dacaur
Posts: 2624
Score: 126 Joined: 4/18/2005 Last Login: 8/17/2012 From: midvale,
UT, USA Status: offline
|
Guys, the ESC's you are linking are for airplanes, not cars. three problems you will run into, #1, they dont have reverse, because planes dont need it. so it will be forward only, assuming you can overcome problem #2. #2, "Neutral" on a car transmitter is actualy 50% throttle. A car ESC is designed to see that as neutral, but an air ESC sees it as 50% throttle. In order to get a brushless airplane esc to arm, it has to se 0% throttle, which is full reverse on a car transmitter. so you would need to hold full reverse on the transmitter to get it to arm, and then when you let go of the trigger, the truck will start moving forward at 50% speed... not real useful. And #3, air ESC's dont have heatsinks, so they will likley overheat in an RC car with no airflow. Even though they are rated higher than the truck needs, a crawlers amp draw spikes whenever the wheels get stuck, and air ESC isnt made to handle spikes like that, because an airplane propeller never gets stuck. THat's why car ESC's have heatsinks . Also, you can NOT run two brushless motors off one ESC. If the motors are hand wound and perfectly matched it sometimes works in an airplane, but i have never seen it work in an application like this, and I can tell you one chinese ESC is NOT going to run two chinese motors. You need an ESC for each motor if you go brushless. The Ubec is not necessary regardless of the ESC you use. those are made for applications that have a high servo current draw, like an airplane with 4+ servos. You wont need it in this. Using a speed controller and a motor on the steering will not work. It works on toy RC's because the circuit of the toy is made to control it, but real RC stuff doesn't work that way (because its a retarded way to do it) You will need a real servo, but it will cost you less than an ESC and motor anyway, so its better. If you want to buy from hobbyking, and want to go brushless, here is what you need: The radio linked above will work fine. The motors linked above should work fine, but a lower KV would be better for a rock crawler, especially if you are using higher voltage. (the motors linked are 3500kv) Of course, thats assuming the screw pattern in the truck is a standard pattern, I havent taken mine apart so I couldn't say. ESC X2 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14630 Steering servo, an mini or micro servo will do, but you will have to figure out a way to mount it... shouldn't be too tough really. You could also pick up a brushed car ESC and use it to run both of the stock motors. ebay is a great place to look, you should be able to pick one up for under $30. Good luck! One more thing... the main limiting factor on the torque this thing makes are the AA's, they cant produce the amps the motors ask for, especially when its going uphill and hits a rock... so dont think you can upgrade this without also upgrading the battery. I would recommend getting a 2 cell lipo battery, in the 800mah range (for size) Lipos can be dangerous and HAVE to have a charger made to charge them, or WILL catch fire, so read up on them, use the right charger and charge them properly and they are safe,... alternatively, you can just use a 6 cell battery pack made for a 1/18 size RC car... Just upgrading the battery on this thing to a 2 cell lipo makes it a whole new truck... the AA's really just suck...
_____________________________
1/16 e-revo vxl, Mini LST2, Blade 120SR heli, Blade MSR heli, Blade MBCX heli, Slowstick, Minimag, DX7, DX3S
Hide Signatures
|