hornet gear reduction

[Bigwheels_inc]

ok guys i know this is a weird one but my little daugher harmony wants a hornet and she's only 3

so i thought with all the info you guys have got about crawlers etc maybe you can help

i need to slow a hornet down my other daughter has a 380 in her hornet but i think thats too fast for the little one so i need to slow the speed down even more

i built the cars for my other daughters so id like to build little ones car rather than buying a qd

thinking reduction boxs etc ?????? [?]

any idea's

hmmmmmmmm twinset []

any help apreashated

cheers

pete

[theshopkeeper]

Why not put a 380 in with a 6 volt battery?

[Martin71RS(2)]

or an ESC with adjustable top speed...what I did for my son (robbe rokraft 100)

Martin

[Bigwheels_inc]

cool idea's guys noticed 6v battery doesnt make that much diffrence but the esc seems like an exellant idea does it damage the esc going slow all the time this hornet is going to be doing about 5 mph max so dont want to damage an exspensive esc

[Martin71RS(2)]

not to my knowledge... if you drive slow all the time your ESC keeps working too right??

best is to have an older style ESC with adjustment screws...the modern one button set up types won't work I think.

Martin

[aconsola(2)]

What about using a lunchbox motor plate and the long 9t pinion.

also you could try lower voltage, the 4-cell 4.8v batteries we use for 1/12 scale racing would keep the speed down and still provide enough power for the radio gear.

My daughter is 2.5 she drives for about 10 seconds and then hands over the controller to me so I can make her truck wheelie. every once in a while she will reach over and jam the steering full lock to make it crash.

your hornet is a pretty durable car, don't make it too slow, a girl's gotta have some fun [8D]

-Anthony

[Cul-Tech]

Put in a Lathe motor and an esc, you can then use the trim on the radio to slow down the esc and the lathe motor has very low current and speed to boot. A lathe motor costs about $20 and a reduction about $35 so that route is a little cheaper and you don't have to worry about space.

It would be a good idea to get an esc with thermal shutdown just to be safe.

When your done you can sell me the lathe motor for a good price[]

[DJTheo]

All very good alternatives, wouldn't recommend though using 4.8V if you don't use a separate Rx battery pack as the voltage regulator of the BEC circuit reduces it further more and the Rx and ESC may not work correctly.

Cheers

[WillyChang]

quote:Originally posted by DJTheo

All very good alternatives, wouldn't recommend though using 4.8V if you don't use a separate Rx battery pack as the voltage regulator of the BEC circuit reduces it further more and the Rx and ESC may not work correctly.

Cheers

---

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

A properly-designed BEC should take itself out of the circuit once

the input voltage reaches ~6V and just pump the full Vs to RX.

Novaks seem to do ok running off 4-cells.

[theshopkeeper]

The Acoms ones are ok in Mardaves running 4 cells so I think it shouldn't be an issue.

[DJTheo]

quote:Originally posted by WillyChang

quote:Originally posted by DJTheo

All very good alternatives, wouldn't recommend though using 4.8V if you don't use a separate Rx battery pack as the voltage regulator of the BEC circuit reduces it further more and the Rx and ESC may not work correctly.

Cheers

---

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

A properly-designed BEC should take itself out of the circuit once

the input voltage reaches ~6V and just pump the full Vs to RX.

Novaks seem to do ok running off 4-cells.

---

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

Unfortunately a voltage regulator can't just take himself out of the circuit, the is always a voltage drop, for example the National Semiconductors LM2940/LM2940C1A Low Dropout Regulator I use at a project at work has a voltage drop of 0.5V, but there exist some very low dropout ones with only 0.2-0.3V like http://www.analog.com/low_dropout_regulator.html (the 0.1V ones wouldn't work as they can take less then 1A)

Cheers

[terry.sc]

Whether the BEC works or the receiver bypasses it is irrelevant as Mardaves run on 4 cell packs and 1/12th races with 4 cell packs and I have yet to hear of anyone who has a problem with their radio gear, either high end receivers or cheap Acoms ones. As modern receivers assume there is a regulated 5v output from the ESC they are capable of running on 4.8v by design.

The only problem is whether the ESC is designed to work on 4 cells.

[kingeddie]

gearing down is ok (LUNCH BOX PINION) but you then give it more torque, quite slow but will climb anything, is the next door neighbour ok with your daughter running through/over their 1/1 car????????[]