RC10Talk - The Net's Largest Vintage R/C Community

Hello, on my Rockies 4wd Kyosho I put new Radio gear which offers the possibility to limit top speed. Nice but that is still too fast for my kids...
What options would I have ?

-motor change ? The genuine period LeMans 240ST could be replaced by slower one ? Can you please advise me on which one ?
-I read that some are cracking their 7,2v NiMh batteries to rebuild them less powerful: is there a tutorial to help down not that mod ?

Any other advice would be welcomed ! Thx in advance !

TO change the battery, Take out a cel. resolder to a 5 cell 6 volt. depending on radio, turn down the endpoints. Or another cheap way. If a pistol radio, tape on handle behind the trigger so it cant be pulled all the way down to get to full throttle.

Taking out a cell might not work with modern ESCs. If they don't detect enough voltage, they won't work at all. Adjusting the throttle endpoints is a good idea. If it's a Castle ESC (and surely others are similar), use the Castle Link (or other similar) software to change the output. I had to do that with a 2S 1/12-scale pan car because with 2 cell LiPo, it was just way too fast, all it would do is spin out uncontrollably. I think I had to turn it down to 40% or something just to make it controllable.

If they are small kids, a good option is a crawler motor. 35 or 55 turn. Very torquey but not many rpm. I put one in a lunchbox for my boys when they were 4 yrs old and worked pretty well.

Thank you for your answers. They actually are very small kids... 6 and 3.5 yo ! From what you wrote, I would try the otion: motor change. Why ? Cause that would make the trick of slowing down and... The LeMans 240ST (22T by the way) were not made to run for long periods and stop/accelerate/stop like kids drive them... so changing the motors would address more than one issue... what you think of this statement, am I correct in the reasonning ?

I don't think the extra torque of a 35T or 55T would be such a hit if managed by an ESC, the acceleration and braking power is managed safely, right ? Can I damage my trans' with that kind of motors ?

Ok so I bought 35T motor, of the below brand. "Yeah Racing Hackmoto 35T", they are cheap and available where I am...

http://www.yeahracing.com/catalog/mt0014-hackmoto-brushed-motor-p-3560.html

MT016 (55T) is R.P.M:7550
MT015 (45T) is R.P.M: 8850
MT014 (35T) is R.P.M:13200

Am I right to consider that 13200 would cut by more than half the today's speed (25000 RPM down to 13200 RPM) ?

Many thanks, again, for sharing your valuable experience !

yes, you will be fine. they are torquey, so the only potential issue is if they run head on into something and keep it floored, but any damage would occur with any motor. it's best to teach them right out of the gate to release the controls if the car is stuck until dad can fix it.

In addition of that good advise, the modern ESC features something I even didn't knowof my old days : now you can teach them to fully reverse back the throttle in case of emergency ! In the past that was bad cause reversing the gearing at full speed. But nowadays, since you setup ESC to backbreak, the gearing will not go reverse before speed is down to zero. And only on a second trigger reverse push, the car will get backwards. That adds a lot of peace of mind ! So you are right, lesson is to practice breaking first.

Funny enough it seems like it is not a common thing to seek advise to reduce speed of a buggy ! Everybody is looking for MORE speed, always MORE speed... Ok... How to I get my racing buggy to CRAWL instead

***update***

The order of two 35T motors went extremly fast, got them by post within 12h ! So yesterday after a bit of bed-in, I replaced one of the Le Mans of my kid with this little 35T and ????? Well, still way too fast ! I don't have the feeling it goes much slower than the Le Mans 240ST which is a 22T.

So back to the internet and ordered 55T this time !

Do you think I will get what I intend or if I really want a SLOW buggy, I will have to work on the gearing as well ? The pinion itself is a 14 teeth thing... I have no idea how to replace that in a Rocky.

Pictures of the work, because we all love pictures !
Thank you !

Hello, got the 55T mounted. Finally, works fine as wished ! In mode "fast" (handset switch training mode) you get 11 Kmh and if mode "slow" is selected it is 6-7 Kmh. That's perfect for my sons !

Thx all to nice advices

I just built an original RC10 for a twelve year olds birthday (http://www.rc10talk.com/viewtopic.php?f=35&t=39992) and went through the same problem.....came to the conclusion that a twelve year old is old enough to understand and learn throttle control, trust me, he learned throttle control pretty quick....

Hello, you are certainly right. But my sons are 6 yo and 4 yo ! So that's a different level. Having said that, I must say that I am impressed like my 6yo son, after 2h playing with its Rocky 55T (thanks to new NiMh batteries 4700 which last for ever compared to the old days... and with a 55T it lasts even more) was able to move in "full" mode (means 55T motor but without the top speed limitation offered by the radio) and he does a great job. He controls speed and steering very well. On the steering I told him to avoid "full right" or "full left" but to try to be more refined and proportional: so he did and now, gets a good feeling about steering. I am very surprised it went so easy ! Very few crashes, almost none. After so much playing the car was not damaged at all. The 55T "full speed" gets up to 9-10 kmh and that's perfect speed for that age.
The 4yo boy, well, it is a different story. He just cannot focus on one thing so he is not ready and I have to play with him.

The 55T motor is even not warm after playing non stop with it for 20 minutes ! LeMans was impossible to touch, burning hot !

I am very happy. And so they are.

very cool. glad to hear!