Adding receiver battery to PK Zone T-28
11-23-2013, 12:08 PM
#26
Super Contributor
Join Date: Jul 2011
Location: Keller, TX
Posts: 5,019
I've experienced the complete loss of power problem as described by the OP and suspect Brown Out as Jet mentioned. Happened with my Spitfire.
I also suspect that the cheap linear BEC's that come with the cheap esc's may have been the culprit. The problem is that it's an intermittent thing. You bring everything back to the bench and suddenly servo's work, motor turns, etc. Scratch head. Can't make the problem repeat. Hard to find root cause. I then default to " pilot error" but swear out loud that it "just went dead ! "
With my more prized possessions (mainly balsa) and as a means to provide a warm and fuzzy feeling, I've been including a UBEC. Cheap insurance IMO.
-Hawk
I also suspect that the cheap linear BEC's that come with the cheap esc's may have been the culprit. The problem is that it's an intermittent thing. You bring everything back to the bench and suddenly servo's work, motor turns, etc. Scratch head. Can't make the problem repeat. Hard to find root cause. I then default to " pilot error" but swear out loud that it "just went dead ! "
With my more prized possessions (mainly balsa) and as a means to provide a warm and fuzzy feeling, I've been including a UBEC. Cheap insurance IMO.
-Hawk
11-23-2013, 12:16 PM
#27
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,910
Originally Posted by dahawk
I've experienced the complete loss of power problem as described by the OP and suspect Brown Out as Jet mentioned. Happened with my Spitfire.
I also suspect that the cheap linear BEC's that come with the cheap esc's may have been the culprit. The problem is that it's an intermittent thing. You bring everything back to the bench and suddenly servo's work, motor turns, etc. Scratch head. Can't make the problem repeat. Hard to find root cause. I then default to " pilot error" but swear out loud that it "just went dead ! "
With my more prized possessions (mainly balsa) and as a means to provide a warm and fuzzy feeling, I've been including a UBEC. Cheap insurance IMO.
-Hawk
I also suspect that the cheap linear BEC's that come with the cheap esc's may have been the culprit. The problem is that it's an intermittent thing. You bring everything back to the bench and suddenly servo's work, motor turns, etc. Scratch head. Can't make the problem repeat. Hard to find root cause. I then default to " pilot error" but swear out loud that it "just went dead ! "
With my more prized possessions (mainly balsa) and as a means to provide a warm and fuzzy feeling, I've been including a UBEC. Cheap insurance IMO.
-Hawk
https://www.youtube.com/watch?v=szK9QSOqiVs
So even with a BEC - not all is solved !!
Nigel
11-23-2013, 01:10 PM
#28
Super Contributor
Join Date: Jul 2011
Location: Keller, TX
Posts: 5,019
LOL- The beginning reminded me of a Tim Conway/Harvey Korman skit. Ker plop. Yeah, I get the diagnosis there. Was that a linear BEC attached to the ESC or a seperate UBEC ? Clearly, nothing is failure proof, right? I get frustrated on the intermittent type of failures. They can fool you into believing the wrong thing.
Off topic: I was saddened to learn about the roof collapse tragedy in Riga. Heartfelt prayers go out accross the pond.
-Hawk
Off topic: I was saddened to learn about the roof collapse tragedy in Riga. Heartfelt prayers go out accross the pond.
-Hawk
11-23-2013, 01:52 PM
#29
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,910
Originally Posted by dahawk
LOL- The beginning reminded me of a Tim Conway/Harvey Korman skit. Ker plop. Yeah, I get the diagnosis there. Was that a linear BEC attached to the ESC or a seperate UBEC ? Clearly, nothing is failure proof, right? I get frustrated on the intermittent type of failures. They can fool you into believing the wrong thing.
Off topic: I was saddened to learn about the roof collapse tragedy in Riga. Heartfelt prayers go out accross the pond.
-Hawk
Off topic: I was saddened to learn about the roof collapse tragedy in Riga. Heartfelt prayers go out accross the pond.
-Hawk
It's a Hypermarket that I use often when in Riga ... seeing the pictures now ... I don't know what to think. Just glad that I'm not at home - wife and I could have easily been there.
BEC - separate SBEC ...
Nigel
11-23-2013, 05:37 PM
#30
Super Contributor
Join Date: Apr 2008
Location: Wisconsin, USA
Posts: 8,952
Originally Posted by fhhuber
VERY CAREFULLY read your ESC's instructions about how it determines where to set LVC.
If your ESC sets the LVC by a percentage of initially detected, then you MUST use a meter to test and ensure the pack is FULL when you power up the ESC.
If your ESC sets the LVC by a percentage of initially detected, then you MUST use a meter to test and ensure the pack is FULL when you power up the ESC.
Yeah, that is a VERY good point. Several years ago, I screwed up on a giant scale model's maiden flight. After take off, and trying to get the trims adjusted properly, the model suddenly started acting strange.
The model was not high enough to determine what had happened, and it landed off field, doing a considerable amount of damage.
Didn't take long to figure out what happened, the motor had shut down. Because the Castle Creations ESC had been left in the original factory mode, with the LiPo battery configuration.
Running on A123's the ESC simply shut off power to the motor.
It took two weeks to repair the damage to the model. And, I made certain after that to make danged certain the ESC was properly programmed for flight. In my case, that was simply programming in a fixed LVC of 2.4 Volts per cell. That would be about 28 Volts on a 12S2P A123 battery pack.
Also, IMHO, it's poor practice to always fly to LVC, that could be hard on the batteries. And, if you have to go around, or if someone else is on the field, or is landing, or what ever, you could run out of power.
