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Discussion Starter · #1 ·
hi! ive read a USA article a while back,and it states that a top open cobalt strap motor F/C on 12volts can use in excess of 320amps when you hit the trigger what sort of batteries would you use for this phenominally high amperage. cheers john
 

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Living the Life!
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oh .... that would be a girt big un
 

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It would be interesting to know how that 320amps figure was measured, or perhaps it was just calculated and not measured?

I've seen the currents for similar spec top open cobalt strap motor measured on a circuit rather than a drag strip using a storage scope and current probe and the currents measured were much lower than that.
 

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Discussion Starter · #5 ·
i believe it was read of an amp meter by one of the company guys at kofords, i,l try and track down the article, it was about a year ago i read it, it might even have been micky vegas.cheers john.
 

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Steven Dudley
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This is how,



Bulldog RDC Slot 16.4 Volts /80 Amp on each lane, with one 4 Farads capacitor on each lane.

Cheers

Steve D
 

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A decent car battery or two would be enough to do whatever you want with any sort of slot car motor... amp hour ratings taken into account.

It would be a LOT cheaper than a stack of electric parts wired together.... a LOT more reliable too. You'd have some trouble venting gases maybe.....
 

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QUOTE (cliffmanley @ 7 Jun 2011, 20:12) <{POST_SNAPBACK}>A decent car battery or two would be enough to do whatever you want with any sort of slot car motor... amp hour ratings taken into account.

It would be a LOT cheaper than a stack of electric parts wired together.... a LOT more reliable too. You'd have some trouble venting gases maybe.....
Most of the circuit racing clubs who run the quicker cars have now replaced their batteries with regulated high current power supplies.
In practice the power supplies are generally reliable, which compared well with batteries only lasting a few years at most.

A few clubs run batteries with sophisticated charging systems, that also works well. That sort of charging system isn't all that much cheaper than power supplies they'd need to dispense with the batteries, so the total costs don't work out any cheaper.

Looks like the drag guys have come to similar conclusions.
 

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QUOTE Sorry, WHAT the hell is this motor.

My 46000 rpm pulls about 6-8 amps

What on earth pulls 320amp?

Hi

Steve and 300SLR described the power situation on today's scale dragstrips accurately, 2 big truck batteries + a fleet charger gave the same amps potential at 16v in the past but were not consitant, also security was a possible issue as they did explode, today most tracks get the Rivergate power supplies + big caps and are geting good ETs with consistency.

Wraith the drag G7 motors do pull over 300 amps each at lounch, this has been mesured with lab equipment at Koford's and other manufacturers, drops down to 100a by finish line.
Oversise multi segment cobalt mags in wrap around billet cans, .004 gap each side to raise gauss, typically 43 winds (14 turns of 23 gauge wire) on perfectly balanced .450 dia arms, that's how.

High speed on such cars is 110 to 120mph on a high power track, so at 12x52 gear on a 1'' rear wheel with 20% tyre growth, top motor rpm is in the 200 000 region.

These are also expensive and tricky but facinating when they work

Cheers

Fred
 

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Thanks for the info Fred
What armature stack length are they typically using?

Interesting comparison with quick circuit racers, the quickest 1/24 cars typically run 25 gauge arms - most of them around 19 to 22 turns 0n 0.480 diameter arms with 0.300 stack length.
 

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QUOTE High speed on such cars is 110 to 120mph on a high power track, so at 12x52 gear on a 1'' rear wheel with 20% tyre growth, top motor rpm is in the 200 000 region.
and here's me thinking that the Hadron Collider was bloody dangerous .........
 

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QUOTE Thanks for the info Fred
What armature stack length are they typically using?

Well there are no rules but stacks are usualy .380, wide enough to use a lot of magnet but small enough to keep inertia down, Eurosport opens get close in wire size but much narrower stacks than we do.

Cheers
Fred
 

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QUOTE (GregK @ 8 Jun 2011, 21:51) <{POST_SNAPBACK}>and here's me thinking that the Hadron Collider was bloody dangerous .........


At least they run the Hadron Collider underground, just in case something goes wrong.

Cue the phrase: "Well that's drag racin'"
 
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