Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: possibly stupid fuse question  (Read 3944 times)

agemax

  • Guest
possibly stupid fuse question
« on: September 17, 2011, 04:48:04 PM »

RC related but its a car. i have an original tamiya grasshopper which i am hopping up and restoring. i have bought some new battery connector cables to replace the original as they were chaffed through to the wire.
my question is, the battery has an inline 10amp fuse but it is on the negative cable to the battery, is this correct as i would assume it goes on the positive side? {:-{
Logged

Netleyned

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 8,945
  • Location: Meridian Line, Mouth of the Humber
    • cleethorpes mba
Re: possibly stupid fuse question
« Reply #1 on: September 17, 2011, 04:53:14 PM »

Normally in the pos line but the current goes in a circle so it will still protect in the neg line

Ned
Logged
Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

gribeauval

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,076
  • Tidy Bench -Tidy Mind, Messy Bench - BUSY!!
  • Location: Wakefield West Yorkshire
Re: possibly stupid fuse question
« Reply #2 on: September 17, 2011, 04:54:05 PM »

Doesn't make any difference! It is only a convention to put it in the "positive" line as convention says the current flows from pos to neg,  it really flows the other way and to be truly accurate it doesn't "flow" at all !! :-X


Mike
Logged
True Lifeboat Nutter!!

Netleyned

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 8,945
  • Location: Meridian Line, Mouth of the Humber
    • cleethorpes mba
Re: possibly stupid fuse question
« Reply #3 on: September 17, 2011, 05:07:51 PM »

Back in the good old days of thermionic valves we had electron flow
The came solid state with hole flow   %%

Ned
Logged
Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #4 on: September 17, 2011, 05:10:45 PM »

so it really dosent matter which cable i connect the in line fuse into, although i would rather use the neg as that was as it was before. strange though!
Logged

Netleyned

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 8,945
  • Location: Meridian Line, Mouth of the Humber
    • cleethorpes mba
Re: possibly stupid fuse question
« Reply #5 on: September 17, 2011, 05:46:21 PM »

A 15p fuse will protect a 20 esc
Simples

Ned
Logged
Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

malcolmfrary

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,499
  • Location: Blackpool, Lancs, UK
Re: possibly stupid fuse question
« Reply #6 on: September 18, 2011, 10:26:01 AM »

As long as there is just one battery, it doesn't make any difference.  Normally, the negative sides are connected to any chassis metalwork and the black wires are a common return.  In multi battery setups (more than one power battery and/or an RX battery) the fuses will normally live in the positive leads.  This makes thinking easier when measuring things after a fuse blowing.
Logged
"With the right tool, you can break anything" - Garfield

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #7 on: September 18, 2011, 11:57:57 AM »

there is a 7.2v battery supplying the motor and a seperate set of 4xAA batteries which supply the esc. only the 7.2v battery is fused
Logged

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 740
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: possibly stupid fuse question
« Reply #8 on: September 18, 2011, 12:14:09 PM »

If it's an original Grasshopper you're restoring, is it the mechanical speed controller you're talking about?

Even with that system would you need to carry the Rx pack of AA cells? - there used to be a seperate two-pin connector that powered the radio from the main drive battery via a BEC built into your Rx (although most radios will operate on 7.2 volts anyway).

When you put 'esc' some of us would think you were talking about an 'electronic speed control' as in solid state rather than a servo operated, wiper board and resistor type as originally supplied with early Tamiya cars.

Fuse wise, it shouldn't make any difference which line it's in as long as there is some form of protection.
Logged

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #9 on: September 18, 2011, 12:37:56 PM »

sorry, excuse my ignorance, i am new to rc . the 7.2v battery goes through the speed control servo motor and feeds the steering servo. the 4 pack AA batteries just serve the receiver, i think. it is an origonal grasshopper but has a 480 motor fitted
Logged

malcolmfrary

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,499
  • Location: Blackpool, Lancs, UK
Re: possibly stupid fuse question
« Reply #10 on: September 18, 2011, 02:02:34 PM »

The usual arrangement with a separate RX pack is that the RX pack feeds the receiver, and everything that is plugged into the receiver.  The main battery provides power for the motor via the mechanical speed control, which is worked by the speed control servo, and is usually completely separate to the rest of the electrics.
Some Electronic Speed Controls have a Battery Eliminator Circuit allowing the main battery to also supply the control part of the ESC, the RX and whatever else is plugged into the RX, and the black wires are all connected to each other.
Logged
"With the right tool, you can break anything" - Garfield

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 740
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: possibly stupid fuse question
« Reply #11 on: September 18, 2011, 02:53:08 PM »

As regards your 480 motor, there was an adaptor plate and pinion upgrade available that would allow you to fit a variety of 540 size motors to speed things up a bit.....
Logged

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #12 on: September 18, 2011, 03:03:25 PM »

As regards your 480 motor, there was an adaptor plate and pinion upgrade available that would allow you to fit a variety of 540 size motors to speed things up a bit.....
its quite fast enough for me at the moment with a 480 motor. just bought a new body shell and a kit to refurb the front suspension and steering as its a bit worn out, needs new tyres too. what oil do i use in the rear gearbox and how much do i need to put in?
cheers
Logged

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 740
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: possibly stupid fuse question
« Reply #13 on: September 18, 2011, 05:34:43 PM »

As it's an all plastic geared diff, just a wipe round each gear with some medium grease will be enough. If you can lay your hands on some Teflon laden grease so much the better.

It'll probably be plastic bushes as well , keep your eye out for a bronze bearing or better still a ball bearing kit as the ultimate upgrade.
The Grasshopper was never a  proper 'racing' machine but I used tk compete at club level with one many moons ago against some quite exotic models and it gave a reasonable account of itself. It's why I have it as my 'handle' (along with the Chinese connection)
Logged

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #14 on: September 18, 2011, 06:22:37 PM »

As it's an all plastic geared diff, just a wipe round each gear with some medium grease will be enough. If you can lay your hands on some Teflon laden grease so much the better.

It'll probably be plastic bushes as well , keep your eye out for a bronze bearing or better still a ball bearing kit as the ultimate upgrade.
The Grasshopper was never a  proper 'racing' machine but I used tk compete at club level with one many moons ago against some quite exotic models and it gave a reasonable account of itself. It's why I have it as my 'handle' (along with the Chinese connection)
cheers, it has a hole in the diff with a plug marked oil. just wondered if it had to have a certain oil level in it. new gears are cheap enough on ebay
Logged

Tug-Kenny

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,717
  • Location: Newport. S Wales
Re: possibly stupid fuse question
« Reply #15 on: September 18, 2011, 08:14:48 PM »



Although interesting as a gearbox question may I ask that you keep to the subject of Boats.


ken



Logged
Despite the high cost of living   .......... It remains popular

agemax

  • Guest
Re: possibly stupid fuse question
« Reply #16 on: September 18, 2011, 08:35:56 PM »

sorry Ken, kind of got carried away. im new to this rc stuff and im hooked, cars, boats and a hovercraft now  :-)
Logged

Tug-Kenny

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,717
  • Location: Newport. S Wales
Re: possibly stupid fuse question
« Reply #17 on: September 18, 2011, 08:54:27 PM »



No problem   :}  We like all machinery problems, so pretend it's a boat.


ken

Logged
Despite the high cost of living   .......... It remains popular
Pages: [1]   Go Up