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PROLOGUE
Here you can find a story about a toy-snowmobile turning to a real RC-sled.
NOTE! I'm not sure about the technical vocabulary. Please let me know if there is something to correct. My email-address is in the
end of the page.
Everything started here:
Right after the moment I was born I was enormously interested about machines - and that hasn't changed since.
My another love has always been snow - and what would combine these two better than a snowmobile.
Unfortunately I'm living in biggest city of Finland, Helsinki, which locates very south of Finland, and there is
no sense to buy a real sled here. So when I saw
1/8 scale rc-sled in a Toys'r'us -shop, I knew that was for me.
The sled in the original outfit and almost the first time in snow.
Right from the beginning there were some disappointments:
- The speed was insignificant. Watch
this video (488 kt).
- Charging the batteries (600mAh) took four hours and then you could drive ten minutes.
- Steering was miserable. Full circle took even 5 metres.
- The drive shaft slipped really easily, especially if there was any snow inside the track.
- It was a typical toy: throttle was on/off -type, and steering everything-or-nothing -type - and everything wasn't much.
I drove about a month. Then I found some projects in the internet, where a toy was tuned a real rc-sled. That gave me the idea
to convert my sled too.
START
First I had to open the sled to see what there was inside.
The sled in the original outfit last time.
The "entrails".
I took out almost all the original electronics and technics.
You can see the track system and transmission behind the sled.
I bought a cheap, broken and ancient rc-car, from which I took the motor, servo and transmitter.
I was surprised how easily everything fitted inside the hood.
The new and the original together.
Bigger motor didn't require any large modification. Just a bigger hole for the engine and holes for screws.
The original speedcontroller was old fashioned mechanical and the transmitter needed four batteries.
Batterybox went smoothly under the engine.
Plastic made servorack. I had to increase the lenght of servo turning arm.
Original steering arm and tie rod. Suspension arms are blocking
the steering arms and prevent them to move enough to give better steering.
I heated these and bended a few degrees outwards.
Bending spot.
Bended and painted steering arm and new tie rod.
I changed the original front springs to Tamiya dampers.
Here you can see the original. There is only a spring, no damper.
I changed also new 30 000 mcd powerleds.
First test run made me smile really wide. The sled run much faster and the turning circle was only 0,5 metres.
With new 3000 mAh batteries I could drive twice as much as I used to.
I got also some sad news: Old speedcontroller heated too much and burned. The next day I bought a small Nosram ESC. That gave me
the chance to throw away the old batterybox.
I replaced everything on the left by this one small ESC. Modern times, here we come!
Sled with the new ESC.
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