Matronics Email Lists :: View topic - Fuselage Conduit Support

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Fuselage Conduit Support
Goto page 1, 2 Next

Matronics Email Lists Forum Index -> RV10-List

View previous topic :: View next topic

Author Message

owl40188(at)yahoo.com
Guest

Posted: Tue Oct 24, 2006 7:37 am Post subject: Fuselage Conduit Support

I have ran a wire conduit under the passenger and baggage flooring.  This is the black stuff that Vans sells.  The conduit is only supported at the frame locations (total of 3) so there is no support between the baggage floor frames which is a relatively long length.

 I am wondering if this is acceptaple and if anyone else has done this.  My option is to drill out the baggage floor rivets and put in some more supports for the conduit.  This conduit will be carrying my battery cable.  Anyone know what the acceptable unsupported conduit length is?

  

 thanks

 

 

Niko 

40188

LarryRosen

Joined: 16 Jan 2006
Posts: 415
Location: Medford, NJ

Posted: Tue Oct 24, 2006 8:58 am Post subject: Fuselage Conduit Support

I cannot comment on how supporting the conduit, but



Instead of drilling out the floor board, now may be the time to add an 

access panel or 2 to the floor.  I used the same parts that are used for 

the wing stall warning access panel and installed them in the baggage 

floor so I have future access to the step mounts.  You can see photos 

here 

<http://lrosen.nerv10.com/Construct/Log/Fuselage/FloorAccessPanels/index.html>.

Michael Sausen used them in a different place in the baggage floor.  

Photos are here 

<http://www.mykitlog.com/users/display_log.php?user=msausen&project 2&category=613&log=15783&row=15>

I may add some additional access panels if and when they are needed.



Larry Rosen

#356



Nikolaos Napoli wrote:

 	  Quote: 	
		   I have ran a wire conduit under the passenger and baggage flooring.  

 This is the black stuff that Vans sells.  The conduit is only 

 supported at the frame locations (total of 3) so there is no support 

 between the baggage floor frames which is a relatively long length.

 I am wondering if this is acceptaple and if anyone else has done 

 this.  My option is to drill out the baggage floor rivets and put in 

 some more supports for the conduit.  This conduit will be carrying my 

 battery cable.  Anyone know what the acceptable unsupported conduit 

 length is?

  

 thanks

  



 Niko



 40188



 *

 *

_________________
Larry Rosen
#40356
N205EN (reserved)
<http>

jhasbrouck(at)woh.rr.com
Guest

Posted: Tue Oct 24, 2006 10:27 am Post subject: Fuselage Conduit Support

Niko,

      I've done the  same thing and supported the conduit under the baggage floor with adel  clamps.  #19 drill used midway along the baggage rib, #8 screw and nylok  nut at each station.  Works well. Also fabricated a bracket to support the  conduit as is exits the rear bulkhead into the tailcone.  Pics  included.



 John Hasbrouck

 #40264

100_0402_(Small).JPG

Description:

Filesize:

65.4 KB

Viewed:

338 Time(s)

100_0393_(Small).JPG

Description:

Filesize:

40.56 KB

Viewed:

368 Time(s)

jesse(at)itecusa.org
Guest

Posted: Tue Oct 24, 2006 11:10 am Post subject: Fuselage Conduit Support

This is what we did, but we used thicker-wall (stiffer) conduit with a smooth inside.  We made a bracket at the back of the baggage compartment to hold them with cushion clamps, tied them off to the step support, and used grommets in the holes going through the ribs and the rear seat floors.  There’s no such thing as too much conduit IMHO, especially with a 2AWG welding wire battery cable completely filling one.  

   

Do not archive.  

     

Jesse Saint  

I-TEC, Inc.  

jesse(at)itecusa.org (jesse(at)itecusa.org)  

www.itecusa.org  

W: 352-465-4545  

C: 352-427-0285  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Nikolaos Napoli

 Sent: Tuesday, October 24, 2006 11:36 AM

 To: Matronics

 Subject: Fuselage Conduit Support  

  

       

I have ran a wire conduit under the passenger and baggage flooring.  This is the black stuff that Vans sells.  The conduit is only supported at the frame locations (total of 3) so there is no support between the baggage floor frames which is a relatively long length.  

    

I am wondering if this is acceptaple and if anyone else has done this.  My option is to drill out the baggage floor rivets and put in some more supports for the conduit.  This conduit will be carrying my battery cable.  Anyone know what the acceptable unsupported conduit length is?  

    

   

    

thanks

    

  

Niko  

40188  

  

     	  Quote: 	
		  



href="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

DSC_5578.JPG

Description:

Filesize:

32.56 KB

Viewed:

325 Time(s)

jhasbrouck(at)woh.rr.com
Guest

Posted: Tue Oct 24, 2006 3:24 pm Post subject: Fuselage Conduit Support

---

100_0402_(Small).JPG

Description:

Filesize:

65.4 KB

Viewed:

281 Time(s)

100_0393_(Small).JPG

Description:

Filesize:

40.56 KB

Viewed:

268 Time(s)

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Tue Oct 24, 2006 5:35 pm Post subject: Fuselage Conduit Support

I put conduit under the baggage floor and supported it with adel clamps.  However, I did not like the Van's conduit. It is too flexible, making it very  difficult to route wire through. I bought 3/4" PEX pipe from the local plumbing  store. It is more flexible than PVC, yet much more rigid than the corrugated  black conduit. It is smooth on the inside and is just under 7/8" OD so it  was easy to enlarge the holes with a 7/8" unibit. I also put the conduit down  the full length of each wing, with a couple holes along the length to allow  wires to exit.

  

 PEX pipe is made for plumbing, so I did a non-scientific test to  compare it to Van's conduit. I used a heat gun to simulate an overheating  wire. Try taking a heat gun to the corrugated conduit: it  shrivels up like shrink wrap. By comparison the PEX is quite a bit more robust  when it comes to heat. 

  

 Photos attached.

  

 Jim McGrew

 Flying

  

 In a message dated 10/24/2006 7:26:28 P.M. Eastern Daylight Time,  jhasbrouck(at)woh.rr.com writes:

 [quote]    

   ---

129-2942_IMG.JPG

Description:

Filesize:

164.71 KB

Viewed:

303 Time(s)

136-3654_IMG.JPG

Description:

Filesize:

38.29 KB

Viewed:

285 Time(s)

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Tue Oct 24, 2006 5:43 pm Post subject: Fuselage Conduit Support

Niko – to the best of my review, your question has still gone unanswered.  The answer is, was and will remain - none.  

   

Now for the explanation.  Best Practices in AC 43.13 is to leave wire runs supported at 6” intervals.  The benefits are to reduce droop, reduce wire runs, reduce heat, enhance long term inspection.  Tim posted on his RV-10 University site a DAR PowerPoint on aging aircraft wiring.  It is blamed for the non-conspiracy cause of bringing down TWA flight 800 off the East Coast.  

   

Why is it used? Ease of wire pulling.  Ease of retro modification.  Why is the answer none.  Cause it has been found to mask the tell tale signs of an incorrect wire size and the carry amperage of the material selected.  Wire needs to keep cool.  With heat, resistance goes up.  Do airlines use conduit, yes in limited locations and usually light wall aluminum and for the reason of protecting wiring from chafing, adjacent heat sources such as exhaust stacks or de-ice lines.  Conduit, unless transparent, masks the ability to inspect progressively.  Do all certified GA aircraft avoid conduit, can’t answer that.  As little as practical I would guess.  It is often 3-4x ID of the conduit over  the OD on the final assembled wire bundle in it.  Again for heat dissipation.  Aluminum is great for radiating that heat build up away from selected hot spots.  Yes there are things that cause hotspots in wire runs.  

   

In Experimental construction, we too often use automotive, lower grade components, switches and fuses, conduit and non-aviation grade products.  The reasons given are often cost and convenience.  Nothing is wrong with those, if the evaluation takes in all the appropriate informational input. You get to answer what is appropriate. So you can answer your own question. Ask yourself why specs are different between DC and AC rated switches.  Can you functionally use the wiring tables to select the correct gage of wire for the wire run and current carry?  Do you know the effects of heat on the adjacent bundle?  Conduit is usually multiple run.  Do you know the difference in momentary and continuous use wiring?  

   

I will bet that not one single builder will change their decision to use it.  That is what makes building Experimentals so much fun.  Convenience!  

Want to post this question on the aero-electric list and watch the verbal joust begin?  

Ask Stein, his opinion.  Dan Checkoway did a pretty good post on his site for the failure of support tabs and the need to go in after one year and re-attach his wire runs.  

   

John   

40600  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Nikolaos Napoli

 Sent: Tuesday, October 24, 2006 8:36 AM

 To: Matronics

 Subject: Fuselage Conduit Support  

  

       

I have ran a wire conduit under the passenger and baggage flooring.  This is the black stuff that Vans sells.  The conduit is only supported at the frame locations (total of 3) so there is no support between the baggage floor frames which is a relatively long length.  

    

I am wondering if this is acceptaple and if anyone else has done this.  My option is to drill out the baggage floor rivets and put in some more supports for the conduit.  This conduit will be carrying my battery cable.  Anyone know what the acceptable unsupported conduit length is?  

    

   

    

thanks

    

  

Niko  

40188  

  

    [quote]



href="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List



[b]

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Tue Oct 24, 2006 6:17 pm Post subject: Fuselage Conduit Support

Jim, should we conclude that a heated wire bundle can be located quicker in Van’s black corrugated due to heat shrink.  And conversely, your PEX will mask the heat increase till the wires fuse?  You were right that it is about heat.  Should PEX be translucent? cause overheated wire is insulated with a product so that there is a marked and visible color change with excessive heat increase. Three distinct stages just like skin burns. Tim has some good shots.  I had forwarded him the same presentation in Living Color.  It is all about identification of an impending issue before reality sets in during flight.  Otherwise the discussion migrates to inflight backup systems / vacuum gages, fire annunciation, fire suppression and software to identify the safest and quick route to the ground with a safe departure from the aircraft.  

   

Always use the lightest gage, the shortest run, the highest quality to meet the task and to inspect for impending potential problems.  Wiring by its nature functions in a hostile environment.  

   

John  

Do not Archive  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of JSMcGrew(at)aol.com

 Sent: Tuesday, October 24, 2006 6:35 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Fuselage Conduit Support  

  

       

I put conduit under the baggage floor and supported it with adel clamps. However, I did not like the Van's conduit. It is too flexible, making it very difficult to route wire through. I bought 3/4" PEX pipe from the local plumbing store. It is more flexible than PVC, yet much more rigid than the corrugated black conduit. It is smooth on the inside and is just under 7/8" OD so it was easy to enlarge the holes with a 7/8" unibit. I also put the conduit down the full length of each wing, with a couple holes along the length to allow wires to exit.  

    

   

    

PEX pipe is made for plumbing, so I did a non-scientific test to compare it to Van's conduit. I used a heat gun to simulate an overheating wire. Try taking a heat gun to the corrugated conduit: it shrivels up like shrink wrap. By comparison the PEX is quite a bit more robust when it comes to heat.   

    

   

    

Photos attached.  

    

   

    

Jim McGrew  

    

Flying  

    

   

    

In a message dated 10/24/2006 7:26:28 P.M. Eastern Daylight Time, jhasbrouck(at)woh.rr.com writes:  

   	  Quote: 	
		      

   

    

----- Original Message -----     

From: John Hasbrouck (jhasbrouck(at)woh.rr.com)   

    

To: rv10-list(at)matronics.com (rv10-list(at)matronics.com)   

    

Sent: Tuesday, October 24, 2006 2:25 PM  

    

Subject: Re: Fuselage Conduit Support  

  

    

   

    

Niko,  

    

     I've done the same thing and supported the conduit under the baggage floor with adel clamps.  #19 drill used midway along the baggage rib, #8 screw and nylok nut at each station.  Works well. Also fabricated a bracket to support the conduit as is exits the rear bulkhead into the tailcone.  Pics included.  

    

John Hasbrouck  

    

#40264   

  	
  

    

   

  

      [quote][b]

bldgrv10450(at)comcast.ne
Guest

Posted: Tue Oct 24, 2006 7:20 pm Post subject: Fuselage Conduit Support

John

 Thanks for the post. I think of all the old  military aircraft I've seen over the years with wires bundled and tied to  structure. I had a rough-in electrical inspection on a building project today  and the inspector commented that the electrician did the right thing separating  the wires nailed down a wall line. He said that the circuit  breaker must be de-rated and / or the wire size increased if the wires are  excessively bundled (quoted some code stuff and lost me), also the maximum  length of conduit that a shielded wire can pass through is 24". 

 Thanks for the input, I'm going to do a little more  thinking about the wire runs.

 Paul Grimstad

RV-10 40450 fuselage

Portland,  OR 97219



 [quote]   ---

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Tue Oct 24, 2006 7:21 pm Post subject: Fuselage Conduit Support

All valid points, John. 

 

I would like to point out that one of the challenges that I found  as the 

RV-10 comes together is getting the wire runs 100% done  before I riveted those 

floor panels down permanently and before skinning  and installing the wings. 

Call it convenience if you will, but I ended up doing  90% of my wire runs 

through the conduit long after those areas were sealed  up. I certainly didn't make 

that decision lightly. I realize that I  deviated from a perfect world to 

make things come together.

 

Are you going to stay away from conduit altogether? How do you plan on  

inspecting the wires under the baggage floor area?

 

Jim

 

 

In a message dated 10/24/2006 10:19:42 P.M. Eastern Daylight Time,  

johnwcox(at)pacificnw.com writes:



 

Jim, should we  conclude that a heated wire bundle can be located quicker in 

Vanâ€™s black  corrugated due to heat shrink.  And conversely, your PEX will 

mask the  heat increase till the wires fuse?  You were right that it is about  

heat.  Should PEX be translucent? cause overheated wire is insulated with  a 

product so that there is a marked and visible color change with excessive  heat 

increase. Three distinct stages just like skin burns. Tim has some good  shots. 

 I had forwarded him the same presentation in Living Color.  It is all about 

identification of an impending issue before reality sets  in during flight.  

Otherwise the discussion migrates to inflight backup  systems / vacuum gages, 

fire annunciation, fire suppression and software to  identify the safest and 

quick route to the ground with a safe departure from  the aircraft. 

Always use the  lightest gage, the shortest run, the highest quality to meet 

the task and to  inspect for impending potential problems.  Wiring by its 

nature functions  in a hostile environment. 

John 

Do not  Archive 

 

  

____________________________________

 

From:  owner-rv10-list-server(at)matronics.com  

[mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of JSMcGrew(at)aol.com

Sent: Tuesday, October 24, 2006 6:35  PM

To:  rv10-list(at)matronics.com

Subject: Re: Fuselage Conduit  Support

 

 

I put  conduit under the baggage floor and supported it with adel clamps. 

However, I  did not like the Van's conduit. It is too flexible, making it very 

difficult  to route wire through. I bought 3/4" PEX pipe from the local plumbing 

store.  It is more flexible than PVC, yet much more rigid than the corrugated 

black  conduit. It is smooth on the inside and is just under 7/8" OD so it 

was  easy to enlarge the holes with a 7/8" unibit. I also put the conduit down 

the  full length of each wing, with a couple holes along the length to allow 

wires  to exit.

 



 

PEX pipe  is made for plumbing, so I did a non-scientific test to compare it 

to  Van's conduit. I used a heat gun to simulate an overheating  wire. Try 

taking a heat gun to the corrugated conduit: it  shrivels up like shrink wrap. By 

comparison the PEX is quite a bit more robust  when it comes to heat. 

 



 

Photos  attached.

 



 

Jim  McGrew

 

Flying

 



 

In a  message dated 10/24/2006 7:26:28 P.M. Eastern Daylight Time,  

jhasbrouck(at)woh.rr.com writes:



 



 

-----  Original Message -----  

 

From: _John  Hasbrouck_ (mailto:jhasbrouck(at)woh.rr.com)  

 

To: _rv10-list(at)matronics.com_ (mailto:rv10-list(at)matronics.com)   

 

Sent: Tuesday, October  24, 2006 2:25 PM

 

Subject: Re:  Fuselage Conduit Support



 



 

Niko,

 

I've done the same thing and supported the conduit under the baggage floor  

with adel clamps.  #19 drill used midway along the baggage rib, #8  screw and 

nylok nut at each station.  Works well. Also fabricated a  bracket to support 

the conduit as is exits the rear bulkhead into the  tailcone.  Pics included

Tim(at)MyRV10.com
Guest

Posted: Tue Oct 24, 2006 8:02 pm Post subject: Fuselage Conduit Support

I disagree with some of this.   First, conduit can also be additional

protection of the wire, from both being snagged by a moving control

service actuator, and from anything rubbing against the wire.  Of 

course, you also need to strive to ensure the conduit itself isn't

getting chaffed.  Next, flying a plane with wires in it, conduit or not,

will require diligent wiring and a leap of faith beyond that.

How many times do you realistically think you'll actually SEE the

wires, conduit or not, under your floors or in those sidewalls.

Yep, probably once a year on the walls, and maybe never again

after install on the floors.  So just run them right the first

time.  Also, what exactly is going to be going on inside a

nice bundled run of wires in conduit that will chafe them?

They're tefzel coated, and the wires would have to work pretty

hard to chafe eachother.  The heat factor is definitely a possible

problem, but the advice given below directly can contribute

to those problems.  Imagine using the "lightest gauge" wire possible

for all runs....you have choices....wires are sized according to

gauge that will give a specific temperature rise.  Stay within

the low rise specs and you shouldn't have much problem with

any of those bundles....going to the thinner wire with the higher

temp rise and you're getting closer to the limits.

Better advice, IMHO, is to absolutely properly size your

breakers and fuses, which are designed with the goal of

wire protection and limiting over-current situations in mind.

Agreed though that certain conduits are better than others

for temp ratings.  It's one reason I went with plenum rated

conduit under my cabin floors.  The removal from effects

of fumes and the proper selection of gauge or heavier

wire through the wings led me to have no worries in the

wings.  I ran out of 14 gauge at one point, so ran a 12.

There's no problem with that if you protect it with

the same smaller fuse.  Wire the whole plane with 10ga

if you wish...you're not sacrificing safety, just

gaining lots of un-useful weight.



Oh, and if the additional weight is going to be considered

a safety concern when running 18 ga instead of 20 ga wire,

there's a theory there too...

Take a peek in the mirror before going off the deep end

to save a pound in the plane, and consider where it's

probably will more likely save your life....skip the

cheeseburger.



There are positives and negatives to most every

choice you'll make....but try not to make mountains

out of molehills, or go throw out too many good

ideas because of minor concerns.  Wire chafing

and overheating are scary possibilities when things

go wrong...it's one of the reasons I have only one

battery-bus type wire in my plane, but that doesn't

mean conduit is always going to be a negative.



Tim Olson - RV-10 N104CD - Flying

do not archive

JSMcGrew(at)aol.com wrote:

[quote] All valid points, John. 

  

 I would like to point out that one of the challenges that I found as the 

 RV-10 comes together is getting the wire runs 100% done before I riveted 

 those floor panels down permanently and before skinning and installing 

 the wings. Call it convenience if you will, but I ended up doing 90% of 

 my wire runs through the conduit long after those areas were sealed 

 up. I certainly didn't make that decision lightly. I realize that I 

 deviated from a perfect world to make things come together.

  

 Are you going to stay away from conduit altogether? How do you plan on 

 inspecting the wires under the baggage floor area?

  

 Jim

  

  

 In a message dated 10/24/2006 10:19:42 P.M. Eastern Daylight Time, 

 johnwcox(at)pacificnw.com writes:

 

     Jim, should we conclude that a heated wire bundle can be located

     quicker in Vanâ€™s black corrugated due to heat shrink.  And

     conversely, your PEX will mask the heat increase till the wires

     fuse?  You were right that it is about heat.  Should PEX be

     translucent? cause overheated wire is insulated with a product so

     that there is a marked and visible color change with excessive heat

     increase. Three distinct stages just like skin burns. Tim has some

     good shots.  I had forwarded him the same presentation in Living

     Color.  It is all about identification of an impending issue before

     reality sets in during flight.  Otherwise the discussion migrates to

     inflight backup systems / vacuum gages, fire annunciation, fire

     suppression and software to identify the safest and quick route to

     the ground with a safe departure from the aircraft.

 

      

 

     Always use the lightest gage, the shortest run, the highest quality

     to meet the task and to inspect for impending potential problems. 

     Wiring by its nature functions in a hostile environment.

 

      

 

     John

 

     Do not Archive

 

      

 

     ------------------------------------------------------------------------

 

     *From:* owner-rv10-list-server(at)matronics.com

     [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of

     *JSMcGrew(at)aol.com

     *Sent:* Tuesday, October 24, 2006 6:35 PM

     *To:* rv10-list(at)matronics.com

     *Subject:* Re: Fuselage Conduit Support

 

      

 

     I put conduit under the baggage floor and supported it with adel

     clamps. However, I did not like the Van's conduit. It is too

     flexible, making it very difficult to route wire through. I bought

     3/4" PEX pipe from the local plumbing store. It is more flexible

     than PVC, yet much more rigid than the corrugated black conduit. It

     is smooth on the inside and is just under 7/8" OD so it was easy to

     enlarge the holes with a 7/8" unibit. I also put the conduit down

     the full length of each wing, with a couple holes along the length

     to allow wires to exit.

 

      

 

     PEX pipe is made for plumbing, so I did a non-scientific test to

     compare it to Van's conduit. I used a heat gun to simulate an

     overheating wire. Try taking a heat gun to the corrugated conduit:

     it shrivels up like shrink wrap. By comparison the PEX is quite a

     bit more robust when it comes to heat. 

 

      

 

     Photos attached.

 

      

 

     Jim McGrew

 

     Flying

 

      

 

     In a message dated 10/24/2006 7:26:28 P.M. Eastern Daylight Time,

     jhasbrouck(at)woh.rr.com writes:

 

          

 

         ---

dlm46007(at)cox.net
Guest

Posted: Tue Oct 24, 2006 8:04 pm Post subject: Fuselage Conduit Support

The aircraft mechanics handbook supplies a lot of  info regarding loads voltages ,wire sizes and conduits and bundles, you might  want to pick up a copy. 

 [quote]   ---

Jack.Phillips(at)cardinal
Guest

Posted: Wed Oct 25, 2006 6:29 am Post subject: Fuselage Conduit Support

What is the weight  comparison?

  

 Jack  Phillips

 #40610

  

  

 [quote]   

   --

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Wed Oct 25, 2006 6:38 am Post subject: Fuselage Conduit Support

Knowing the importance of inspecting wiring, that is a difficult task.  For one, I will not be permanent riveting floor panels.  I will use a 0.25” composite panel which is fastened into nut plates for ease of removal and inspection.  I also see value in access to the instrument panel area.  I will group bundles and separate their runs so each has the ability to shed heat independent of a specific run. There are specific circuits which tend to create the largest percentage of heat issues. Each aircraft is unique.  Tim did a great job posting his loads and analyzing this issue.  I will never intentionally load a wire circuit above 80% of its rated carry capacity.  I will be using welding wire for the battery terminals, starter leads and heavy intermittent amperage flows.  

   

The good news is we don’t run electrical wire through our fuel tanks intentionally. I will use only aviation rated circuit breakers.  No automotive (save a nickel) corner cutting.  I have already had an onboard fire on a 1978 Ford.  Nuf learned.  

   

A separate issue is grounding and twisted wire bundles to reduce avionic interference.  All of this is best covered elsewhere.  

   

John  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of JSMcGrew(at)aol.com

 Sent: Tuesday, October 24, 2006 8:21 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Fuselage Conduit Support  

  

       

All valid points, John.   

    

   

    

I would like to point out that one of the challenges that I found as the RV-10 comes together is getting the wire runs 100% done before I riveted those floor panels down permanently and before skinning and installing the wings. Call it convenience if you will, but I ended up doing 90% of my wire runs through the conduit long after those areas were sealed up. I certainly didn't make that decision lightly. I realize that I deviated from a perfect world to make things come together.  

    

   

    

Are you going to stay away from conduit altogether? How do you plan on inspecting the wires under the baggage floor area?  

    

   

    

Jim  

    

   

    

   

    

In a message dated 10/24/2006 10:19:42 P.M. Eastern Daylight Time, johnwcox(at)pacificnw.com writes:  

  [quote]    

Jim, should we conclude that a heated wire bundle can be located quicker in Van’s black corrugated due to heat shrink.  And conversely, your PEX will mask the heat increase till the wires fuse?  You were right that it is about heat.  Should PEX be translucent? cause overheated wire is insulated with a product so that there is a marked and visible color change with excessive heat increase. Three distinct stages just like skin burns. Tim has some good shots.  I had forwarded him the same presentation in Living Color.  It is all about identification of an impending issue before reality sets in during flight.  Otherwise the discussion migrates to inflight backup systems / vacuum gages, fire annunciation, fire suppression and software to identify the safest and quick route to the ground with a safe departure from the aircraft.  

   

Always use the lightest gage, the shortest run, the highest quality to meet the task and to inspect for impending potential problems.  Wiring by its nature functions in a hostile environment.  

   

John  

Do not Archive  

  [b]

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Wed Oct 25, 2006 9:12 am Post subject: Fuselage Conduit Support

Removable floor panels would be very nice, but quite a bit of work. I'm interested in seeing how that turns out. The rear seat and baggage area panels are structural (thus the 1000's of pop rivets holding them down), make sure you engineer your .025" composite panel and fasteners to handle the loads properly!

    

   Jim

   

 --

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Wed Oct 25, 2006 9:18 am Post subject: Fuselage Conduit Support

I did not even consider weight in my decision. PEX is certainly heavier. I have about 35' of it in my plane, assuming maybe 1 oz per foot thats 2 lbs. I didn't really worry about weight as I built N312JE, I built per the plans and ended up with 1570# empty (minus paint and wheel pants). Not too bad.

    

   Jim

    

  

 --

owl40188(at)yahoo.com
Guest

Posted: Thu Oct 26, 2006 6:25 am Post subject: Fuselage Conduit Support

Hi Jim,

  

 I actually think the access panels are a great idea and I thank everyone who responded to my initial quarry.  If I use the same panels used in the wing stall horn area its shouldn't be too much work as the pieces are allready made. As far as the floor being structural I don't believe that it is.  Its only supporting the weight of whatever baggage is placed in it.  The major loads are on the outer skins and the longerons.  Those rivets that are used on the baggage floor are very weak and typically are not considered to be structural.  Once the steel stem falls out of them all you are left with is a small hallow aluminum cyclinder.

  

 I am also thinking of removing the conduit from the baggage area now as it won't be needed there any more.  I am going with a recommendation that I got from a Pilot/ Mechanic friend that the fewer pieces of plastic in the plane the better as there are fewer things that can emit fumes and smoke in case of fire.  

  

 

Niko 

40188 

  



 ---

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Thu Oct 26, 2006 9:12 am Post subject: Fuselage Conduit Support

Yes, I think access panels like the one used for the stall detector would be good. That's a great idea. Removable floor panels seem like a bit more effort. Removable composite floor panels even more.

    

   I have no intent on getting into a structural design discussion, and I did not design the RV-10 so I can't say for sure: But those pop rivets are used the baggage area floor panels and attaching the canopy top to the fuselage. If those aren't providing (at least torsional structural) support through the middle part of the fuselage, I'm not certain what is holding the plane together.

    

    

    

  

 --

pitts_pilot(at)bellsouth.
Guest

Posted: Thu Oct 26, 2006 9:17 am Post subject: Fuselage Conduit Support

Nikolaos Napoli wrote:

  	  Quote: 	
		            Hi Jim,

  

 	
 snip   	  Quote: 	
		         I am also thinking of removing the conduit from the baggage area now as it won't be needed there any more.  I am going with a recommendation that I got from a Pilot/ Mechanic friend that the fewer pieces of plastic in the plane the better as there are fewer things that can emit fumes and smoke in case of fire.  

      

     

Niko     

40188   

 	
 Not bad advice on the surface, but if the fire has reached the baggage area .... your goose is already cooked.  Sorry for the bad pun.  There's already enough noxious (when it's burning) stuff in the cabin already so eliminating just a little 'something' isn't going to improve your chances of survival much.  But I'm an incurable optomist and I'll never suffer an inflight fire .... or a metorite strike or ..... well, just how many in flight fires (in small planes) have there been?  Well, I do know of a couple, and both of them were in aerobatic aircraft ..... abused far worse than our docile birds ever will.  Just a point of view.

 Linn

 do not archive

 

     [quote][b]

KiloPapa

Joined: 24 May 2006
Posts: 142
Location: Pearblossom, CA

Posted: Thu Oct 26, 2006 10:12 am Post subject: Fuselage Conduit Support

"Is the floor pan structural or not" is a question best  addressed by Van's.

  

 Kevin

40494

tail/empennage

  

 do not archive

 [quote]   ... As far as the floor being structural I    don't believe that it is.  Its only supporting the weight of whatever    baggage is placed in it.  The major loads are on the outer skins and the    longerons.  Those rivets that are used on the baggage floor are very weak    and typically are not considered to be structural.  Once the steel stem    falls out of them all you are left with is a small hallow aluminum    cyclinder.

    

[b]

_________________
Kevin
40494

do not archive

Display posts from previous:

	Matronics Email Lists Forum Index -> RV10-List	All times are GMT - 8 Hours Goto page 1, 2 Next
Page 1 of 2

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