HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 21, 2012, 01:10 PM
AndyKunz's Avatar
Illinois
Joined Sep 2001
23,061 Posts
sandy,

Please refer to your manuals. The answer is in there, both for the specifications of what the receiver will accept and the warranty policies, which vary by country.

Remember that the your servos should also be capable of accepting whatever you put on the voltage bus, so you will need to refer to their documentation as well.

I can only assume that you're either in Romania or the greater Washington, DC area based upon your posts, so I cannot give you specific information. Also, what I say here is totally useless - you need it in writing, and that writing is already in your possession.

I cannot answer questions outside my domain of expertise.

Neither should anybody else

Andy
AndyKunz is offline Find More Posts by AndyKunz
Site Sponsor
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 21, 2012, 02:04 PM
Registered User
seefest's Avatar
United States, MA, Bristol
Joined Sep 2009
1,561 Posts
Quote:
Originally Posted by mighty9 View Post
Who the heck flies any radio system @ 3.5 volts or below?Is that an electric fliers version of shaking every last drop out of the gas pump hose? I dont run my tank dry and i never run any battery that low.Thats most likely why i have never had a brown out period while flying . In 30 years of flying i have never had a battery just die while flying. I have had them shows signs of death on the charger .The saying "you cant fix stupid" comes to mind when reading all these auto crash conspiracies.
Dont pour hot coffee on your crotch either .
Some cheaper undersized BEC's can drop voltage to the 3.5V level or below........thats the main cause of brownouts. Even some BNF models come equipped with Underspec BEC's and brownouts were possible.
If the BEC is sized properly, theoretically there shouldn't be a problem.
seefest is offline Find More Posts by seefest
Reply With Quote
Old Mar 21, 2012, 02:42 PM
Registered User
richard hanson's Avatar
United States, UT, Salt Lake City
Joined Oct 2007
6,763 Posts
Quote:
Originally Posted by sandy11 View Post
Andy, are you ever going to answer my question about adding a 2S LiPo to boost servo bus voltage? It is a perfectly valid question first brought up by a Spektrum only customer here.

Does Spektrum warranty 2S (8.4V) powered Rxs?

The Spektrum users in this thread, including me, do that to help prevent blackouts as you know.

Another reason I ask is that Hitec states their view very clearly, "Almost all servos will burn-up if more than 6V is used for more than a short period of time." (Aurora 9 manual SPC section, page 21). But we would expect Hitec to say that since they are ghosting your need to over-volt the servo bus to help prevent Spektrum Rx blackouts.

What is Spektrum's official policy on warrantying 2S (8.4V) powered Rxs?
You are just being silly -to annoy others Right ?
If not -try reading specs for the various servos by various mfgrs .
You appear to be having fun -that's good but some readers are really new and they might actually believe some of these stories .
richard hanson is offline Find More Posts by richard hanson
Reply With Quote
Old Mar 21, 2012, 05:11 PM View Post
sandy11
A moderator felt this post violated the following rule: Trolling (Widespread). Show it to me anyway.
Old Mar 21, 2012, 05:18 PM View Post
sandy11
A moderator felt this post violated the following rule: Trolling (Obnoxious behavior). Show it to me anyway.
Old Mar 21, 2012, 05:23 PM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
23,625 Posts
Quote:
Originally Posted by sandy11 View Post
... They require maintaining 4.8V under load, which an ESC BEC cannot do with modern digital servos. ... .
My ESC/BEC has no problems supplying up to 7A to the servo bus with a main battery pack of up to 8S.

Instead of trying to get Andy to answer your stupid claims you should get informed before making such statements.

There is one fact that I am certain of, you have ruin this thread for me and many others.
freechip is online now Find More Posts by freechip
Reply With Quote
Old Mar 21, 2012, 06:00 PM
Registered User
richard hanson's Avatar
United States, UT, Salt Lake City
Joined Oct 2007
6,763 Posts
Quote:
Originally Posted by sandy11 View Post
Obviously Spektrum and other legacy Rx designs drawing voltage from the servo bus created the market for powerful BECs.

Andy declined to state Spektrums official RX voltage related warranty policy, and since voltage is never mentioned in their warranty language, we only can assume they endorse using up to 9.6V to help keep their receivers awake. They require maintaining 4.8V under load, which an ESC BEC cannot do with modern digital servos.

Hitec, as one of the largest and best servo houses as well as the A9 maker, officially states that most servos will be destroyed above 6V, not to mention other accessories.

That cements the safe voltage range when using legacy receiver designs powered by the servo bus at 4.8V to 6V.

That rules out LiPo/LiFe without voltage regulation, unless you want to risk frying a set of digital servos that could cost even more than the Spektrum receiver. You could spend more on high voltage servos but that certainly is not a cost competitive way to mitigate Hitec's less expensive Rxs that are not dependent on the servo bus.

That leaves three options

1) Add Pro BEC set to 5.9V at $40 and 1 ounce to every plane
2) Add LiPo/LiFe and voltage regulator at $50 and 3-4 ounces to every plane
3) Add 6V NiMH pack at $25 and 5.5 ounces to every plane

All add unnecessary weight and expense required by Spektrum's legacy Rx design. That's the point when comparing to Hitec's no cost, no risk Rx power solution.
You have truly reach a new plateau .
An entire post with no correct /information anywhere.
Jest having fun eh?
richard hanson is offline Find More Posts by richard hanson
Reply With Quote
Old Mar 21, 2012, 06:02 PM
Registered User
seefest's Avatar
United States, MA, Bristol
Joined Sep 2009
1,561 Posts
Quote:
Originally Posted by Bilymac View Post
Somebody on here reminds me of the 12 yo kid who was always the last to be picked for sports, so instead, he went home after school, sat at his computer and studied one subject. Then he gets on the forums and attempts to impart his knowledge on everybody else. Everybody has opinions......stop being so sarcastic with people, just because they like a different product. Go start a "A9 Lovers" thread, and stop trying to monopolize this one.
He doesn't need to start one. There's already one on this front page with 1.5 million views, by far the most viewed thread on this front forum page.
seefest is offline Find More Posts by seefest
Reply With Quote
Old Mar 22, 2012, 06:05 AM
Suspended Account
Joined Aug 2011
292 Posts
Quote:
Originally Posted by freechip View Post
My ESC/BEC has no problems supplying up to 7A to the servo bus with a main battery pack of up to 8S.

Instead of trying to get Andy to answer your stupid claims you should get informed before making such statements.
I don't think that's enough supply for a modern 5V setup according to Spektrum. They require 4.8V minimum bus voltage under max load. A digital servo draws up to 2 amps. One on each axis makes 6 amps plus the rest of the electronics takes you at least to your limit of 7. Even if the total wiring resistance is only half an ohm you are going to drop below 3.5V under load.

A 20 amp Pro BEC set to 6V is more comfortable for a Spektrum Rx pushing digital servos. Especially on a digital helicopter.

Quote:
There is one fact that I am certain of, you have ruin this thread for me and many others.
I think the thread title ruined it for you.
sandy11 is offline Find More Posts by sandy11
Reply With Quote  (Disabled)
Old Mar 22, 2012, 06:08 AM
Grow old disgracefully!
dickw's Avatar
Luton, UK
Joined May 2006
1,171 Posts
Some facts.
Anyone starting a flight should assume it could end in power failure at any point and fly accordingly.
The plane in the photo landed safely, but anyone using an ESC BEC for Rx /servo bus, either separately or combined would have crashed. A separate Rx battery or UBEC can fail as well - anything can.

The data log shows average Rx volts for every 0.05 secs recorded over a 5 minute flight using a separate "BEC" from a 360mAh 2s Lipo in a plane with 5 modern digital servos that flys at up to 150+mph. (Lipo recharged after every flight).
Max volts 5.272, min volts 5.229, = total variation of 0.043 volts.
(The BEC is home made and based on a 5A voltage regulator).
.
Opinion - I think the brownout problem may be exagerated now, and I have seen more power failures than brownouts

Dick
dickw is online now Find More Posts by dickw
Reply With Quote
Old Mar 22, 2012, 06:12 AM
Suspended Account
Joined Aug 2011
292 Posts
Andy, any chance of a software update for DX8 owners like me to catch up to the Aurora 9's seven point mix curves? Even five points would be mostly usable but if I were you I'd try to leap frog to nine or eleven point for mixes which need the resolution more than pitch and throttle IMHO. Will the DX18 at least use bring its ability to do seven point pitch/throttle curves into the mixing department, I hope?
sandy11 is offline Find More Posts by sandy11
Last edited by sandy11; Mar 22, 2012 at 06:19 AM.
Reply With Quote  (Disabled)
Old Mar 22, 2012, 06:15 AM
Suspended Account
Joined Aug 2011
292 Posts
Quote:
Originally Posted by dickw View Post
Some facts.
Anyone starting a flight should assume it could end in power failure at any point and fly accordingly.
The plane in the photo landed safely, but anyone using an ESC BEC for Rx /servo bus, either separately or combined would have crashed. A separate Rx battery or UBEC can fail as well - anything can.

The data log shows average Rx volts for every 0.05 secs recorded over a 5 minute flight using a separate "BEC" from a 360mAh 2s Lipo in a plane with 5 modern digital servos that flys at up to 150+mph. (Lipo recharged after every flight).
Max volts 5.272, min volts 5.229, = total variation of 0.043 volts.
(The BEC is home made and based on a 5A voltage regulator).
.
Opinion - I think the brownout problem may be exagerated now, and I have seen more power failures than brownouts

Dick
Hi Dick. Got any specs like for commercial BECs without a voltage regulated dedicated LiPo?
sandy11 is offline Find More Posts by sandy11
Reply With Quote  (Disabled)
Old Mar 22, 2012, 06:22 AM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
23,625 Posts
Quote:
Originally Posted by sandy11 View Post
I don't think that's enough supply for a modern 5V setup according to Spektrum. They require 4.8V minimum bus voltage under max load. .... .
You are assuming I was using a 5V bec when it's actualy programmed for 6.1 and have never recorded a drop below 5.9v

After many yrs of flying and never crashing due to power failure I think I got powering my system down right...
freechip is online now Find More Posts by freechip
Reply With Quote
Old Mar 22, 2012, 06:24 AM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
23,625 Posts
Quote:
Originally Posted by sandy11 View Post
Andy, any chance of a software update for DX8 owners like me to catch up to the Aurora 9's seven point mix curves? ...
If you know where to look and what to do with it once you find it, You can program it for 7 point curve. When I get home I will take a picture of a 7 point curve on a DX8 screen for you to think about.
freechip is online now Find More Posts by freechip
Reply With Quote
Old Mar 22, 2012, 06:28 AM
Suspended Account
Joined Aug 2011
292 Posts
Quote:
Originally Posted by freechip View Post
If you know where to look and what to do with it once you find it, You can program it for 7 point curve. When I get home I will take a picture of a 7 point curve on a DX8 screen for you to think about.
interesting, why did they hide it?
sandy11 is offline Find More Posts by sandy11
Reply With Quote  (Disabled)
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Spektrum DX8 or Hitec Aurora 9??? Irish Viper Radios 6 Oct 04, 2011 01:12 PM
Discussion Spektrum DX-8 or Hitec Aurora 9 new2heli Radios 15 Jun 12, 2011 01:07 PM
Found Have DX8, want Futaba 8FG, Hitec Aurora 9 or better Roswalt Aircraft - General - Radio Equipment (FS/W) 14 May 02, 2011 01:01 PM
Discussion Aurora 9 or Spektrum DX8 ? TeeJayBee Beginner Training Area (Heli-Electric) 11 Apr 06, 2011 09:47 PM
Discussion Spektrum DX8 vs. Hitec A9 Mikarro Radios 279 Nov 26, 2010 03:06 AM