H9 Corsair flaps
 

Hi, all. I really love the way my H9 corsair flies, so I thought it deserved some flaps.

RE: H9 Corsair flaps
 

I've always loved the unique look of the F4U's flaps. They look like the feathers on a bird's wings fanning out.

RE: H9 Corsair flaps
 

some close-up video of their operation

http://www.rcuvideos.com/view_video....b44e3fdc3e9e9f

http://www.rcuvideos.com/view_video....bc3216d4774c8a

RE: H9 Corsair flaps
 

I've built the Topflite P-47, so I had some experience with building those flaps. Adtionally, I downloaded the instructions for the Topflite Corsairs and studied those. My flaps could probably best be descibed as a combination of the two methods. I started off with making a crude drawing of a flap cross-section. Then, I measured out the flap locations on the h9 corsair, and started cutting. Sorry I don't have any more construction photos or a flight video.

RE: H9 Corsair flaps
 

REALLY GOOD WORK, Craig. I have studied the full scales quite a bit, and what few people realize is that the middel flaps (on each wing, not to be confused with the ones closest to the fuselage) are more of an extension of the outer flaps. Therefore, there should be very little gap between the outer and middle flaps. And the gaps between the middle ones and the inner ones needs to be 'bridged' as you have done. This is a much better looking set-up than what is traditionally built (as per plans) on Top Flite Corsairs.

However, you might want to consider adding these posts to an existing Hangar 9 thread, rather than attempting to keep this thread 'alive'. The benefits of posting such graet ideas such as your's to an already existing thread is that:
1) established threads are more likely to remain 'alive', and will continue to recieve exposure for a longer time. In a week or 2, this one may be buried on page 2 or later, never to be heard from again.
2) It will more likely help others desiring to do the same, by consolidating ideas into one large thread, rather than multiple specialized threads.

RE: H9 Corsair flaps
 

The flaps are actuated by one standard servo for each set of three flaps. Each of the two servos operates a pushrod silver soldered into a T-shape that is inserted between the two outboard flaps (you should be able to see a glint of metal pushrod showing in some of the pictures and movies). Carving the compound curves of the flaps and aligning the hinges properly was a pain, but they work great in the air and make it easier to slow down for landings. I don't know how far the full- scale Corsairs flaps extend, but my flaps go about 60-65 degrees. Flight is very stable at full flaps with an 8% down elevator mix.

RE: H9 Corsair flaps
 

Thanks CorsairJock for encouraging comments. I noticed the difference in gaps between the flaps too. I didn't plan to have the gaps be as close to scale as they came out though. I just measured the position of the flaps as accuratly as I could, and the rest just took care of itself owing in no small part the accurate curve of the h9 corsair wing.

Good point about the existing hangar9 threads. I'll just link to this thread in on of the ongoing h9 threads. I know I've followed many great links off those threads, so the information here shouldn't get lost or detract from the other threads.

RE: H9 Corsair flaps
 

Nice Job Craig!

I've been wanting to do that to mine as well. It looks like you were able to add the flaps without recovering the wing?
Do you have any close-up pics of the bottom? I'm still trying to figure out how you hooked all that up without it all binding and where you put the servos and linkage.

RE: H9 Corsair flaps
 

Thanks, Warbird Man. Yes, I was able to add flaps without recovering the wing. But, I did remove all of the covering off the flap pieces after they were cut out. If you look closely at the second photo in post #4, you'll notice that I've started to build balsa structure inside the wing on the right side of the photo while the left side has only the original structure. The covering on the bottom of the wing on the left side of the photo actually has no balsa support under it at this point and is just a free-span of unsupported covering. After I built the proper surface structure under the covering inside the wing, I continued the spar (that originally ended at the small bay just outside the wheel well) out to the aileron. Sorry, no pictures of that.

Here are more pictures of the underside of the wing. I built the other side of the wing as a mirror image. This requires an electronic reversal of one of the servos. The hinges won't bind if you keep the hinge pins on a flap section sighted on the same line. This is hard to do perfectly on the corsair's bent wing. I just eyeballed it and got close enough for the hinges not to bind too much. The shafts of the robart hinges a little bit flexible, so that helps too. The pushrod fitted between the flaps won't bind if you leave enough space between the flap sections (only a 1/16" gap is required).

RE: H9 Corsair flaps
 

Thanks for the pics. Craig.

Still trying to figure out how you hooked the servo pushrod into the flaps. Is there some sort of travel slots cut in them?

RE: H9 Corsair flaps
 

At the end of the flap servo pushrod, I soldered on a perpendicular pin extending equally on both sides to look like a " T". Each side of the T was inserted into corresponding holes in two outboard flaps. The T-pushrod was trapped in place when I glued the flaps and hinges to the wing. Clear as mud? Maybe a couple more pics will help.

RE: H9 Corsair flaps
 

I see!!! said the blind man. As they say, "a picture is worth a thousand words".

Thanks Craig.

WM

RE: H9 Corsair flaps
 

Nice job on those flaps Craig! Those videos really show it! You know split flaps are such an important feature of the Corsair that leaving them out just doesn't do this great airplane any justice. I wonder how many more of these Hangar 9 could have sold if they would have just "approximated" what you accomplished. I for one can tell you that I would have bought one had it been offered with flaps. I just don't understand what these guys are thinking when they set out to produce a scale warbird and they leave stuff like that out! Yeah more, material, more labor, more engineering, so what, just adjust the price accordingly. Flaps are a feature that most scale warbird buffs would pay for!

RE: H9 Corsair flaps
 

Great job! They add a lot to the plane.

RE: H9 Corsair flaps
 

Craig-RCU

Vary nice work have down loaded your pic's, but have some questions Did You make any dwg's on the position of the hinges? (how much extension and angle) and on the T end of th push rod are they in wood or bushed holes with metal tubing?

thanks Bob

RE: H9 Corsair flaps
 

Thanks, all
Orvel,
Yes flaps would have been a great feature for this arf. The nicely done gull wing is what sold me on this plane. I would have been doubly sold if it had included reasonably scale flaps for a bit more cost. It's a good plane, for the price, anyhow. I think hangar9 is listening to its customers and has included flaps on two new planes in its line, the GS p-47 razorback and the spit.

Rt3232,
Here is a pic of the flap cross- section with the drilling jigs. The jigs are modified jigs from my Topflite p-47 kit. The empty slots in them are the p-47's hinge angles. The flap cradles into the flap jig for alignment, but I believe I just measured 6mm on center for the lateral placement of the wing hinge-hole. Not pictured in the drawing are the triangular shaped mounting blocks I made to support most of the wing-side of the hinge. The angular line on the flap roughly parallel to the wing-side of the hinge represents the notch cut out of the flap to accomodate the triangular-shaped mounting blocks.

I partially faced the inside of the two outboard flaps with 1/16" ply and drilled a hole in them (represented by the blue dot on the drawing) to accept the T-pushrod. The angle between the flaps changes as they extend, so a deep bushing of more than 1/16" would cause too much binding. A bushing that shallow doesn't have very much gluing area. So, I went with what amounts to a control horn slid inside the profile of the flap. The leading edge of the flap is soft balsa, so the ends of the T easily ream out any material that gets in the way.

RE: H9 Corsair flaps
 

Great job. I doubt that H9's flaps will look or performa as good as the ones that you have made here.

RE: H9 Corsair flaps
 

You are too kind, thanks.

RE: H9 Corsair flaps
 

Ok wow this is amazing i must say, i wanted to get one of these birds and now ima HAVE to get one just so i can attempt to rig up some flaps like this. amazing workmanship

RE: H9 Corsair flaps
 

Thanks, Jarrah, much appreciated
If you need any help, just ask. Also, it might be a good idea to take more construction photos than I did for the benifit of others who might be interested in doing the same. I just took one construction photo. I wasn't thinking about starting a thread when I built my flaps.

RE: H9 Corsair flaps
 

Just got an H9 Corsair for Christmas. How my daughter got it in the house "under the radar" is still a mystery. Flaps would really be the final touch on this one. Jarrah and Craig-RCU, anything you can post.t as far as a how to, and photos would be great.

RE: H9 Corsair flaps
 

Congratz preich, lucky man these are an awesome looking bird and i have wanted one ever since i saw one fly 7 or so years ago. Im not too sure how ima do the flaps but ill be taking pics as i get the work done. im sure ill have a million questions for you Craig haha. Now its off the the LHS to buy one of these suckers.

Cheers

RE: H9 Corsair flaps
 

Oh just out of intrest ill be swinging a 15x7 3 blade prop, i assume that ground clearance will not be a problem, just that i have never seen the H9 Corsair in person. Thanks

RE: H9 Corsair flaps
 

No, ground clearance won't be a problem with a 15" prop. The prop in the pictures of my plane at the top of this thread is 14". The yellow tips painted on the prop are 1/2".

RE: H9 Corsair flaps
 

Oh ok cheers mate, much appreciated.