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Old 03-28-2012, 11:06 AM   #1
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Default New to nitro. Question about failsafes.

I'm going to build an RC8.2 soon and was wondering if I need to get some kind of failsafe module to prevent runaways.

I haven't seen any discussion of it while looking around the 1/8 scale nitro discussions.

Would a Futaba 4PL and/or Hitec 7955 servos have some kind of built in function so I could program the servos to return to center position in the event of signal loss?
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Old 03-28-2012, 11:26 AM   #2
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It is the receivers these days that do the failsafe positioning.
On most radios, when you bind them you also set the failsafe position of the servos, which for Nitro I would suggest should include brake, rather than just neutral.

Spektrum, for example, you simply hold the position you want on your transmitter when you bind, and that is remembered as the failsafe position. You can test it by simply turning off the transmitter, and you should see your servos go to failsafe positioning.
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Old 03-29-2012, 12:57 AM   #3
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Thanks for the info.
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Old 03-29-2012, 01:52 AM   #4
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Quote:
Originally Posted by Square Wheels View Post
I'm going to build an RC8.2 soon and was wondering if I need to get some kind of failsafe module to prevent runaways.

I haven't seen any discussion of it while looking around the 1/8 scale nitro discussions.

Would a Futaba 4PL and/or Hitec 7955 servos have some kind of built in function so I could program the servos to return to center position in the event of signal loss?
Most runaways Ive seen are caused by battery failure. At which point a failsafe is useless. Attach a rubber band to throttle ball and HSN to pull it closed in case of battery fail.
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Old 03-30-2012, 01:42 AM   #5
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Thanks for the added perspective. I'll find something that will close the throttle if the battery fails.

I've seen a couple of cars take off out of control at my local track and I don't want that to happen with my car.
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Old 03-31-2012, 12:54 AM   #6
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Most runaways Ive seen are caused by battery failure. At which point a failsafe is useless. Attach a rubber band to throttle ball and HSN to pull it closed in case of battery fail.
+1, Ive had a runaway with a flat reciever battery. Was recomended a rubber band as a precoution.

A little tip if you get a runaway nitro, once you get your hands on it push all 4 wheel hard to the ground, this will restrict the motor from reving its nuts off then with you sole of your show firmly cover the exaust stinger till the motor dies, dont try to stick anything into the flywheel, motor spinning at 35,000+rpm will chew up most things with ease. When it first happens to you it can be a bit scary trying to figure how to shut it down.
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Old 03-31-2012, 11:01 AM   #7
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Thanks for the tip re: holding the wheels firmly to the ground to stop over-revving...nice to know. I recently marshalled at a track with nitro and electric (alternating) and I know nothing about nitro vehicles, but nice to know that tip in case it's ever needed.
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Old 03-31-2012, 02:45 PM   #8
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+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
Has any nitro guys try one of these yet?http://www.killerrc.com/products/nitro_killswitch.php

I have gas version on my boat and will never start my motor with out it.
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