me well, I'd get a great big skelly-gun and a cartridge of silicon bath-sealant.........
Where's Stavros when you need him?
DM
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There is a big selection of 12v Rule bilge pumps for yachts and they are pretty efficient. They only pump in one direction of course so you might need more than one but they are not expensive. Plus they are self priming.
Colin
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cheers guys........it's just the hacking a hole into the bottom of the hull that I'm not too keen about, especially as it has a water scoop moulded into the hull.................but I'm wondering where the nearest ships chandlers is to me where I could go for a look...............but the flow of water is pretty impressive I must admit, 15 gallons a minute on 12v.......could they take 24v or even 18 to up the rate of flow......I'll ask at the nearest chandler.......going on google to look where the nearest is now. cheers.
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Just buy it online Neil!
Colin
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Hi Neil,
Being doing the calcs for the TB and the model flow rate required is theoretically based on the same formula as for the displacement of the model. I.e. if the actual flow rate (which I think is in the Graces bits) is 1 ton per second, then the scaled requirement is
2240lbs divided by (scalexscalexscale) which, if the scale is 1:12, 2240 divided by (12x12x12) = 1.3 lbs per second or approx 1 litre every 2 seconds.
That would give a scale output which was, as you know, not stunning but it could be a minimum target figure.
Hope this helps.
Tony
15 gals per minute is about 2lbs per second so you've got some in hand ok2
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Just buy it online Neil!
Colin
you know I'm of the old school Colin........I need to hold one and handle it, ponder it, imagine it in place and how its going to fit and work first.........then take the plunge.......the big problem is I have this large mound of fibre glass tunnel that is the water scoop on the original boat and is slap bang in the centre of the boat that I have to get around , and just can't envisage how I'm going to get around it by using one of these pumps until I can actually look at them.........bit of a problem unless I can find a pump that has an intake pipe as well as the outlet.................and haven't found one yet, but looking lol.........all fun of the build though........never like something that always goes like clockwork.
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thanks for that calculation Tony.....so that works out at a gallon every 8.5 seconds................that would be some going ...............might be a time to convert to one of the propeller driven boats lol...................NO !!!!!! I will not be beaten lol.
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Yes, I can appreciate your point Neil. Basically those bilge pumps sit on the bottom of the hull and when submerged pump the water away.
Maybe the best bet is to buy one and see how it fits in. The basic ones are not very expensive.
Colin
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the pump that Inertia gave me a link to shifts up to 15 gallons a minute.
you state that to get the thing going at scale would need 1ltr every 2 seconds or 1 gallon every 8.5 seconds..........which is 60 divided by 8.5 = 7.06 gallons in a minute.............so Dave's pump by your calculations would be twice what I need............could get the ol' gal plaining as fast as a Shannon yet........
so basically any submersible with those properties or one with an inlet/outlet pipe [even better for my needs] would be ample power............
thanks guys.
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Yes, I can appreciate your point Neil. Basically those bilge pumps sit on the bottom of the hull and when submerged pump the water away.
Maybe the best bet is to buy one and see how it fits in. The basic ones are not very expensive.
Colin
it's just the matter of the lump, which from the outside is a nicely "plated" scoop.......would much prefer a self primer with inlet and outlet pump, as it would be well below the water line when afloat anyway so priming would be no problem..............will have a look.
cheers..........you have all been an inspiration and great help...........not thought laterally about a simple pump before......but reckon that is the way to go rather than centrifugal job...that's just making it complicated and difficult for myself.
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If the inlet is on the face and the outlet is on the edge, the layout is relatively straightforward but that means a centrifugal one. That's what may well be under the casing! :embarrassed:
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now, although this is an automatic pump it states that if the pump is High water mode; The pump starts when the water level reaches 50mm (2")Low water mode; Turn the motor cartridge 180º and the sensor is at 33mm (1.3")
- Full Electronic mode; The pump automatically turns on every 2.5 minutes to check for water, if water is detected the pump runs until the water is gone.
- the pump would be under water at this depth constantly and would be constantly supplied, therefore wouldn't shut down.
- the intake would fit nicely into the scoop under the hull.
https://www.ebay.co.uk/itm/Rule-LoPro-Automatic-Submersible-Bilge-Pump-900-GPH-12V-Boat-Yacht-Sailing-P65/132390460312?epid=2254467822&hash=item1ed3161b98:g:ZqkAAOSwL7VWsg1f
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An automatic one will have the possible advantage that it won't run out of water, but a non auto one might be smaller and possibly cost less as well. The bearings might not be happy being run dry if too much bench testing happens. By their nature, bilge pumps are unidirectional, you don't want them sucking water in. In the old "Supermodels" series a few years back, I recall that they used a reversible pump to flood/drain HMS Fearless. The details escape me, but there might have been a drill attachment involved.
Looking at the numbers, the bilge pump motor pulls about 48 Watts (4 amps on 12 volts), well within what you might expect from a fairly ordinary 540, but a lot depends on the efficiency of the pump. Mains drills, on the other hand, tend to start at 350 Watts (memories of the old Wolf Sapphire) and work upwards, looking at the labels on B&D and Skil drills.
Looking closer at the innards of yours, I suspect it isn't truly centrifugal - it doesn't work by throwing water outwards, but the vanes in the hub get flung out and swat the water in one direction or the other. Sort of a well enclosed paddle wheel.
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Looking closer at the innards of yours, I suspect it isn't truly centrifugal - it doesn't work by throwing water outwards, but the vanes in the hub get flung out and swat the water in one direction or the other. Sort of a well enclosed paddle wheel.
Commonly known as a vain pump, inefficient due to the veins rubbing against the body, also veins can get stuck in their slots from debris in dirty water.
I would look at a high pressure 12v washer pump, some go up to 160psi, that should get you racing.
Stewart
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Hi Neil have you thought about adapting model jet drives to supply the power Bill...
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Looking closer at the innards of yours, I suspect it isn't truly centrifugal - it doesn't work by throwing water outwards, but the vanes in the hub get flung out and swat the water in one direction or the other. Sort of a well enclosed paddle wheel.
I don't think it would displace enough water outgoing anyway on looking at it so have dispensed with that pump............keep it for pumping out the garden. lol.
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Hi Neil have you thought about adapting model jet drives to supply the power Bill...
had thought about that Bill, but think a pump would be easier to connect to all the other plumbing in the boat for the jets and the valves on the jets.
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Hi Neil,
I'm afraid I'm cheating by using a pair of this type /www.ebay.co.uk/itm/800-L-H-5m-DC-12V-24V-Brushless-Motor-Water-Circulation-Centrifugal-Water-Pump/162674400908?hash=item25e0265e8c:m:mqVUsSuk8vv1f09dqLmqDSg
No idea whether it will work but I'm in the middle of soldering up the diverter valves.
Good Luck
Tony
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your link won't work tony
cheers neil.
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Here you go Neil, try this
Barrie
https://www.ebay.co.uk/itm/800-L-H-5m-DC-12V-24V-Brushless-Motor-Water-Circulation-Centrifugal-Water-Pump/162674400908?hash=item25e0265e8c:m:mqVUsSuk8vv1f09dqLmqDSg
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Sounds easier than trying to fit an electric drill into the thing. The bait boat fraternity swear by these Rule pumps, so they must have cracked the sealing aspect. As for me well, I'd get a great big skelly-gun and a cartridge of silicon bath-sealant.........
Where's Stavros when you need him?
DM
I am here and have sorted Neil out with some pumps to buy and he can use some Buller motors on their derrier so to speak as the Bullers he has got rev to around 3k which is what he needs as the all the pumps which work with an electric drill have a max rpm of 3k and they actually give a water pressure at max rpm of 3bar with an outlet of 3/8 of an inch .. Having just spoken to Neil on the old dog and bone he is a happy chappie
Dave
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thanks barrie...........sadly looking on the output they are about .25% of what I need, but Stavros has found some for me which will be perfect at 3000lph to give the boat a chance of moving.
thanks for all your help guys, and as for pumps think I'm set up........one pump per jet each driven by a Torpedo 800 and mixers from Dave [ inertia] I reckon I......................or you all, have got it sorted for me.
many thanks to every one who has offered, searched and given me advice........much appreciated.
Thought I had 4 buhlers to power the pumps....sadly only got three so will opt for the 800's
cheers all.
neil.
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Neil,
Saw this and thought of you...
Not sure I picked up on the correct thread and you have no doubt moved on from the original enquiry - but an impressive bit of kit!!!
https://www.youtube.com/watch?v=VUk_huw7iSI
C-3PO