Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Fwd: Re: IVOPROP Magnum installation instructions

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
jindoguy(at)gmail.com
Guest





PostPosted: Wed Apr 08, 2009 6:53 am    Post subject: Fwd: Re: IVOPROP Magnum installation instructions Reply with quote

Gosh Bob, you haven't even begun to bed in the prop blades, yet. The fun is just beginning.

Rick

On Tue, Apr 7, 2009 at 8:07 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:
[quote]--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

To: ivoprop(at)pacbell.net (ivoprop(at)pacbell.net)
Subject: IVOPROP Magnum installation instructions

By way of introduction, I'm a retired electrical engineer
with 40+ years in aviation and other venues. I write and
publish the AeroElectric Connection, a guide for the
crafting of modern electrical systems in owner built and
maintained aircraft. I support a website at

Http://aeroelectric.com

and moderate an aviation electrical systems discussion
group with over 1800 subscribers on Matronics. com

One of my readers tells me that instructions for
one of your products calls for installing a wire
harness in its as-supplied length. When he asked about
cutting it to length, he tells me that your service
folks told him that the wiring resistance was part of
a critical calculation for the sizing of circuit breakers
. . . or some such.

I'm mystified by his understanding of the assertion. I
offered to write to your directly and inquire as to the
elements of physics that control your wire sizing and
why he is advised to install so much extra wire that
is not useful to his project.

I hope you can clear this up for me. Thanks!



Quote:
Dear Robert, The elements of physics are not available.
The wire harness is used as a resistor. If shortened, too much current goes into the unit causing the carrier, gears, leadscrew, etc. to break. Once the spool reaches the stop, if the switch is continued
to be held the circuit breaker should pop within 5-7 seconds. It would be possible to shorten the wire
and put in its place a resistor that would cause the circuit
breaker to pop in the same amount of time. We do not encourage this because if there is a mistake,
parts will break and the factory sealed unit will need to be returned to our factory for repair. If the wire is too long it is best to just coil it up. Regards, Ron


� Ron,

� Hmmmm . . . I'm sorry to hear this. I would
� have wished that design goals and demonstrable
� robustness for this product were in closer
� agreement with commercial aviation practices.

� A motor driven gear train at risk for
� damage by hitting mechanical stops could
� not be qualified for use on a type certificated
� aircraft. If limit switches and/or mechanical
� torque limiters were not part of the basic
� design, then some form of electrical torque
� limiting is called for by tailoring the speed/
� torque curve of the motor -AND- limiting energy
� stored on the motor's armature when mechanical
� limits are reached.

� Is there a brake on the motor? What happens if the
� prop mechanism becomes disconnected from the motor?
� Will the mechanism back-drive? What pitch state does
� the prop go if the drive train becomes disconnected?
� It is stable in that state?

� What is the maximum expected operating current for
� the motor? What is it's expected stall current at
� 14.5V with the lead lengths as-supplied? What is
� the as-supplied wire size? What is the size and
� manufacturer's part number for the supplied breaker?




� � � Bob . . .

� � � ----------------------------------------)
� � � ( . . . �a long habit of not thinking � )
� � � ( a thing wrong, gives it a superficial )
� � � ( appearance of being right . . . � � � )
� � � ( � � � � � � � � � � � � � � � � � � � )
� � � ( � � � � � � � � �-Thomas Paine 1776- �)
� � � ----------------------------------------



===========
-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
http://forums.matronics.com
===========
le, List Admin.
="_blank">http://www.matronics.com/contribution
===========



[b]


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
 
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group