Jump to content

External rudder conduit.


mfryer

Recommended Posts

I am about to skin the outside of the fuselage. However it has been suggested that I might install the rudder cable conduit through the side foam. My primary reason for this is to avoid having to drill a hole through the landing gear brackets.

 

However after discussing this with my brother I am having second thoughts. Mainly what I am about to do is a departure from the plans and it involves a control system, so I am a little shy about it.

 

Also I saw this clip on

, about a third of the way through it shows some nifty rear seat rudder peddles. I do not see how this could be accomplished if I ran the conduit through the side foam.

 

I bought a long 3/16" bit and drilled from the inside just behind the rear landing gear pad forward as seen here. More photos can be seen at http://flyingbackward.blogspot.com/

Flying Backward

 

Posted Image

 

 

Any thoughts or suggestions????

Link to comment
Share on other sites

Posted Image

Martin, check the W.L. height of your 15-ply bid pads and the top of your aft main gear attach brackets, if either or both are above WL 12.35, you may have a Posted Image moment coming when you try to install the engine mount extrusions. If you’re using the Open-EZ templates, check A5, just aft of the aft-MGA bracket (near the top), there is a small penciled-in CP note addressing this. If you need to make any adjustments, pre-spar installation is the time to do it.

Hat

Airspeed is Life -

:cool: - Having lots of it

is Better!

Link to comment
Share on other sites

Ahh, don't be sad, be happy :rolleyes: I'm sure you're in very good company with this one: From what I could gleam from the pictures posted on your blog: First, I think the work looks good, really good; Second, I think both the 15-ply pads and the bracket are relatively EZ to fix at this stage (cut-sand-go out for lunch). While you are in the midst of that little task, all you have to do to make yourself feel better, is think about having to do the same thing, only after :irked: the spar is floxxed in!

 

A few more things come to mind here: IF your aft MLG brackets are fabricated to size per-plans, and the attach bolt hole locations are drilled per-plans, but, the AN6-80As were drilled at the PC call out of "up 0.04" as called for in CP??, and assemblies currently check to be installed up past W.L. 12.35, that could mean: The brackets are installed higher on the fus than plan spec'd, which means the lower attach bolts punch through the lower longeron doubler High and have less spruce-meat over them; the AN6-80A's are currently higher on the fus than they should be, which could mean (if all else to follow is built per plan) your ramp-AOA will end up higher, and your prop-arch will swing closer to the ground.

 

This is what I'd consider doing in lieu of ripping it all out and starting over: - If the AN6-80A ARE currently at the W.L. level they should be considering the PC 0.04" change to the plan, and the lower bolts ARE drilled through High on the lower longeron. Carefully channel out the 15-ply bid pad under the bracket enough to allow the engine mount extrusion placement (WL 12.35 or lower) leaving the top of bracket unaltered (except as needed to allow extrusion bolts) to overhang the extrusion. Maybe also consider flox-packing the overhangs after the extrusions are installed. As far as the lower bracket attach bolts: If they are drilled "up" from longeron center and are lean of spruce, (cause of structural concern?) channel out the eurethane equal to the size of an additional spruce incert to work as a new doubler (trippler?) flox it it in, use gravity and leverage as your clamp.

- If the AN6-80As ARENOT currently at the W.L. they should be considering the PC 0.04" change to plan: All of the above; consult our structural and or experienced builder/fliers gurus, make adjustments and any buildups needed when you fab to install your main gear bow.

 

In any case, don't let this stall your progress, press on, consider dealing with it when you have lag time. Just as long as its before the spar install. Hope this helps. Keep up the good work.

Hat

Airspeed is Life -

:cool: - Having lots of it

is Better!

Link to comment
Share on other sites

Correction: Any ref to 0.04" mentioned above should read 0.4" (4/10ths). But you guys are ready knew that! :D Sorry for the typos.

Hat

 

Ref: Long-EZ plans change #45 CP27. http://www.cozybuilders.org/ref_info/Canard_Pusher/LongEZ_Plans_ChangesUpdate.htm

Thanks for the input. It will take me a while to wrap my head around all of that.

 

Also thanks for the complement, however folks out there should be aware that if there is the illusion that my work is somehow great or good, it is only due to the fact that my garage floor has a 1970s pattern that causes the brain to adjust its sense of taste and could alter ones perception of the quality of other objects in the vicinity.

Link to comment
Share on other sites

. . .

it has been suggested that I might install the rudder cable conduit through the side foam. My primary reason for this is to avoid having to drill a hole through the landing gear brackets.

 

However after discussing this with my brother I am having second thoughts. Mainly what I am about to do is a departure from the plans and it involves a control system, so I am a little shy about it.

. . .

Any thoughts or suggestions????

I plan to run my rudder cable conduits as straight, true, inspection-accessible and friction-free as possible. After all, it’s a machine, not a custom house. Are there any flying examples of fuselage-imbedded cable conduits with any significant flying time on the airframe that can be used as a basis for making a mechanical assessment of this cosmedic space-saving mod? Or is it a no-big-deal go-for-it mod?

 

Side Q: What’s the final word on H45 foam, slurry or no-slurry? Admittedly just a noob, but it seems the Terf/Open-Ez plans and CP’s read all over the place on this issue. Have there been any non-slurried (Pre-CP29 builds) falling apart as a result of non slurry induced delam’s? I’m planning to slurry, but I am slurry-curious, especially near last-call :P .

Link to comment
Share on other sites

I plan to run my rudder cable conduits as straight, true, inspection-accessible and friction-free as possible. After all, it’s a machine, not a custom house. Are there any flying examples of fuselage-imbedded cable conduits with any significant flying time on the airframe that can be used as a basis for making a mechanical assessment of this cosmedic space-saving mod? Or is it a no-big-deal go-for-it mod?

 

Side Q: What’s the final word on H45 foam, slurry or no-slurry? Admittedly just a noob, but it seems the Terf/Open-Ez plans and CP’s read all over the place on this issue. Have there been any non-slurried (Pre-CP29 builds) falling apart as a result of non slurry induced delam’s? I’m planning to slurry, but I am slurry-curious, especially near last-call :P .

My main reasoning was to avoid drilling a hole through the landing gear bracket. The route through the exterior would be nearly as strait as per plans. At this point I do not think I will run the cables through the outside, but I might install the conduit there now just so I have the option at later date.

 

As far as the slurry. The CPs state pretty clearly that ALL foam should be slurryed. The video shows slurry on both types of foam as well. It does not sound like there will be a catictrofic failure if it is not slurried though.

Link to comment
Share on other sites

I hardshell (i.e. Micro the foam, let it cure, sand then glass.)

Foam is pretty thirsty. Slurry acts as both a bonding agent and a sanding sealer.

Micro all foam.(be it slurry or hard shell)

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

Link to comment
Share on other sites

Ok, I decided to go ahead and trim the landing gear brackets and bid pad to allow for installation of the engine mount extrusion. This was a feat that was pretty easy only because I happen to be in the possession of my brothers Fein tool.

 

My primary concern at this stage is if the top bolts are now to close to the edge of the aluminum bracket. Any thoughts on this would be appreciated.

 

Posted Image

 

http://flyingbackward.blogspot.com/

Flying Backward

Link to comment
Share on other sites

My primary concern at this stage is if the top bolts are now to close to the edge of the aluminum bracket. Any thoughts on this would be appreciated.

Generally, when bolting through sheet metal, the "hole to edge" distance should be more than twice the hole diameter, meaning that there should be at least "1.5 * hole diameter" from the edge of the sheet to the edge of the hole, or "2 * hole diameter" from the center of the hole to the edge of the sheet.

 

In this case, it doesn't quite look like you've got that, but on the other hand, this isn't really "sheet metal", and the bolt hole in the aluminum is unlikely to be the weak point in the system.

Link to comment
Share on other sites

....and the bolt hole in the aluminum is unlikely to be the weak point in the system.

Just my 2 cents... I may be wrong, but it would seem to me that both landing 'impact' (Sorry I'm not familiar with your landing style...;) ) and braking would tend to excert upward fores on the rear bracket - i.e. the failure mode is not likely to be tearing of bolt upwards through the (too) short edge distance...

 

Henrik

Link to comment
Share on other sites

Generally, when bolting through sheet metal, the "hole to edge" distance should be more than twice the hole diameter, meaning that there should be at least "1.5 * hole diameter" from the edge of the sheet to the edge of the hole, or "2 * hole diameter" from the center of the hole to the edge of the sheet.

 

In this case, it doesn't quite look like you've got that, but on the other hand, this isn't really "sheet metal", and the bolt hole in the aluminum is unlikely to be the weak point in the system.

 

Not to stray from the subject but I had a similar problem with my landing gear axles to get those Matcos to fit. Hope its common.
Link to comment
Share on other sites

Just my 2 cents... I may be wrong, but it would seem to me that both landing 'impact' (Sorry I'm not familiar with your landing style...;) ) and braking would tend to excert upward fores on the rear bracket - i.e. the failure mode is not likely to be tearing of bolt upwards through the (too) short edge distance...

 

Henrik

 

I tend to agree, but I wonder, if the proximety of the hole to the side might alow a crack that could cause further weakening. Still I think I will keep them, I will however make frequent inspections of these.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information