Avoid a Crash the Fail Safe Way
Wednesday May 10, 2006
In response to my article on Choosing Your RC Car Frequency, a reader, Marc, wrote to me suggesting that I should also mention fail safe units as a way to avoid the problems associated with frequency interference. While my article primarily focuses on radio frequency with toy-grade cars, fail safe units are a highly desirable accessory for hobby-grade RCs. Used in gasoline or nitro RCs as a way to make sure you don't suffer the consequences of an out-of-control RC doing 30+ mph, a fail safe unit is connected between the receiver and throttle servo of the RC. It monitors the connection between the transmitter and receiver for disruption and/or interference -- as well as total battery pack strength. Failures such as lost signal, frequency interference, or low battery will automatically engage the vehicle braking system, stopping or slowing down the RC.
These little lifesavers can provide peace of mind and are a fairly cheap way to avoid costly repairs that result from runaways and crashes due to signal problems. In addition to the fail safe accessory that can be added to an RC, there are some ready-to-run vehicles such as the Ofna 1:8 scale MBX Buggy that come with a fail safe device installed.
Compare prices on a few different RC fail safe devices:
Comments
Electric Fail safe is good but not a 100 solution, nothing is, but something non electrical to act as a fail safe for the fail safe, or simply, the fail safe, would beso much better:
with ANY elec. F.S. if your receiver battery dies, your RC will go out of control even if you “had” 10 elec. F.S. so using this as an example, wouldnt it be better to get a properly made spring on the carburetor and if required, a stronger servo, to handle the extra presure created by the spring to provide possible the best solution for the “wild beast” issue?
Agreed, If your batteries in the control is low, fail safe works great.
If the batteries are low in the car, say less than 4.2V, then the servo will have slow response and is not always 100%. USE FAIL SAFE AND RETURN SPRING.
Like Shane says use a spring or something else. If you have a slide carb like the ones on force engines then use a hair tie around the HS needle and the throttle link or similar.
*use hair ties or springs and test they are strong enough to return to breaking or neutral position, but not too strong to use too much power from your servo or breaking it.
Test (engine off)full throttle the servo then turn off the transmitter, the hair tie should pull back to a neutral position.
***Do not use runner bands, the are not as consistent and the oil and fuel will melt it (polar and polar).
Before each use check the F.S and hair tie, and obviously your batteries.
EDIT: ^braking, not breaking, hehe breaking position.
EDIT: non polar and non polar.
I really should think before I type.