Van's Air Force
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Rocket Wings on a -7
- Thread starter Razor
- Start date
pierre smith
Well Known Member
The usual deal is....
...that they cut off the last rib bay but use all the ribs, just spaced closer together. I have ridden in two Super 6's and don't know of any "Rocketized" -7's. Cruise is around 230 MPH,
Best,
...that they cut off the last rib bay but use all the ribs, just spaced closer together. I have ridden in two Super 6's and don't know of any "Rocketized" -7's. Cruise is around 230 MPH,
Best,
Kahuna
Moderatoring
What do you mean rocketizing?
Neither the EVO nor the std F-1 roket wings have much chance mating with the 7.
Not sure what your asking.
Yes there is a Super 7 flying. Not sure if it meats your rocketizing question.
avengingangel
Well Known Member
intersting. I kind of think you'd want the extra hp of the 540 also up front if the wings were chopped.
The RV-4 wing spars meet in the middle of the fuselage. The RV-7 spars do not. The spars are quite different. No way will they interchange.
Kyle Boatright
Well Known Member
I almost answered the question that way, but reinterpreted the question. No doubt that the -4 and -6 wings cannot mate to a -7, but you could modify a -7's wing by to "rocketize" it. Presumably, the modification would include eliminating one bay from the wing, moving the flaps inboard, and a bunch of other modifications. Loads 'o fun. ;-)
Sid Lambert
Well Known Member
The rocket wings are 1 rib bay shorter but have the same amount of ribs. You'd need to order your wing kit unpunched so you could space the ribs evenly after shortening the spars.
smokyray
Well Known Member
Some are longer than others...
Ryan,
The Harmon Rocket II was John Harmon's effort in to make a "better RV4" after his 180 C/S RV4 became too small and slow for traveling.(The RV8 wasn't in existence yet, nor was the 7,9,10,12). John went to work modifying an existing RV4 kit to his new specifications. Early modifications produced the HR1 which was a "Super Three" and finally engineered the HRII, a "Super Four", but really an entirely new airplane.
John began with a standard RV4 kit then lengthened, widened and added a turtle-deck to the fuselage and 040 was used judiciously up front. Shortening the wings but retaining the same number of ribs and the laminated spar from the RV4 (and RV6) slightly increases wing loading and adds strength. RV4 aileron span, RV4 tail, longer titanium gear, extended baggage and of course, the IO-540 up front is the Le piece de resistance. Mark Frederick was an early HR2 builder who refined the Rocket design into the F-1. He later produced a fabulous kit that rivals any experimental aircraft kit out there.
The RV7 and RV8 use a very different wing from the RV4,6 and HR2 featuring a one piece machine billeted spar, CAD design, pre-punched holes and an overall refined kit. I refer to the post RV6 kits as RV's, The Next Generation.
Three Super Six's (I know of) have been built, Bob Mills being the only one I have seen up close and it is nice. Bart D. built a nice Super Six 2+2 that is still flying. I just finished a Six hybrid for my Dad using RV4 wings and tail modified to fit the Six fuselage. It flies great!
My Rocket was an early HR2 built by one of the Bakersfield Bunch and is still an absolute hoot to fly well into it's fifteenth year. It's the closest thing to the F-16 I can afford to fly out of my back yard. If you're truly interested, buy a set of preview plans or do like I did way back in 1989, buy an RV4 tail kit!
History lesson complete
Smokey
HR2
www.harmonrocket.com
Ryan,
The Harmon Rocket II was John Harmon's effort in to make a "better RV4" after his 180 C/S RV4 became too small and slow for traveling.(The RV8 wasn't in existence yet, nor was the 7,9,10,12). John went to work modifying an existing RV4 kit to his new specifications. Early modifications produced the HR1 which was a "Super Three" and finally engineered the HRII, a "Super Four", but really an entirely new airplane.
John began with a standard RV4 kit then lengthened, widened and added a turtle-deck to the fuselage and 040 was used judiciously up front. Shortening the wings but retaining the same number of ribs and the laminated spar from the RV4 (and RV6) slightly increases wing loading and adds strength. RV4 aileron span, RV4 tail, longer titanium gear, extended baggage and of course, the IO-540 up front is the Le piece de resistance. Mark Frederick was an early HR2 builder who refined the Rocket design into the F-1. He later produced a fabulous kit that rivals any experimental aircraft kit out there.
The RV7 and RV8 use a very different wing from the RV4,6 and HR2 featuring a one piece machine billeted spar, CAD design, pre-punched holes and an overall refined kit. I refer to the post RV6 kits as RV's, The Next Generation.
Three Super Six's (I know of) have been built, Bob Mills being the only one I have seen up close and it is nice. Bart D. built a nice Super Six 2+2 that is still flying. I just finished a Six hybrid for my Dad using RV4 wings and tail modified to fit the Six fuselage. It flies great!
My Rocket was an early HR2 built by one of the Bakersfield Bunch and is still an absolute hoot to fly well into it's fifteenth year. It's the closest thing to the F-16 I can afford to fly out of my back yard. If you're truly interested, buy a set of preview plans or do like I did way back in 1989, buy an RV4 tail kit!
History lesson complete
Smokey
HR2
www.harmonrocket.com
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avengingangel
Well Known Member
I just love the cockpit and visibility is awesome. Really unless you sit in a rocket you won't understand that it's really nothing like the 4. I absolutely love the canopy, it's so much lower than the 4. I have the 8 tail on mine.
Just out of curiosity could the wings not be modified on the 7 instead of trying to put 4 wings on it. Sorry, but i'm not sure if anyone would really want to do this anyway, but if someone wanted to take on the idea of smaller wings and bigger hp in a 7.
Just out of curiosity could the wings not be modified on the 7 instead of trying to put 4 wings on it. Sorry, but i'm not sure if anyone would really want to do this anyway, but if someone wanted to take on the idea of smaller wings and bigger hp in a 7.
Why not just eliminate the tip rib?
What is the necessity of retaining the same number of ribs in a shorter wing? I'm not prepared to do it (at least not yet) but if I were to take it on I would basically just cut the wing off on my RV-6A just outboard of the next to last rib and reestablish the the tip interface. The most simple back of the wing solution would be to cut off the aileron outboard end and rehang it exactly as it is at the current tip. I would no doubt notice a reduction in roll authority but for racing I think it would be fine. The full stock flap length might help recover some lift at the proper setting for landing. These are just thoughts and do not endorse the idea of actually turning a perfectly good airplane into a special purpose airplane that is more difficult (impossible?) to fly and worthless on the resale market.
Bob Axsom
What is the necessity of retaining the same number of ribs in a shorter wing? I'm not prepared to do it (at least not yet) but if I were to take it on I would basically just cut the wing off on my RV-6A just outboard of the next to last rib and reestablish the the tip interface. The most simple back of the wing solution would be to cut off the aileron outboard end and rehang it exactly as it is at the current tip. I would no doubt notice a reduction in roll authority but for racing I think it would be fine. The full stock flap length might help recover some lift at the proper setting for landing. These are just thoughts and do not endorse the idea of actually turning a perfectly good airplane into a special purpose airplane that is more difficult (impossible?) to fly and worthless on the resale market.
Bob Axsom
pierre smith
Well Known Member
Sure...
I don't see any reason why you couldn't cut off the last bay of a -7, just like they did the -6 and then, your choice to either leave the aileron the stock length, or shorten it so you could have more flap length.
All the Super -6's I've been around have added around 8-10" to the rear fuselage to compensate for the bigger motor and CG issues.
They also add 8" of length to the cowl to accomodate the extra two cylinders.
You can either buy Harmon tanks or get one more fuel tank skin, cut it in half and add that to each side for a total of 60 or so gallons, still 4+ hours endurance.
Best,
I don't see any reason why you couldn't cut off the last bay of a -7, just like they did the -6 and then, your choice to either leave the aileron the stock length, or shorten it so you could have more flap length.
All the Super -6's I've been around have added around 8-10" to the rear fuselage to compensate for the bigger motor and CG issues.
They also add 8" of length to the cowl to accomodate the extra two cylinders.
You can either buy Harmon tanks or get one more fuel tank skin, cut it in half and add that to each side for a total of 60 or so gallons, still 4+ hours endurance.
Best,
Mike S
Senior Curmudgeon
Welcome to VAF!!!!
Ryan, welcome to the force.
As you can tell, this is a great place to find out info about things RV---or Rocket.
As I see it, and this is strictly my opinion, if the 6 can be successfully "Rocketized", then the 7 should be a candidate also.
Biggest concern I see, is the amount of prefabrication in the 7, which will actually be a determent to the changes like lengthening the fuse, and the already mentioned rivet hole spacing for the wing skins.
Good luck, keep up the research, and build what you want------just be safe about it, and have a knowledgeable
person review any modifications, (that is unless you are an aero engineer yourself).
Ryan, welcome to the force.
As you can tell, this is a great place to find out info about things RV---or Rocket.
As I see it, and this is strictly my opinion, if the 6 can be successfully "Rocketized", then the 7 should be a candidate also.
Biggest concern I see, is the amount of prefabrication in the 7, which will actually be a determent to the changes like lengthening the fuse, and the already mentioned rivet hole spacing for the wing skins.
Good luck, keep up the research, and build what you want------just be safe about it, and have a knowledgeable
person review any modifications, (that is unless you are an aero engineer yourself).
N941WR
Legacy Member
Bob,
By reducing the spacing of the ribs, you strengthen the wing.
As someone mentioned, Harmon also increased the thickness of the forward skins to carry the extra load of the larger engine.
Probably a little bit especially in torsion, but ...
The wing is automatically stronger when you reduce the span. If you are going to hang a 540 on the front you may be concerned about peeling the wings off but you are going to have to get a lot more speed that you are going to get from the span reduction alone to get into the worrying zone I think. I would consider one of the 390s and run in the RV Gold class if I were going this way. I don't know about the RV-7s etc. but the RV-6 is built like a one piece wing similar to the F-4 - H@11 for stout! Thicker skins would give more strength in more ways than one but the extra rib would seem to do very little in the bending mode.
Bob Axsom
The wing is automatically stronger when you reduce the span. If you are going to hang a 540 on the front you may be concerned about peeling the wings off but you are going to have to get a lot more speed that you are going to get from the span reduction alone to get into the worrying zone I think. I would consider one of the 390s and run in the RV Gold class if I were going this way. I don't know about the RV-7s etc. but the RV-6 is built like a one piece wing similar to the F-4 - H@11 for stout! Thicker skins would give more strength in more ways than one but the extra rib would seem to do very little in the bending mode.
Bob Axsom
N941WR
Legacy Member
Correct but the extra rib would help reduce twisting and with the extra beat of the bigger HP engine and speed, maybe he was worried about flutter.
Why don't you look him up and ask him why, I'm sure he would give you a straight answer.
I Don't Think So
I understand why just as I would understand why a designer would incorporate wing struts into the design. I would just not do it with my goals, I believe my requirements can be satisfied without the rib or thicker skin. If I increased the requirements and incorporated a much larger engine I would have to consider a different airplane.
Bob Axsom
I understand why just as I would understand why a designer would incorporate wing struts into the design. I would just not do it with my goals, I believe my requirements can be satisfied without the rib or thicker skin. If I increased the requirements and incorporated a much larger engine I would have to consider a different airplane.
Bob Axsom
