Today's Message Index:
----------------------
1. 07:03 AM - Re: Running Big Battery Wire Through Firewall (glen matejcek)
2. 07:55 AM - Re: Re: Running Big Battery Wire Through Firewall ()
3. 08:02 AM - Bob, Question on your WigWag flasher using a flasher relay (Brantel)
4. 09:21 AM - Flap motor draw for Rv-7A (Lincoln Keill)
5. 09:46 AM - Re: Flap motor draw for Rv-7A (wgill10@comcast.net)
6. 10:06 AM - Re: Flap motor draw for Rv-7A (thomas sargent)
7. 10:51 AM - Re: Flap motor draw for Rv-7A ()
8. 10:59 AM - Re: Flap motor draw for Rv-7A (Jef Vervoort)
9. 11:36 AM - Re: Flap motor draw for Rv-7A (Jef Vervoort)
10. 11:43 AM - Re: Calling Bob... (Jay Hyde)
11. 11:47 AM - Re: Calling Bob... (Robert L. Nuckolls, III)
12. 12:04 PM - Re: Flap motor draw for Rv-7A (Matt Prather)
13. 04:01 PM - Re: Flap motor draw for Rv-7A (Robert L. Nuckolls, III)
14. 07:00 PM - Re: Flap motor draw for Rv-7A (Robert L. Nuckolls, III)
15. 08:15 PM - Patent on "warm up" for wigwag of HID (XeVision)
Message 1
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| Subject: | RE: Running Big Battery Wire Through Firewall |
HI David-
To expand on this topic a bit, the preferred sealant is an intumescent fire
block, not RTV. You can get it in the aviation department of Lowe's et al.
I believe Bob has a tutorial on his website that covers all the detail.
All my sensor lines, including MP, pass thru these fittings.
glen matejcek
aerobubba@earthlink.ne
Message 2
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| Subject: | RE: Running Big Battery Wire Through Firewall |
Correct, also available at Ace and other fine Aero-motive department
stores. Cost is about $10/tube. After that you can install the remote
halon tubing and tips to put out the fire once it really gets going.
That will set ya back $500-$600 for the push type with a 5 lb tank.
http://www.acehardware.com/family/index.jsp?categoryId=2624911
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of glen
matejcek
Sent: Friday, March 12, 2010 9:58 AM
Subject: AeroElectric-List: RE: Running Big Battery Wire Through
Firewall
<aerobubba@earthlink.net>
HI David-
To expand on this topic a bit, the preferred sealant is an intumescent
fire
block, not RTV. You can get it in the aviation department of Lowe's et
al.
I believe Bob has a tutorial on his website that covers all the detail.
All my sensor lines, including MP, pass thru these fittings.
glen matejcek
aerobubba@earthlink.ne
Message 3
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| Subject: | Bob, Question on your WigWag flasher using a flasher |
relay
Bob,
On page 3.0 of your diagram on the single switch solution to a wig wag using the
flasher relay.....
You state that we can use a 15 amp breaker and 16awg wire for up to 2ea 100w lamps.
Is this correct or a typo? Since when not in wigwag mode the full combined current
will flow thru one 16awg wire, this seams to breaks some rules????
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290113#290113
Message 4
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| Subject: | Flap motor draw for Rv-7A |
Anyone know how many amps the flap motor draws on an RV-7A? -I don't see
it listed on the motor itself or on any of the documentation I've got and V
an's doesn't know offhand either. -I was going to use a 10A fuse and 14AW
G wire (total wire run of about 15 feet) which seems very conservative, but
I'd still like to know what the amperage draw is so I can calculate the to
tal "worst-case peak" amperage that my alternator & battery will need to pr
oduce. -Thanks.
Do not archive
Lincoln KeillRV-7A
Message 5
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| Subject: | Re: Flap motor draw for Rv-7A |
Lincoln,
I used 16AWG and a 3-amp fuse. That worked great for 2 years, but this wint
er=C2-the 3-amp fuse occasinally blew=C2-when really cold outside (-5F)
.=C2-I suspect the cold grease did not allow the motor to run its normal
speed.=C2-I upped the fuse to 7.5 amp during the winter and have since re
turned to the original 3-amp without further problems.
Bill
=C2-
----- Original Message -----
From: "Lincoln Keill" <airlincoln@sbcglobal.net>
Sent: Friday, March 12, 2010 11:17:34 AM GMT -06:00 US/Canada Central
Subject: AeroElectric-List: Flap motor draw for Rv-7A
Anyone know how many amps the flap motor draws on an RV-7A? =C2-I don't s
ee it listed on the motor itself or on any of the documentation I've got an
d Van's doesn't know offhand either. =C2-I was going to use a 10A fuse an
d 14AWG wire (total wire run of about 15 feet) which seems very conservativ
e, but I'd still like to know what the amperage draw is so I can calculate
the total "worst-case peak" amperage that my alternator & battery will need
to produce. =C2-Thanks.
Do not archive
Lincoln Keill
============
==
Message 6
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| Subject: | Re: Flap motor draw for Rv-7A |
I've been using a 5 amp fuse. I used fairly light wire - 20 or 22 I think -
because the use of the flap motor is very intermittent. It's just on for a
few seconds once or twice and then you don't use it again for an hour. You
can tolerate a wire which, under continuous use, would have a noticeable
temperature rise.
--
Tom Sargent
Message 7
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| Subject: | Flap motor draw for Rv-7A |
True as far as it goes=2C BUT the voltage drop on the small wire=2C dependi
ng on its length=2C may mean that the full design power of the motor is not
available. This may or may not be significant depending on=2C amongst othe
r things=2C your airspeed. It's also a little hard on the motor running it
at reduced voltage. Generally wires feeding motors should take voltage drop
into consideration so that the motor receives=2C as near as possible=2C fu
ll design voltage during operation however short or intermittant that opera
tion may be.
Bob McC
Subject: Re: AeroElectric-List: Flap motor draw for Rv-7A
From: sarg314@gmail.com
I've been using a 5 amp fuse. I used fairly light wire - 20 or 22 I think
- because the use of the flap motor is very intermittent. It's just on for
a few seconds once or twice and then you don't use it again for an hour. Y
ou can tolerate a wire which=2C under continuous use=2C would have a notice
able temperature rise.
--
Tom Sargent
Message 8
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| Subject: | Flap motor draw for Rv-7A |
I'm struggling with the same these days.
I found yesterday on www.ametektip.com <http://www.ametektip.com/>
\technical documents\Product Catalogs\Product Specification for the Pittman
motor 9234 series, from Vans, at 12 Volts: current @ continuous torque: 3,53
A and peak current 14,5.
Cold weather could weaken the battery.
Jef in Belgium;91031.
_____
Van: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] Namens
wgill10@comcast.net
Verzonden: vrijdag 12 maart 2010 18:45
Aan: aeroelectric-list@matronics.com
Onderwerp: Re: AeroElectric-List: Flap motor draw for Rv-7A
Lincoln,
I used 16AWG and a 3-amp fuse. That worked great for 2 years, but this
winter the 3-amp fuse occasinally blew when really cold outside (-5F). I
suspect the cold grease did not allow the motor to run its normal speed. I
upped the fuse to 7.5 amp during the winter and have since returned to the
original 3-amp without further problems.
Bill
----- Original Message -----
From: "Lincoln Keill" <airlincoln@sbcglobal.net>
Sent: Friday, March 12, 2010 11:17:34 AM GMT -06:00 US/Canada Central
Subject: AeroElectric-List: Flap motor draw for Rv-7A
Anyone know how many amps the flap motor draws on an RV-7A? I don't see it
listed on the motor itself or on any of the documentation I've got and Van's
doesn't know offhand either. I was going to use a 10A fuse and 14AWG wire
(total wire run of about 15 feet) which seems very conservative, but I'd
still like to know what the amperage draw is so I can calculate the total
"worst-case peak" amperage that my alternator & battery will need to
produce. Thanks.
Do not archive
Lincoln Keill
RV-7A
Message 9
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| Subject: | Flap motor draw for Rv-7A |
I'm struggling with the same these days.
I found yesterday on www.ametektip.com <http://www.ametektip.com/>
\technical documents\Product Catalogs\Product Specification for the Pittman
motor 9234 series, from Vans, at 12 Volts: current @ continuous torque: 3,53
A and peak current 14,5.
Cold weather could weaken the battery.
Jef in Belgium;91031.
_____
Van: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] Namens
wgill10@comcast.net
Verzonden: vrijdag 12 maart 2010 18:45
Aan: aeroelectric-list@matronics.com
Onderwerp: Re: AeroElectric-List: Flap motor draw for Rv-7A
Lincoln,
I used 16AWG and a 3-amp fuse. That worked great for 2 years, but this
winter the 3-amp fuse occasinally blew when really cold outside (-5F). I
suspect the cold grease did not allow the motor to run its normal speed. I
upped the fuse to 7.5 amp during the winter and have since returned to the
original 3-amp without further problems.
Bill
----- Original Message -----
From: "Lincoln Keill" <airlincoln@sbcglobal.net>
Sent: Friday, March 12, 2010 11:17:34 AM GMT -06:00 US/Canada Central
Subject: AeroElectric-List: Flap motor draw for Rv-7A
Anyone know how many amps the flap motor draws on an RV-7A? I don't see it
listed on the motor itself or on any of the documentation I've got and Van's
doesn't know offhand either. I was going to use a 10A fuse and 14AWG wire
(total wire run of about 15 feet) which seems very conservative, but I'd
still like to know what the amperage draw is so I can calculate the total
"worst-case peak" amperage that my alternator & battery will need to
produce. Thanks.
Do not archive
Lincoln Keill
RV-7A
Message 10
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Uh-oh, Bob Lee pointed out to me that there are more than one Bob on the
list. I am trying to get hold of Bob Nuckolls...
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jay Hyde
Sent: 11 March 2010 05:03 PM
Subject: AeroElectric-List: Calling Bob...
Hey there Bob,
I have been trying to send you mails to your address but do not seem to be
getting through- would you send me a mail to jay@horriblehyde.com to see if
I am getting the correct address?
Thanks
Jay
Message 11
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At 01:38 PM 3/12/2010, you wrote:
>
>Uh-oh, Bob Lee pointed out to me that there are more than one Bob on the
>list. I am trying to get hold of Bob Nuckolls...
No problem Jay. I'm trying to chase down some missing parts.
Will reply directly to you shortly.
Bob . . .
Message 12
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| Subject: | Flap motor draw for Rv-7A |
My hazy recollection is that running reduced voltage being hard on motors
depends on the type of motor.. I looked up what appears to be the
replacement motor and found a link here:
http://www.clickautomation.com/PDF/items/9234S004.PDF
I believe the peak current at 12V is found when stalled (RPM=0). Reducing
the Voltage should lower the current, reducing the temperature.
Again, my hazy recollection is that AC induction motors may not like
running with sagging voltage. Hopefully someone can remind me how this
works..
Matt-
>
> True as far as it goes, BUT the voltage drop on the small wire, depending
> on its length, may mean that the full design power of the motor is not
> available. This may or may not be significant depending on, amongst other
> things, your airspeed. It's also a little hard on the motor running it at
> reduced voltage. Generally wires feeding motors should take voltage drop
> into consideration so that the motor receives, as near as possible, full
> design voltage during operation however short or intermittant that
> operation may be.
>
>
> Bob McC
>
>
Message 13
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| Subject: | Flap motor draw for Rv-7A |
At 02:02 PM 3/12/2010, you wrote:
>
>My hazy recollection is that running reduced voltage being hard on motors
>depends on the type of motor.. I looked up what appears to be the
>replacement motor and found a link here:
>
>http://www.clickautomation.com/PDF/items/9234S004.PDF
>
>I believe the peak current at 12V is found when stalled (RPM=0). Reducing
>the Voltage should lower the current, reducing the temperature.
>
>Again, my hazy recollection is that AC induction motors may not like
>running with sagging voltage. Hopefully someone can remind me how this
>works..
A DC motor doesn't really have a "hard" voltage rating.
I.e., the nameplate only speaks to performance at the
nameplate voltage. In the case of the motor specs cited
above, you won't find all that good stuff on any nameplate.
I've purloined the speed/torque/amps curve from the
data sheet cited above and added a few more features
which can be seen here:
http://www.aeroelectric.com/Pictures/Curves/Speed-Torque-Current_Curve.jpg
The 12v speed/torque plot is shown in brown along with
the current torque curve shown in blue. Note that
the output of a DC motor is proportional to current
so ONE plot suffices for all conditions. The speed/torque
curve is bounded a the left end by applied voltage
divided by Ke (back EMF constant). With 12v applied and
zero load, we see about 6200 rpm. 9V applied yields
about 4600 rpm. 6V applied drops the no-load speed
to 1/2 the 12v value or 3100 rpm.
The right end of these curves is bounded by the internal
resistance of the motor. At zero rpm, the current that
flows in the motor is volts/ohms. 6V yields 1/2 the
locked-rotor current of 12V. Since output torque is
absolutely proportional to current, it holds further
that stall torque is proportional to applied voltage.
Now, suppose it takes 20 oz-in to move your flaps
a the top of the white arc on your IAS display.
Let's assume further that your alternator is working
and there's about 14 volts applied to the motor.
14V applied to this motor gives you a no-load speed
of about 7600 rpm and a stall torque of 48 oz in.
Let's say your 20 oz-in working load slows the motor down
to about 4300 rpm and the motor will draw just under
7.5 amps. Now, battery only the bus drops to 12v and
the speed comes down to about 3000 rpm. It will now
take about 1.5 times longer to extend the flaps. But
the current is still 7.5 amps. If your battery is
on its last legs and the applied voltage drops to
9V, 20 oz-in of load runs the motor at 1500 rpm.
Flap extension time is now 5 times longer than
at 14v. Guess what? The current is still 7.5A. As
the battery continues to die, by the time the
voltage drops to 6 volts, the motor speed goes
to zero, flaps stop moving and gee whiz, the current
is still 7.5 amps.
Obviously in this simplistic case, current required
to extend flaps is never constant over full stroke
of the mechanisms. When you have the performance
curves for the motor, you can deduce behavior
at what ever voltage and load you wish bounded only
by speed bounded by potential damage to motor, torque
(current) bounded by risks of smoking wires/brushes,
and ability to move at all bounded by applied voltage
divided by internal resistance which yields a stall
current (or torque at which speed drops to zero).
Now, when picking a wire size to drive the motor,
any resistance EXTERNAL to the motor is in series
with INTERNAL resistance which serves to reduced
stall current. Suppose your wiring resistance reduces
14v stall current from 48 amps down to 43 amps. Just
draw in a new line (yellow) to account for the motor's
'new' loop resistance. You can draw any number of
additional lines parallel to the 14v curve to predict
performance at the full range of applied voltages
as described above.
Want to know how your installation particulars
influence motor performance? Get the motor performance
curves at any voltage, get out your pencil and straight
edge, and plot it out.
Understand too that the efficiency/power curves for
EACH voltage/loop resistance combination will need
recalculation.
Bob . . .
Message 14
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| Subject: | Re: Flap motor draw for Rv-7A |
At 11:17 AM 3/12/2010, you wrote:
>Anyone know how many amps the flap motor draws on an RV-7A? I don't
>see it listed on the motor itself or on any of the documentation
>I've got and Van's doesn't know offhand either. I was going to use
>a 10A fuse and 14AWG wire (total wire run of about 15 feet) which
>seems very conservative, but I'd still like to know what the
>amperage draw is so I can calculate the total "worst-case peak"
>amperage that my alternator & battery will need to produce. Thanks.
As described in the posting of a few minutes ago,
wire size increases total loop resistance. This
has an easily predicted effect of reducing
stall current (translates to slow acceleration
of motor) and reduces speed of the motor.
At the same time, huge variability of voltage,
air loads and wiring resistance had have
MEASURABLE effects that may not even be
noticed by the pilot. How often do you check
flap travel times with a stop-watch?
Knowing the worst-case peak values are useful
only to the extent that you don't nuisance trip
your circuit protection. Using fuses to protect
a PM DC motor suggests some consideration for
weakening a fuse with repeated but infrequent
inrush values on the order of 30-50 amps . . . but
light guage wire goes a long way toward mitigating
that effect. Keeping voltage drop low improves on
motor performance but exacerbates inrush effects.
The 10A fuse and 14AWG wire is as good as any for
some reasons . . . upsizing to a 15A fuse is
good for other reasons. But one fellow talks
about pretty small wire and fuse . . . The motor
probably draws very low average current. Small
wire mitigates inrush. If this particular motor
seems sluggish during some portion of flap extension,
the pilot has no measured/considered reason to
attribute the effect to really high air loads,
small wire, undersized motor, or some combination
of those.
In the final analysis, it comes down to perceptions.
If it's been "doing the job" for some period of
time with no nuisance trips . . . well, it's
hard to argue with success! Doing what ever has
been installed in a few thousand RVs wouldn't
be a bad idea.
The point is, performance points for flap motors
in OBAM aircraft are all over the map. We could
spend a lot of time worrying about it . . . ultimately
fine tuning a decision that has no operational
benefits.
Bob . . .
Message 15
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| Subject: | Patent on "warm up" for wigwag of HID |
Our US patent was awarded Nov of 2009.
Vertical power has a license to use this patented technology in their units with
pulsing control capability.
Read this pdf news bulletin below.
http://www.xevision.com/pdf/Vertical...eVision_PR.pdf
We make 2 freestanding pulsing unit versions of our own, XePulse and XePulse II.
XePulse II is 1/3rd the size of our original XePulse (still available).
The original model (XePulse) has a terminal strip with 8 screw terminals. The new
XePulse II has a d-sub connector instead.
--------
LED still has a long way to go to compete with HID as a landing light. This is
true in terms of total lumens and reach (distance).
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=290170#290170
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