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 bow and stern thruster control

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womble
Deck Hand
Deck Hand


Posts : 8
Join date : 2019-12-22
Age : 79
Location : Macclesfield

bow and stern thruster control Empty
PostSubject: bow and stern thruster control   bow and stern thruster control EmptyFri Jun 05, 2020 5:06 pm

Me again with bow and stern thruster problems. As per my previous topic on thrusters, I gave in and bought and fitted commercial units. All fitted, wired up, motor runs at different speeds each way! I have a fair selection of ESCs bought from eBay etc over the years, all of them give some reduction in speed in reverse. Never really realized this when used with propulsion motors, boats generally go slower in astern mode.
Any recomendations for an ESC that will deliver about 2 amp (or more) equally for small (unknown origin) brushed motor from a 12volt supply.
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barriew
Captain (moderator)
Captain (moderator)


Posts : 1990
Join date : 2011-11-26
Age : 79
Location : Thaxted, Essex

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptyFri Jun 05, 2020 5:30 pm

This Action ESC will give equal speeds in either direction. 

https://www.componentshop.co.uk/p68a-pico-1a-microcomputer-linear-acceleration-speed-controller.html

As you have found out, the cheap Chinese offerings which give forward and reverse are I think designed for land vehicle use, where differential speeds are not an issue. As you say this is not normally a problem in a boat also.

Barrie
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womble
Deck Hand
Deck Hand


Posts : 8
Join date : 2019-12-22
Age : 79
Location : Macclesfield

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptyFri Jun 05, 2020 5:53 pm

That link took me to P68a 1A Microcomputer, etc an ESC for max 6v, but I get the message thanks. You think that Action Rc electronics P81 might be my solution? Tony
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barriew
Captain (moderator)
Captain (moderator)


Posts : 1990
Join date : 2011-11-26
Age : 79
Location : Thaxted, Essex

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptySat Jun 06, 2020 7:16 am

Tony - the P78 or P81 should be OK - both will handle 12 volts. It depends on the current your motor will draw. More than 2 amps seems excessive for a bow thruster.

Barrie
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inertia
Midshipman
Midshipman
inertia

Posts : 98
Join date : 2015-02-08
Age : 68
Location : Nottingham

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptySat Jun 06, 2020 5:30 pm

Go for the P81. It will happily handle 5A all day and, as Barrie says, run the motor at the same speed in both directions. I knows 'cos I makes 'em! I am a bit concerned about running a thruster motor on 12v, though. If it's a standard 400-size motor then 7.2v is the absolute maximum, unless you like the smell of melting plastic and copious grey smoke, that is.

DM
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womble
Deck Hand
Deck Hand


Posts : 8
Join date : 2019-12-22
Age : 79
Location : Macclesfield

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptySun Jun 07, 2020 10:38 am

Thanks for the reply. I have had to fit different thrusters bow and stern because of space limitations in the cross-section of the hull. Both are Raboesch thrusters, but the bow is a 14/16 mm power 400 rated max 7.2v, which will be powered through a DC/DC convertor. The stern is a smaller 10/12 mm one with a motor rated at 6 - 12v (it is marked on the motor as well as the spec sheet that came with it.). Interestingly I agree with you that I wouldn't expect a very large current, however Raboesch recommend"speed controller marine 10 amp"!
Actually, I have sent an e-mail to info@component-shop.co.uk asking if they still supplied kits for the P78 - maybe I should have asked for kits of the P81. (They appear to be fitted with mechanical relays much like the Maplin units that I used to assemble many years ago - I fancy doing the same again).
Tony
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inertia
Midshipman
Midshipman
inertia

Posts : 98
Join date : 2015-02-08
Age : 68
Location : Nottingham

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptySun Jun 07, 2020 11:40 am

In the 2020 Component-Shop catalogue the kit for P78 is listed at £20.50 and the P81 kit is £24.00. You will need to ring or E-Mail them as it doesn't look like you can order the kits on-line. Both are fitted with mechanical relays, incidentally.

Dave M
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womble
Deck Hand
Deck Hand


Posts : 8
Join date : 2019-12-22
Age : 79
Location : Macclesfield

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptyMon Jun 08, 2020 11:05 am

to moderator, please correct my accidental spelling mistake! Title for thread "....stern....." Ta.
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barriew
Captain (moderator)
Captain (moderator)


Posts : 1990
Join date : 2011-11-26
Age : 79
Location : Thaxted, Essex

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptyMon Jun 08, 2020 12:35 pm

Done 2thumbsup

Barrie (Mod)
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womble
Deck Hand
Deck Hand


Posts : 8
Join date : 2019-12-22
Age : 79
Location : Macclesfield

bow and stern thruster control Empty
PostSubject: Re: bow and stern thruster control   bow and stern thruster control EmptyTue Jun 16, 2020 4:23 pm

Problem solved. P81s work perfectly - equal thrust each way. Thanks.
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