how to make a rc toy car and rc helicopter?

make a rc toy sounds so Trouble,i think.if you have some interst ,you may visit http://www.chinajiaho.com where list all kinds of rc toys!
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It's not impossible but it would be very time consuming and a ton of parts, that is if you are talking about building one from scratch, ie, your own chassis, mounts, etc. To get you started though, you would need to decide if you are going to make it electric or nitro powered. You would need a receiver and transmitter, an electronic speed controller and electric motor (electric RC), or a nitro motor and throttle servo. Steering servo, rear differential (and front if you are making it 4×4). Then you would have to make the front end, A Arms, wheel hubs and axles, steering and throttle linkage, etc. It would be difficult to fabricate these pieces yourself. You could always use other RC parts and piece one together. A heli would be even worse, I won't even get into that. There are actual RC kits you can buy. They come complete in pieces and you get to build it that way. It's a good way to get into the hobby because you are seeing and building the RC first hand and will know how to fix it when it breaks. Tamiya, HPI, Kyosho, Associated all make RC kits. Check them out, that might be the easier route to go.
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15+ years in the RC hobby