[NSRCA-discussion] Lost Abbra
Bob Kane
getterflash at yahoo.com
Mon Aug 7 07:26:12 AKDT 2006
Ditto . . . . I have NiMH cells in 4 planes and 2
transmitters, I believe chemistry is more than
adequate. The oldest set is on it's 4th season with
hundreds of flights, still going strong.
--- Keith Black <tkeithb at comcast.net> wrote:
> I've been reading this thread and I serously doubt
> the NiMH batteries had anything to do with the
> crash. NiMH batteries aren't new on the market for
> goodness sakes and they've been working very very
> well on probably billions of flights. Sure we have
> digital servos, but in truth our loads aren't really
> very high and certinally not for and extended draw.
>
>
> I would think if low voltage had caused the loss of
> control then once the snap stopped, even though you
> had little time before hitting the ground, you still
> would have had enough time for the RX to come back
> to life. Remember, the battery did discharge 1540
> mah on the ground.
>
> As to the servo that was locked at full throw, if
> this had occurred in the air the plane would have
> been spiraling on it's way down and your other
> surfaces would have still worked. Therefore, you can
> rule out the jammed servo, that most certinally
> happened upon impact.
>
> As to the IMAC guys having low impedance problems I
> can buy this, but keep in mind these guys have two
> to three servos on each surface, their planes weigh
> 40 lbs, and they slam the controls like crazy doing
> blenders and such. The usage by pattern planes isn't
> even in the same galaxy.
>
> Most likely this was a simple case of lock-out due
> to reception. There could be some other factor, but
> I would hate to see anyone go back to NiCADs due to
> this incident.
>
> Keith Black
> ----- Original Message -----
> From: vicenterc at comcast.net
> To: NSRCA Mailing List ; NSRCA Mailing List
> Sent: Monday, August 07, 2006 7:44 AM
> Subject: Re: [NSRCA-discussion] Lost Abbra
>
>
> Thanks Chris,
>
> You are right. The event was so fast. Going down
> hill at 45 degrees didn't give me too much time.
>
> I went to NiMh two years ago. Looks like I am
> going to go back to NiCads. Several fellow pilots
> are telling me about the voltage drop problem of the
> NiMh. Probably, the battery was not the cause of
> the crash but I think I am going to feel more
> confident going back to NiCads. I went to NiMh
> because they are lighter for a given capacity. I
> agree that there has been a lot of comments in
> regard the low impedance. However, I really don't
> want to use NiMh after having this problem.
>
> I am planing to send the radio to JR for a
> complete check out.
>
> Vicente "Vince" Bortone
> -------------- Original message --------------
> From: "White, Chris" <chris at ssd.fsi.com>
>
> Hi Vince, very sorry to hear about your Abbra
> loss...not much time to recover or evaluate the
> problem considering where it happened. For what its
> worth, I've heard of airplane losses due to
> over-demand voltage during snaps . I also hear many
> of the giant scale guys are using "low impedance"
> nimh batteries when using nimh because of servo
> over-demand during certain maneuvers such as snaps.
> After hearing the low-impedance story I went to
> Hangtime Hobbies and am now flying their KAM 1800 6v
> low impedance packs. Their site is worth a visit
> just for the read.
>
>
>
> www.hangtimes.com/nobsbatteries.html
>
>
>
> I hope you find closure on the cause.
>
>
>
> Chris White
>
>
>
>
>
>
>
>
>
----------------------------------------------------------------------------
>
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org] On
> Behalf Of vicenterc at comcast.net
> Sent: Monday, August 07, 2006 5:49 AM
> To: NSRCA Mailing List; NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] Lost Abbra
>
>
>
> Ron,
>
>
>
> I checked all servos but throttle and one
> aileron servo. All are working on the bench fine.
> One of the aileron servos gears is locked in maximum
> travel position and I am assuming that was caused in
> the crash. However, I could be wrong.
>
>
>
> Thanks,
>
>
>
> Vicente "Vince" Bortone
>
>
>
> -------------- Original message --------------
>
> From: Ron Van Putte <vanputte at cox.net>
>
> On Aug 6, 2006, at 9:50 PM,
> vicenterc at comcast.net wrote:
>
>
>
>
>
> The battery was a little over a year old. I
> cycled the battery after the crash and got around
> 1540 mah. It was freshly charged and I was in the
> second fly. I use around 200 mah per fly so the
> battery was close to 2000 mah. I always charge at
> C/10 and never fast charged.
>
>
>
> I am discharging the battery now at 500 mah. I
> discharged the first time at 250 mah. I will keep
> increasing the discharge rate to check if I find
> something wrong.
>
>
>
> I am willing to bet that you will find a bad
> servo. Maybe Jim Oddino or one of the other radio
> wizards can explain, but a single servo can cause
> the whole system to crash.
>
>
>
> Ron
>
>
>
>
>
> -------------- Original message
> --------------
> From: "Scott Anderson" <scott at rcfoamy.com>
>
> How old are the NiMh batteries... People
> have found the have a steep drop off when going
> bad..
>
> scott
>
> ----- Original Message -----
>
> From: vicenterc at comcast.net
>
> To: NSRCA Mailing List ;
> nsrca-discussion at lists.nsrca.org
>
> Cc: Fred Huber
>
> Sent: Sunday, August 06, 2006 10:19 PM
>
> Subject: Re: [NSRCA-discussion] Lost Abbra
>
>
>
> Fred,
>
>
>
> Usually I called pilot (and/or mechanic)
> error until I find the cause of the crash. I haven't
> been in this position in a very long time. I tend to
> agree
=== message truncated ===>
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Bob Kane
getterflash at yahoo.com
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