Juice

I'm almost finished building a 1/8 TF Corsair. I'm using robart retracts with the oleo struts. I originally planned on having functional main gear doors. But now I have to give up on the functional gear doors. Any method or idea I tried to make those doors close didn't work.

So now I have big rectangular openings on the bottom of the wing, 4.25" x 4.5" each (see attached pic). Will these big wide open wheel wells affect the flight characteristics (lift)? Should I re-sheet the square wheel wells then cut out smaller round wheel wells like all other TF Corsairs I've seen (for smoother airflow under the wing)?

I'd be good to keep them rectangular. I may want to give Dionysusbacchus' gear door method another try at a later date. But for now I just want to get this thing finished and flying.

Thanks,
Juice

Slug

The full size aircraft flew with rectangular wells, I don't see why the aerodynamics of a model should be any different. I have the Brian Taylor Corsair plans around somewhere, I think that has scale rectangular wells.

If you want to tidy things up in the short term how about a cover plate with a circular hole, attach it to the surface with a few small screws so it can be removed easily later on.

Simon.

dionysusbacchus

My Feedback: (25)

Hey Juice, nice to see ya back. I have found through others trials and tribulations with the TF Corsair that 4.25" is not wide enough of a wheel well to clear a 3.5 tire. The wheel wells on my Royal Corsair are 5" wide. I am convinced this is your problem. I would just cut it as wide as you need and then add the ribs needed for support.

This can all be done even after finishing the plane. I have flown Corsairs with a 5" open wheel bay with no problem, so you can just finish it as it is and fly it. I have seen guys show up at the field with planes that defy all know laws of aerodynamics, and they fly the darn things . I don't have the respect for aerodynamics that I had in the past after seeing these things fly, we tend to worry to much I think.

I'm almost caught up with you on my project, these final details are slowing me a little though

Luke

CorsairJock

My Feedback: (90)

If I were in your situation, I would use blue foam blocks to temporarily fill the void/ round out the wheel wells. Specifically, I would make 8 blocks, about 2" x 2" x 1" (OR, 2 pieces, each fitting snugly in a well), attach them to the corners of the wells, dremel them to make a round opening, apply some masking tape over the already finished area to prevent sanding damage, then sand to match the contours of the wing underside. This foam is very easy to work with, sands easily (but makes a mess, do it outside), can be filled with Model Magic/ Hobby Lite, and could be removed if/when you decide to add the main gear doors. You will need to paint it with foam safe paint, unless you apply a layer of glass cloth which would add some dent resistance and make a smooth surface.
Altho the full scales have these big openings, I do believe that they create a lot of 'dirty air', drag, and reduce lift. Therefor, I believe the flight characteristics will be better , even if only slightly, if you fill in the voids.

BTW, to those who are interested in my vacu formed m.g. openings. Since stating my intent to have Wing Mfg. make these widely available, I have acquired a D&B Corsair kit. I consider this 70's kit to be the Cadillac of 1/8 scale Corsair kits, from a scale accuracy and details point of view. Having owned one in the past, I remembered that this kit came with vacu formed m.g. openings, and so I held off having Wing make them from my plug until the D&B kit arrived, thinking they were probably better. Now that the kit has arrived, I have decided that I prefer my plug, and so I am again working with Wing Mfg. to have them produced. They should be available by the end of May.

Also, my gallery has been updated with more pics of my Top Flight Corsair, and it has now been flown. 3 dead stick landings (all with wheels up, as I have discovered this is the best way to dead stick these in) and one good, engine running wheeled landing. The Saito .72 needs some more adjustments after setting for about 1 1/2 years. It ran good on the ground, got richer in the air. I think some old fuel must have gunked things up, then it cleaned itself out.

F4u5

My Feedback: (81)

Leave 'em square...will make no difference over round

Juice

Thanks for your responses guys.

I'm back, but only in spirit. I haven't spent any time in the workshop in a month and probably can't get back in there for another month more. Work gets in the way of the hobby, but unfortunately, I have to work to finance the hobby. On top of than, my out-of-town girlfriend is in town. Then, once I get back to the workshop, I need to do a major repair on my Super Sportster that was involved in a mid-air collision last month. So as you can see, I'll be pressed for time to get this Corsair in the air before the end of the flying season.

Luke... on your website, you mention that you had a P-47 that was originally monocoted, then the monocote was removed so you can glass it. I'm also thinking to do a temporary monocote job for the summer. Then when the flying season is over, remove the monocote and glass it. How did you remove the monokote and glass the "hinge areas"? Did you have to remove the control surfaces?

Juice

dionysusbacchus

My Feedback: (25)

Hey Juice,

For the best job, I cut the control surfaces off at the hinges. If you have problems getting the hinges out just sand them smooth and put a new one next to the cut one. Of course the P-47 was an old kit, built when they first came on the market in 1979 I think, the hinges were no problem to cut. I know you don't have the option to move the Robart flap hinges, but those can be removed with a brass tube in a drill. Get some brass that will fit over the hinge, sharpen the end and drill! Fill the hole with balsa and re-drill. Don't go crazy with the iron. Some times monokote can be overheated and it will really bond to the wood, permanently! Use a heat gun and a soft cloth for most of the work, and the iron for the edges. This will make it easy to remove later.

Sorry about the gear doors not working, I have updated my site to help other TF builders. The TF kit's ribs in that area are not wide enough, certainly far short of scale size in width. I was really looking forward to seeing doors on your plane, I figured if anyone could do it you could. But maybe after the flying season.

I don't worry about flying season here! When the tide is out I'm thinking of flying my Corsair off the beach and get some cool pictures! It is tempting! Daydreams again!

Luke

phayd

Juice, don't give up on the doors. Dionysus' method works flawlessly.

The key is using the least amount of travel that you can convert into useable torque. This allows you to get the tire inside the bay before the doors begin closing. If the doors close too early, the wheel will bind the mechanism.

I ended up with the ball links at almost 1/2 the distance to the end of the actuator rod.

The horn is epoxied to the door, then the door is fiberglassed with the horn in place. Hopefully this will be sufficient.

I will attempt to get pictures of it after I finish the inner bay.

BTW, my bays are ...

...getting my ruler...

... drum roll...

...4 1/2 inches wide. I am using robart scale wheels, although I don't know the size. I sispect it is 3 1/2 inches, though.

dionysusbacchus

My Feedback: (25)

Great job phayd! You da man!

phayd

The other thing I meant to say is that my variation has a smaller actuator, which are mounted 1/2 way between the top and bottom of the wing. My ball links are on the outside of the actuator, which means that I had to bend the actuator to fit parrallel with the wheel until it is clear of the wheel.

The added benefit here is that I have a positive close on the doors, and I have not yet installed the springs. I will be installing springs, because I want the open state to be as definite.

I am using regular hanger wire for my actuator arm. Currently, I like the flexibility, which means that it has a little give before anything might bind.

Hanger wire also allowed me to modify the shape to exactly what I need to get under the wheel, and also curve the end of the bar to match up with the top of the wing.

Juice

Go phayd! How your Corsair coming along? Keep us updated, with picture if you can, on you gear doors.

I'm not going to give up on the doors. Now that I know I can safely have square wheel wells open all the time, I can plan on adding the doors in the off season.

Juice

dionysusbacchus

My Feedback: (25)

I'm happy for your success phayd, but I am still going to recommend that TF owners widen the wheel bay by 1/4" on both sides so that the bay is at least 5" wide. This is extremely easy to do, and even more so when you are just framing up the wing. I am using strips of 1/16" ply on the bay sides so that I can use a small screw to hold the hinge. On the doors all that is needed is some 3/32" balsa over the hinges and control horn.

Luke