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  #11  
Old 08-03-2017, 12:57 PM
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DanH DanH is offline
 
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Originally Posted by foxhound57 View Post
A totally wrong assumption on your part!
Perry, I realize you're proud of your creation, but David is a vastly experienced aerospace structural engineer. Exactly what wrong assumption did he make?
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Dan Horton
RV-8 SS
Barrett IO-390
  #12  
Old 08-03-2017, 01:01 PM
David Paule David Paule is offline
 
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Originally Posted by foxhound57 View Post
A totally wrong assumption on your part!
If the forebody really has been lengthened, for any reason, that has a destabilizing effect. There might be mitigating factors or perhaps the wing-nose distance hasn't been changed. I'm not a -8 guru.

Could you please discuss this a bit?

Thanks,
Dave
RV-3B, now skinning the fuselage
  #13  
Old 08-03-2017, 02:13 PM
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rv7boy rv7boy is offline
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Talking Back to the Future!!!

Surely this is a typo...

"This RV8 was issued its Transport Canada C of A, on 21st December 2017..."

If not, then I think I see a DeLorean in my driveway!!
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RV-7 Wings
KDCU Pryor Field
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N79599/APRS Automatic Position Reporting System

“Certainly, travel is more than the seeing of sights;
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  #14  
Old 08-03-2017, 04:37 PM
foxhound57 foxhound57 is offline
 
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Location: Gold Coast Australia
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Originally Posted by tfriendshuh View Post
Super cool - thanks for sharing!

Talk to me about canopy - was the tip-up easier/better option to stretch than a slider or was that also personal preference?

thnx
Hi Tim

The Turtle deck is the limiting factor for the Canopy given its profile and length. If I could have figured the Engineering out here, I would have preferred to go to a Slider (looks way cooler) or even and aft Lift-top. There was a lot of work in stretching the Show-Planes frame.

However, ease of entry and exit is one benefit of the Tilt-over canopy. The design allows for unrestricted forward visibility and improves cockpit ventilation while taxying. The design has a removable instrument access cover as well, that allows a clear view and access for maintenance of your forward instruments/avionics if required.

Todd’s Canopy made the extended Canopy for me. PM me if you have any further questions.

Last edited by foxhound57 : 08-03-2017 at 06:01 PM.
  #15  
Old 08-03-2017, 05:52 PM
foxhound57 foxhound57 is offline
 
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Originally Posted by DanH View Post
Perry, I realize you're proud of your creation, but David is a vastly experienced aerospace structural engineer. Exactly what wrong assumption did he make?
Hi Dan

Happy to discuss all elements of the build and our challenges over the four years of construction. Especially if that assists fellow RV builders, who may want to achieve variations to their own build.

Yes, we are very proud of what our little team has achieved.

Alas, I have noted on some threads on Vans AirForce forums, the arrogance by some constituents to post blind (uniformed) statements and to challenge rather than to inquire or simply politely ask a question showing a degree of "self-importance" I do would not wish to engage with.

Noting that your “friend” missed the fact that my daughter is a degree qualified Aerospace Mechanical Engineer and that I engaged another Aeronautical Engineer and a DAR, might have most informed individuals assume that we mapped out all aspects and contingencies of this build. In fact, the aircraft is more stable than an ordinary RV8.

Blind Freddy can determine that from simple Aerodynamics (i.e. longer lever arm - the same surface area of the original control surface – simple mechanics). Given I was not going to enroll the aircraft and myself in the next world-aerobatics championship, this is not of a concern.

It performs nicely in all Aerobatic Maneuvers.

Finally, I used a highly qualified Test Pilot for most of my Flight Testing in Canada. His Professional Opinion (someone who flew the aircraft through all flight regimes) was that he could note No difference in handling between this RV8 and an ordinary RV8.

I hold some test-flight qualifications myself and although I have only flown two RV8’s, I find this aircraft almost indiscernible (i.e. no difference) in-flight around the all three axes to an ordinary RV8.

The only real aerodynamic challenge was the speedbrakes. They were far too efficient for the NACA type wing design. However, modification to the face plates rectified that little problem.

Yes, we did our homework!
  #16  
Old 08-03-2017, 05:54 PM
foxhound57 foxhound57 is offline
 
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Quote:
Originally Posted by rv7boy View Post
Surely this is a typo...

"This RV8 was issued its Transport Canada C of A, on 21st December 2017..."

If not, then I think I see a DeLorean in my driveway!!
This RV8 was issued its Transport Canada C of A, on 21st December 2016 AND was issued its Australian C of A, on the 21st July 2017. VH-FSX next chapter is an appointment with the Paint Shop!

Thanks, Don - Typo Corrected!
  #17  
Old 08-03-2017, 07:03 PM
David Paule David Paule is offline
 
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Thanks for the discussion. Your original description was solid on the structural and similar characteristics but didn't get into the aerodynamic aspects. It was obvious that you had qualified people on the project and if you had said something about this initially I wouldn't have asked in the first place.

I wasn't trying to set a trap or promote myself, merely to learn how you worked that out. It's one of the things that does sometimes catch the unwary. While your initial reply wasn't encouraging, I do appreciate your further comments, and am glad that you succeeded in your goals.

Also - thanks, Dan. I'll admit to half-vastly but not the full vastly.

Dave
  #18  
Old 08-03-2017, 07:28 PM
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Quote:
Originally Posted by foxhound57 View Post
Hi Dan

Happy to discuss all elements of the build and our challenges over the four years of construction. Especially if that assists fellow RV builders, who may want to achieve variations....
I'm curious about the gear towers, having had a recent discussion with another builder about bolting on longer legs. If I understand correctly, you've gone with both longer legs and a gross weight increase. What can you tell us?
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RV-8 SS
Barrett IO-390
  #19  
Old 08-04-2017, 12:18 AM
foxhound57 foxhound57 is offline
 
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Originally Posted by DanH View Post
I'm curious about the gear towers, having had a recent discussion with another builder about bolting on longer legs. If I understand correctly, you've gone with both longer legs and a gross weight increase. What can you tell us?

Hi Dan

The standard RV8 gear legs were not suitable. So, we had Grove manufacture a custom one-piece landing system for this aircraft. Precision CNC machined with Gun-Drilled Brake Lines. This allowed for the MTOW increase using the cross-axil support. (Not dissimilar in shape and performance of the Zenith CH801 landing gear manufactured by Grove). Subsequently, we achieved a slightly wider track additionally fitting uprated Wheels and Larger Brakes in consideration of the Static Load Rating, Braking Torque and Kinetic Energy absorption required.

Given the nature of unimproved strips and ALA’s in Australia the aircraft benefits from the extra height and larger wheels. Notably, I have to discipline myself to keep my Big Fat Feet away from the brakes being a Tailwheel aircraft until the appropriate phase in the landing!

Hindsight being an exact science, I could have decreased the arc of the gear leaving the fuselage as this gave the Innovative Wings team a challenge in designing a fairing to fit. However, RV10 Wheel Pants cover the Wheels and Brakes nicely.
  #20  
Old 08-04-2017, 08:13 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by foxhound57 View Post
The standard RV8 gear legs were not suitable. So, we had Grove manufacture a custom one-piece landing system for this aircraft.... additionally fitting uprated Wheels and Larger Brakes in consideration of the Static Load Rating, Braking Torque and Kinetic Energy absorption required.
One-piece gear for the -8 has been a previous forum subject. Other than the additional weight, there does not appear to be a downside ("Primum non nocere"). The upside would be increased capacity in a vertical drop, and better resistance to severe side forces as seen in a ground loop (a good ground loop wrinkles an RV-8 fuselage at the towers). How much improvement depends on details, which is where you and your daughter enter the picture.

1. Did you retain the inboard clamp block and AN5/AN7 bolts each side?

2. It's been shown in service that the standard gear length can strip the supplied nuts off the outboard clamp bolts...certainly evidence of significant load when force is applied to the axle in the fore and aft plane (brake application, or running the wheel into a hole, or a pavement edge). The one-piece gear would not help in this regard. The problem would be magnified by a gear leg extension. That was the crux of my discussion with another builder; his engine choice suggests a longer prop, and thus a lengthened gear, as you've done here. Could you share your daughter's analysis of the gear tower and clamp bolt strength margin?

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RV-8 SS
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