MB metal 'thingy'

[Headcase]

Hi all.

I have a slight problem with my MB...

There is a small metal part attached to the outside of the chassis rail. There are three wires attached to it. It smokes like a sod when i plug the battery in. Anyone know what it is and if it's replaceable?

Cheers,

Rick

[mud4fun]

sounds like the speed controller resistor, you'll probably find that the ceramic is cracked. Cheap enough to get new ones but you'll be far better advised to spend £20 on a cheap electronic speed controller which replaces the awful 3 step mechanical plate speed control and the resistor. This will give you very fine smooth control of the car rather than the jerky standard controller.

[Headcase]

Sounds ideal!

Where can i get one?

What sort?

Help!

Thanks!

[fury_dice(2)]

quote:Originally posted by Headcase

Sounds ideal!

Where can i get one?

What sort?

Help!

Thanks!

---

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

The usual £20 ones are made by Mtroniks and are called the Eco27.

http://www.mtroniks.co.uk/carfr.htm

They are fine for the 'stock' Tamiya kit motor and are robust, waterproof and easy to set up. You will lose the switch that you currently have on your MB and will have to turn the car off by unplugging the drive battery. These things can be got from your LHS (TC-speak for Local Hobby Store/Shop) or mail order from loads of places.

You might want to check out your motor and/or wiring first though, as although the resistor gets hot when running, I'm not sure it should 'smoke like a sod' when you plug the battery in!

Hope this helps. David

PS. Your battery will last longer as well with an ESC, and longer still if you kit out your MB with ball bearings.

[mud4fun]

Your local hobby shop should stock them. Ask them for an electronic speed controller (ESC), if you are using your car for bashing about rather than racing you will probably want one that has reverse (Don't laugh some ESC's don't have reverse at all as some race meetings won't allow it!) Prices vary, you get what you pay for - also some ESC's are designed for use with very powerful motors or even twin motors. I doubt you need such things. The cheapest ESC I buy is a Futaba MC230CR which is an old model now and you should get them for about £20. At the top of the range I have Novak roosters/super roosters which cost in excess of £75+ but allow me to use high power motors. Once you have driven a car with an ESC you will not want to go back to a mechanical 3 step controller (MSC)!!!

[Headcase]

Thanks, David.

I've looked over the wiring and it all looks okay.

The first prob i had was the motor running without being switched on. I was told this can be caused by a low battery.

After charging the battery for a while, the metal thingy started smoking.

This was all after the car took a light/moderate impact to the front.

An esc sounds like a must, but any other tips or advice you can pass on will be very gratefully received.

Thank you,

Rick

[Headcase]

Resistor update:

Badly rusted and partially melted.

Prolly broken...

Hehehe

[fury_dice(2)]

Can't think of what else the problem could be at the moment (I should be working really [] ) - could be that the speed control servo (the device that actually moves the 'arm' of the speed controller) has gone out of alignment, and isn't sitting at 'neutral' when not switched on. If you've got the manual for the MB, then you can go through the radio set-up bit to get this right. If you haven't, then it's a good excuse to subscribe to TC and get access to the online manuals [8D]

As for advice, you're in the right place already!! Try searching the forums and generally having a dig around. Otherwise, these might help:

http://tamiyaeurocup.type3b.co.uk/cars/index.htm (the 'beginners' link at the top)

http://www.hobbypeople.net/rcsource/hsjack/introrcc.asp

HTH. David