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OK, I've put in a scaleauto sc-07 motor into my car and it's going VERY fast... Just how I like it.


Trouble is, my 45ohm controller makes it uncontrollable and I'm getting that 'twitchy' feeling when I raced it last night.

I used John Secci's'controller with a hundred dials'
and he manages to best this beast so it is drivable again. Kudos to him!

Anyone else try the sc-07 35,000 rpm motor (The car is non-magnet BTW)? What Ohms did you find you ended up using to keep this under control? Or did you choke your controller and run lower volts maybe? Maybe something else?

I cannot remember the pinion and crown settings I used... Suspect it's 9~27 (3-1) but it might not be....
 

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ahhh , the Satan motor


With my 35 ohm Parma it was pants , but I had alot more control when I used
my Professor Motor

However alot of power supplys are not upto the job of that motor (but sounds
like yours is) - as for gear ratios I tried going for higher acceleration/slow top
end with the thought "the motor being so good will give me the same top end
but I will get awesome acceleration" - how WRONG could I have been.

Yes I did get the same , if not more top end than before (it was a Slot.it 25k)
however the acceleration was so fearce i could not drive the corners correctly.

In the end had to tune it down - can't remember what to 2.4(ish) ratio seems
to ring a bell , I then had control in the corners , awesome acceleration and
amazing top end.

Then I put a Slot.it 29k in and left it like that. Why ? , simply more drivable - whilst
I could do a quicker lap with the scaleauto motor I could not do it consistently (might be me or the style of track) - so over a race distance I was quicker
with the slot.it motor.

All this was in a Slot.it Audi WITHOUT Magnets.
I suspect with magents it would have been a different story and the Scaleauto
motor would have rocked.
 

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I can't believe I'm having to use a 60 ohm controller to get some control back in corners with this monster.

i wouldn't have even tried to use 35 ohm on this motor, must have felt like a switch...
 

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Using a 60 ohm controller? That doesn't sound right. If it's really a serious motor and you have a good power supply then I'd thought a 15 ohm controller would be closer to what you should be using. Certainly not the other way.
 

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I must confess I'm having trouble getting my head around it too... 60 ohms.... Odd...

But I quote:

QUOTE If the resistor value is too low, the controller will work like an on/off switch.
If the value is too high, the car wont move until the trigger gets close to full throttle, so you have to
drive the car with only the last little bit of trigger travel.

I was using a 45ohm controller. I seem to recall it was more like a switch...

Oh noes! Did I get the wrong resistor???? This is the motor:

QUOTE The last motor of this series is the scaleauto SC-07, offering the highest performing test. Short Mabuchi type motor. As per the manufacturers, it offers 35.000 rpm, has a torque of 190 gr/cm and the consumption is of 0,44 A.

Turning in empty on the testing bench at 12 V, the SC07 gives us 33.330 rpm and 40.560 at 14,5 V !!. This data indicates that we are facing a motor only suitable for magnetics and very expert fingers.

So What ohms resistor should I be using??!??!?!?!?
 

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too little resistance will give huge initial acceleration. on/off
too much resistance nothing will happen until near full throttle. on/off

suggest a professor motor controller.

or get 15, 25, 35 ohm resistors and find what works for you.

running this motor in a strongly magneted car i used 25 ohm parma.
w/out magnet seems 35 or 45 ohm would work.
 

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QUOTE (djini_hades @ 8 Sep 2004, 13:52)i wouldn't have even tried to use 35 ohm on this motor, must have felt like a switch...
you think 35 ohm is like a switch i have to use 7ohm with my prma motored toyota gt1
 

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Graham Windle
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All this confusion about ohmage .With an electronic or a diode control you dont have to worry about resistance and all your motors will run on the one control. I have used the same home made control for 20 yrs with motors ranging from scalex to strap .I know a lot of people on this forum have voiced negative opinions over electronic controls and black boxes etc being deemed as expensive artificial driver aids ,sure it is a driver aid but its the most cost efective thing you can ever buy , if it costs you a hundred pounds to buy an electronic control and you use it for 5 yrs thats 20 pounds a year for control , thats not a great expense ,and as you progress in the hobby chances are your controller will last as mine has , plus you dont need a box full of different ones for all your cars.
my recomendation is buy the best adjustable you can afford its worth it in the long run
(puts soap box away and goes to work)
 

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I have got a Scaleauto SC-07 which I put in my magnet car on a twisty track but it didn't work very well round the corners. I will try it out on my long straight track on the weekend maybe-a lot more straights and hardly any corners. I was using a normal Scalextric stock controller.
 

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Discussion Starter · #11 ·
I think I'll just put some inline resistance in the controller...

3 Ohm variable should do it... But what Wattage? Anyone know how much Watts go through these controllers? I'm *assuming* <1w

NB: By 'Inline' I mean on the 'white wire' or 'Positive'. Cut the white wire and put the Pot(entiometer) in between Like this:



So... Can anyone tell me what wattage the Pot should be insted?

. o O ( I'm going around in circles here! )
 

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Discussion Starter · #12 ·
I can happily report back some figures in case anyone is interested...

I never needed to go above 3 OMS resistance of either brake or 'Choke' circuits at this weekend's Pendle track race, and would recommend not going any higher than 5 OMS max on your Potentiometers (I barely touched the 20 OMS pots to get my required rating) when you choose to buy them to keep their 'resolution' suitable.

FYI I used a SC-07 35k. 35 Oms control resistance (could have benefitted from a 30 or even 25 I suspect), 3 Oms resistance on my power line to stop the controller 'twitching' and about 1 Oms resistance on the brakes to get the car looser in the turns.

9 pin and 'blue' (26?) slot.it crown in an inline configuration with about 5 g weight in 2 x 2.5g blobs behind each wheel conpleted my Slot.it Porsche 956 car. Extra deep guide , gom ultra-low profile tyres superglued to make them slippery too of course!

I ended up soaking my P2 tyres too long however on Sunday creating astronomical grip which caused problems for me in my first 3 heats (Black, Red, Blue), finally the hardening tyres (Didn't oil them the whole day after that!)matched the steadily increasing track grip for white and yellow, giving me a personal fastest race lap of the day (8:49 secs in Yellow) to my practice fastest lap of 8:19 (Red lane).

I scored 22nd in the heats, 23rd after the final... I left London for the trip up with hopeds of getting into the top 30 this year... Not unrealistic for someone who has only been racing for 1 1/2 years... Needless to say I'm happy with the result.

Next year? V12 I think (The SC07 gives a marvelous advantage but it's untimately too uncontrollable), and aim to get in the top 20 drivers... It'll take some hard work.

Pendle Porsche challenge is definately a 'top 10 races to do before you die' event... Massive thanks to the hosts for making my first 'out of my home track' race so enjoyable!
 

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ah someone else who finally says the SC-07 is fantastic,but just not driveable
enough.

I compare to trying to drive a 275bhp front wheel drive car - alot of fun , but
you don't really get anywhere !
 

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Ric Woods
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I raced one at Wrexham in a Proslot Ferrari 360 with a 45 ohm controller. I did make sure I drank a lot of coffee, though, which seemed to work.

Mooster
 

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I agree with Graham, if you race regularly go for an electronic controller.
I know they can be expensive but they are generally well built and will last a long, long time.
If you are a bit handy with the soldering iron you could always build one for yourself even using an existing handle that you might have, i built a simple electronic [without brake resistors or full power choke] out of spare bits i had and a discarded Red Fox handle and frame, it probably cost me about £15 in total and it's OK with anything from a Scalex to Eurosports!
[oneofwos]
 

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Discussion Starter · #16 ·
Well John... I'll talk to you about it when I see you next.

Those Electronic controls:- I can't get used to them... Might try and build one though for a laugh...

I dunno tho'... I *like* my transistor Parma... I think it'll take some convincing to make me loosen my grip on it


When you goinna come down to Wood Green next John???
 

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If you do decide to go for an electronic then go for one that has a seperate sensitivity pot that way you can adjust to suit all the motors you are lickly to use including the hotter group motors. It's also worth having a brake and choke box that's either wired into the controller or in a seperate plug in unit, this is most useful when driving them there "hot" motors but try and get one that's that has resistor value's more suited to Scalex cars as the units sold are generally made for BSCRA type racing which require different value's.
Yes, i must try and pay a visit to WoodGreen because as you well know i am pretty useless on that track but i do enjoy mixing with some of the racers there.

[oneofwos]
 
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Rob reported back that he was using 15ohms, full brakes and 10/28 gearing at Pendle with a 35k (sc07) and finished 12th I think it was.

Baz
 

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Discussion Starter · #19 ·
15ohms! Dammit... Wish I took a lower OHM resistor too... I ended up taking a 60, 45, and 35 resistor, and used the lowest one... Figured I should have been going lower than that, but 15 is a supprise...

At least this explains how some people managed to control these monsterous motors on the track... Thanks for letting me know Baz
 
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