Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: npowell28 on July 25, 2024, 12:09:50 pm

Title: Bilge pumps as propulsion
Post by: npowell28 on July 25, 2024, 12:09:50 pm
Hi,
Has anyone built a boat using bilge pumps as propulsion. I'm trying to understand how they would be controlled. I was thinking that maybe you could have 2 at the rear to propel it and 2 and the front so that it would go in reverse but don't understand how or what ESC could be used to control them?
TIA
Title: Re: Bilge pumps as propulsion
Post by: dodgy geezer on July 25, 2024, 12:55:12 pm
Any ESC can be used to control an appropriate electric motor. Small water pumps (which I presume you are talking about)  are usually powered with an obvious external brushed motor - so a brushed ESC would do fine.
Some fully-enclosed aquarium pumps seem to have odd internal brushless   mechanisms. I don't know what they all do, but if you have a two-wire input I would experiment with a brushed ESC...
I doubt that these pumps would provide much in the way of thrust, however...
Title: Re: Bilge pumps as propulsion
Post by: tonyH on July 25, 2024, 01:21:41 pm
Depends on what sort of boat/ship you're thinking of. I tried one way on an experimental Thornycroft torpedo boat of the late 1800's (Look up Hydraulic Propulsion thread) Looked great but poor engineering on my part led to rotten control on the wet stuff. Neil was working on a jet propulsion lifeboat of the same period and there's a thread somewhere on here - look up jet propulsion?I think some of the bait boats may use the system?
Good Luck
Tony :-))
Title: Re: Bilge pumps as propulsion
Post by: Martin (Admin) on July 25, 2024, 02:05:35 pm

  ....... and they can be very noisy!
Title: Re: Bilge pumps as propulsion
Post by: Akira on July 25, 2024, 11:40:11 pm
Short answer, Yes it can be done.I have seen submarines( Seaview Flying sub) successfully powered by small bilge pumps.Two things to bear in mind though. Bilge pumps tend to use rather high current draw motors so the ESC needs to be similarly designed. Likewise, they can require good size batteries for any long term running. Lastly, the motors ted to be noisy, ie, EMF noise. Therefore they should be fitted with appropriate capacitors, even if you are using a 2.4 ghz radio because your neighbor may still be using a low frequency, 27, 40, 72,75 mhz radio. Depends on the country you are in...
Title: Re: Bilge pumps as propulsion
Post by: HMS Invisible on July 27, 2024, 02:27:44 pm
Hi,
Has anyone built a boat using bilge pumps as propulsion.
No,  I have not.
I have a stack of trade magazines featuring submersibles given by one former neighbour. Another former neighbour also managed a robot for cable laying.
From what I can see, the smallest industry rovs had a pair of rear mounted thrusters. I presume two thrusters were unidirectional and counter rotating for stability.
Quote
I'm trying to understand how they would be controlled. I was thinking that maybe you could have 2 at the rear to propel it and 2 and the front so that it would go in reverse but don't understand how or what ESC could be used to control them?
TIA
A single one of these toy aeroplane escs gives unidirectional but differential steering thrust for a pair of brushed motors:
https://www.ebay.co.uk/itm/186193716948 (https://www.ebay.co.uk/itm/186193716948)
You can find the aeroplanes reviewed on YouTube easily enough.