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Author Topic: Power to the Mighty Mo?  (Read 3352 times)

das boot

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Power to the Mighty Mo?
« on: November 18, 2008, 06:58:48 pm »
Gentlemen...which would be the correct way to wire up the Mighty Mo's motors and esc? The ESC is one of Dave@Action's P69 pico ones, motors are a pair of Mabuchi 280's.

One more question...battery pack size. Do I buy a five AA sized pack or would Sub C sized be better?

Rich
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Tug-Kenny RIP

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Re: Power to the Mighty Mo?
« Reply #1 on: November 18, 2008, 07:22:52 pm »
Hi Rich

I would not go for series wiring. Two reasons really.

One is that they would run at half speed. Secondly, should one motor stall, it would send the other motor up to fast speed. The P69 might get overloaded with the extra current.

The best advice would really be from Dave of AcTion, as mine are just thoughts.

Cheers

ken
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FullLeatherJacket

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Re: Power to the Mighty Mo?
« Reply #2 on: November 18, 2008, 07:24:57 pm »
Maybe I can be of assistance?
You can certainly use a 5-cell pack............... as long as you make sure you never recharge it.
The "terminal voltage" of the P68 PIC (i.e. the one at which it will definitely die) is 7.5v. If you fully charge a five-cell pack it will put out around 7.7v. Suit yourself, dude.
Four cells is all you need, Rich - trust me - I make the ruddy things! AA or Sub C - makes no difference to the ESC, but might sink your boat if it's too heavy.
And wire the motors in parallel, not in series.
FLJ
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das boot

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Re: Power to the Mighty Mo?
« Reply #3 on: November 18, 2008, 07:53:36 pm »
Top man FLJ...four AA cells will be the way forwards then. Question...which is series and which is parallel? I've never been able to work that one out... :embarrassed:


Rich
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craftysod

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Re: Power to the Mighty Mo?
« Reply #4 on: November 18, 2008, 07:56:52 pm »
Series is the bottom pick Rich
Mark
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das boot

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Re: Power to the Mighty Mo?
« Reply #5 on: November 18, 2008, 07:58:40 pm »
Good man Mark...

FLJ...Ken...Mark...I thank you.


Rich
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cos918

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Re: Power to the Mighty Mo?
« Reply #6 on: November 18, 2008, 09:43:22 pm »
hi rich . I have just got a load of goodes for dave (action) :-)) :-)) for 1:450 QE2. She has 2 motors and 2 ESC but i have but one of dave mixers in to help her turn , you might need this on mighty mo .

john
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das boot

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Re: Power to the Mighty Mo?
« Reply #7 on: November 19, 2008, 04:26:48 am »
That was the original plan John...two motors each independantly controlled plus rudders. Then I had my little run in with the thin blue line and it's left me....financially light, so say the least. I may still go that way though, only three weeks to pay day, then I'll probably get me another esc and do the job properly.

Any pics of the QE2 mate, sounds interesting, I'd like to see that.

Rich
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das boot

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Re: Power to the Mighty Mo?
« Reply #8 on: November 19, 2008, 08:39:19 pm »
Going back to the battery packs for the Mighty Mo...is *this* going to be ok?

*see attached pic*

Rich

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cos918

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Re: Power to the Mighty Mo?
« Reply #9 on: November 19, 2008, 10:50:50 pm »
Quote from: FullLeatherJacket on November 18, 2008, 07:24:57 pm
Maybe I can be of assistance?
You can certainly use a 5-cell pack............... as long as you make sure you never recharge it.
The "terminal voltage" of the P68 PIC (i.e. the one at which it will definitely die) is 7.5v. If you fully charge a five-cell pack it will put out around 7.7v. Suit yourself, dude.
Four cells is all you need, Rich - trust me - I make the ruddy things! AA or Sub C - makes no difference to the ESC, but might sink your boat if it's too heavy.
And wire the motors in parallel, not in series.
FLJ

hi all but sorry to but in on this thread but as i am doing a plastic kit to rc i would like to ask Dave his. normal AA bat are 1.5v each so 5 x 1.5v = 7.5v Rechargeable bats are 1.2v each so 5 x 1.2 6v. So is it ok to use a 5 cell 6v rechargeable battery on the small esc  p68 you make.

john
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FullLeatherJacket

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Re: Power to the Mighty Mo?
« Reply #10 on: November 19, 2008, 11:24:41 pm »
No.
The figure you quote is the nominal voltage i.e the one at which most of the power is supplied - but when fully charged the 5-cell pack is (or can be) up to 1.55 volts per cell. That's a bit too close for comfort. Conversely if you use 4 x Alkaline cells then there's no way in theory that the voltage can ever exceed 6.0; certainly not by enough to blow the P68's PIC.
Anyway, four cells are lighter and more compact than five......... and my mate Iain @ Component Shop doesn't need the money anyway ok2
FLJ
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das boot

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Re: Power to the Mighty Mo?
« Reply #11 on: November 20, 2008, 04:22:36 am »
Thanks FLJ...


Moresprung dosh tactic?


Rich
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FullLeatherJacket

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Re: Power to the Mighty Mo?
« Reply #12 on: November 20, 2008, 09:35:08 am »
Forgot to point out that four x rechargeables (nominal 1.2v/cell) wouldn't go higher than about 6.2v.
 
FLJ

Bedsprung Dirk Gently (you silly, silly boy........)
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das boot

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Re: Power to the Mighty Mo?
« Reply #13 on: November 20, 2008, 04:49:58 pm »
FLJ...everytime I try to buy the perishin' batteries from your mates site he's out of stock!!!    >>:-(  >:-o  Reckon I'll just have to fit the old girl with sails....  :o


Rich


( ahh...voicemail dunk deeply, then? )
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