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BeetleMeister

Electric speed control question

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Ok, I'm a complete dummy when it comes to these. I have never used one or even seen one fitted to a car! You may have guessed from another thread I've been posting in, that I'm looking at getting a formula car of some sort (f102, f103, f201). Am I right in thinking that you can only use a ESC with these chassis? As far as I'm aware, i'll need one sevo for steering and an ESC. The ESC works as a reciever also? Is that correct? If so, what do I do about transmiters and crystals etc? I have lots of transmitters, but what about crystals. Can I swap them over from others cars? Mechanical speedo's have a 3 step forward and reverse. What do ESC do? Some dont have reverse? Forward, brake (how does it brake? I thought reverse was brake???) and reverse? I hope someone can help me with all this as I'm pretty confused! Oh...and one last thing, if there isnt enough already. Can anyone recommend a cheep ESC that has reverse and will suit a formula car. Will probably run a stock motor or a sport tuned if this makes a difference!

Any info will be very appreciated, thanks guys [;)]

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He BeetleMeister,

An ESC is a Electronic Speed Controller nothing more nothing less.

There are several types available Forward/Brake and Forward/Brake/Reverse. if you take the last one putting the trottlestick in reverse for a short time will make the brakes active, after that the reverse will be active.

You can use the receiver you have and only need a steering servo.

As for a ESC there are a lot of cheap speedo's around maybe look for one with a 19Turn motor limit, they are cheap and you can put an faster motor in your car if you want to, but you will have to look for one wich fits your car since Formula cars do not have as much space as a Touring Car.

PS a 19Turn motor will make a F102/F103 very fast!!!!!

Hope this helped a litle!

Greatz Whacky

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Don't panic!!!

Here is how it works:

> You can only run an F-type chassis with a ESC

> Yes, you'll need 1 servo for steering & the ESC to control your speed!

> The only integral ESC/receiver that I know of is Tamiya's CPR unit.

Most people will run a good ESC (they come pretty small in size)

& a mini-receiver (or normal-size receiver if it will fit)

> Use according crystals each time (same frq. TX/RX)

> You may swap them from car to car (ideally, each car should have it's own steering servo)

> Some ESC have reverse, some don't.

> Braking is done by using battery-current to stop the motor spinning,

thus the wheels are forced to stop (except if you are using a one-way racing diff[:D])

> Reversing is NOT braking -it could make the car spin around madly!

> Duratrax has a line of affordable ESCs starting from $25 to $90.

For stock-racing I would recommend the $25 one (FWD/Brake, no Reverse). It can take motors down to 20turn -Great value! with about $50 you get the model with reverse, ABS braking & 16turn limit. Go to www.towerhobbies.com & take a look.

Word of advice: for racing only, use a FWD/Brake model, no Reverse!

Cheers,

Alex

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If you are going to get an F1 car you will need an ESC. The ESC just replaces the mechanical speed controller with an electronic one. You still need a receiver, unless you can find a Tamiya CPR unit. The ESC just plugs into you receiver like your servos do. If you are running an F1 and you fitted an MSC instead it would be very hard to drive as the car would spin out every time the speed went up each step, and as there is no braking on the MSC it would spin out whenever you tried to slow down.

Mechanical speed controllers have 3 steps, but an electronic one has smooth proportional control (although technically they have 500-1000 steps, but you won't notice them). Most high spec ESCs only have forwards and brake, this makes them much more efficient for racing purposes. If you have an ESC with reverse, while the car is going forward and you pull the throttle back the ESC will apply a brake to the motor. The harder you pull back the harder the braking is, usually these days there is some sort of ABS built in so you do not lock up the wheels. Only when the car has stopped going forwards will the ESC allow you to reverse. This means they are a lot kinder to your motor and gearbox than an MSC.

If you fit connectors to the motor leads from the ESC as well as the battery leads you can fasten the ESC down with velcro, and it can easily be moved from one car to another. Good cheap speed controls are available from Mtronks, they are reliable and waterproof and if anything goes wrong you can send it back to them easily. They have a good range. I personally prefer LRP/Nosrams, but they are a bit more pricier.

And if you want to see an ESC, heres one fitted in my touring car

http://www.tamiyaclub.com/getuserimage.asp...200290953_6.jpg

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In the U.K?

Want a cheap ESC?

Try this guy

gches@rocketmail.com

He is great to deal with and accepts paypal, shipping is really quick.

He has the Mtronics range of ESCs at good prices, just mention Simon Cook sent you...

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Thanks for all your help guys![^] <-- These new chaps are great!

Being a total novice with ESC which would you recommend for the F201? I do want reverse as I'm not racing this, just using it for fun in school playgrounds and halls (my fiance is a teacher [8D]). Are Tamiya's CRP's easily available (UK)? I bet they cost a fortune though!

Well...I need to keep this cheep so what would you guys recoomend. I'll be using a regular Acoms transmitter, servo and reciver (will it fit?), nothing flashy, just the sort you get with kit deals.

Thanks again for all your info, your a great help![:D]

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This guy I mentioned earlier has the M-Troniks Sonik3 Tempo, which is a forward and brake ESC which takes a motor down to 12turn for £29

Ones with reverse are:

Eco-27 (27t) - £20

Eco-20 (20t) - £26

Sport RV15 (15t) - £36

Sport Plus (11t) - £55

Sport Max (8t) - £80

I have Mtroniks in 3 of my cars and have no trouble with any of them, they are so easy to set up its unreal, making it very easy to move between cars....except for the fox.....Lousey dissasembling, lots of screws, mutter mutter mutter.

Si.

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Can someone please expalin the Tamiya cpr (?) to me please? Is it a speed control and receiver combined? Any good? If so, where in the UK can I get one?!

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quote:
Originally posted by BeetleMeister

Can someone please expalin the Tamiya cpr (?) to me please? Is it a speed control and receiver combined? Any good? If so, where in the UK can I get one?!

id="quote">id="quote">

Tamiya's CPR unit is indeed a RX and ESC built into 1, with a socket for a Futaba-J plug for the steering servo. Any standard AM TX will work with it.

CPRs came in various models over the years, from the original P100F up to the later P160F. We believe the numbers refer to the peak current capacity of these units... ie 100A & 160A.

CPRs used to be the most compact way to fit an RX+ESC into your Tamiya car, but these days you can get tiny separate ESCs and RXes into even less footprint.

CPRs are also "potted" whereby the entire case & electronics are sealed over and covered in epoxy. Although this is good protection from moisture and impact, it does make aftermarket repairs impossible.

CPRs also don't come cheap. You can get a full radio system and a decent modern ESC with better specs for much the same price.

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quote:
Originally posted by limas_mtb

...

> Braking is done by using battery-current to stop the motor spinning,

thus the wheels are forced to stop...

id="quote">id="quote">

Err, no. Braking on a ESC doesn't consume any battery power**.

The brake FETs simply short the spinning motor (which acts like a electric generator), and uses this electricity "back EMF" to stop the motor spinning.

The faster the motor is spinning, the more current is generated and thus the higher the 'brake' force***. Works well and is very efficient, much better than using 'reverse' to stop the car.

**ok, there a trickle of battery power required to turn the brake FETs on... but this is negligible.

***ok, also in an ideal world if calculated infinitely sans friction - a braking electric car will never ever come to a complete standstill.

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quote:The brake FETs simply short the spinning motor (which acts like a electric generator), and uses this electricity "back EMF" to stop the motor spinning.

id="quote">id="quote">

I think some ESCs for some regions of braking were even feeding the "back EMF" back to the battery, thus charging it again.

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quote:
Originally posted by DJTheo
quote:The brake FETs simply short the spinning motor (which acts like a electric generator), and uses this electricity "back EMF" to stop the motor spinning.

id="quote">id="quote">

I think some ESCs for some regions of braking were even feeding the "back EMF" back to the battery, thus charging it again.

id="quote">id="quote">

Yeah, that was back in the 80s I think...

plus a local mag (D&T!) printed something more fanciful in one April edition.

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quote:
Originally posted by gingerboy99

I have Mtroniks in 3 of my cars and have no trouble with any of them, they are so easy to set up its unreal, making it very easy to move between cars....except for the fox.....Lousey dissasembling, lots of screws, mutter mutter mutter.

Si.

id="quote">id="quote">

Just put an Eco27 in my M03 mini - it's brilliant. Took 20 mins to fit (including taking the chassis apart), 5 mins to set up (learn to read Fury :-) - should have taken 20 seconds! ) and makes driving a lot smoother. Although billed as fwd/reverse, you actually get a 2 second delay before reverse kicks in during which time it will brake - fine for car park stuff. Helps the battery last longer too...

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Can anyone tell me anything about the: KO PROPO RM-7 speed controler? A friend of mine is chucking a used one in to a load of stuff I'm getting from him. Anyone got any info on this?

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Afraid not. The only KO I've played with is the CX-III, but KOs in general weren't cheap when they were new but are of very nice build quality.

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