Rebuild of 46 BC12D #8406

[senior]

Re: Rebuild of 46 BC12D #8406

Pearson: That's the exact same measurement I have but my door stands over 1/2" away from the door frame as you can see in my pic

[Pearson]

Re: Rebuild of 46 BC12D #8406

Your hinge appears to be longer than mine. In the pictures, the arm on mine is no longer than the square part that mounts on the fuselage. In the picture of yours, the arm portion appears longer than the width of the square part.

Also, I took a good look at the piece of wood that is attached to the airframe where the top of the door closes onto. It has a definite curve to it that is missing on the piece shown in your pictures.

[KTW]

Re: Rebuild of 46 BC12D #8406

You have a early 46 door with top curved with late 46 metal door frame. Early doors have all wood frames . Late doors have straight tops metal frame on fuesalge.

[senior]

Re: Rebuild of 46 BC12D #8406

You have a early 46 door with top curved with late 46 metal door frame. Early doors have all wood frames . Late doors have straight tops metal frame on fuesalge.

Well that explains a lot
So I did have a little spare time this w-end & managed to make some door frame patterns. To judge how far in or out the bottom door frame is I just pointed the outside at the lower Longeron figureing to keep the flow of the skin smooth. They are of regular plywood. I guess Ash is best... & most imposible to find, would birch plywood be suitible or ??



I had a chunk of plywood to make up a floor for the stowage compartment, I ended up doing it in two parts because after I made it to fit it wouldn't go in so I then figured two piece would allow me to remove it later if neccessary.

[Pearson]

Re: Rebuild of 46 BC12D #8406

Randy,

I think my door frames are made of either spruce or fir. I took some photos of the top and rear of the left door. From the photos you posted, it looks like your frames may be a little wider than mine, causing the door to be farther out. I don't know if this is the way you planned it or not. That would be one way of getting more elbow room once you and a friend are inside.

I think the photos I am attaching are fairly self explanatory. As you can see, the part of the frame across the top is much more narrow than yours. I hope this helps.

[senior]

Re: Rebuild of 46 BC12D #8406

Richard, thanks for the pics, I just guessed mine by kinda making the body lines flow smoothly down to the lower longerons, but now that you mentioned it, the increased cabin width would be a bonus, any reason I couldn't make it even wider??
While it looks much wider now I guess pics can be decieveing because mine measures only 5/8-3/4" wider than yours at your tape points

[Pearson]

Re: Rebuild of 46 BC12D #8406

The extra elbow room would be nice, but before you go overboard I need to tell you about my brakes.

When I first got my airplane, the brakes were almost useless. When you mashed the pedals as hard as you could, you didn't even notice the deceleration, it was so slow. My plane was based at a 1900 foot strip with obstacles at each end. In order to help the deceleration, I would open both doors as far as I could immeadiately after touchdown. It was very noticable how much quicker the plane stopped.

[Hank Jarrett]

Re: Rebuild of 46 BC12D #8406

Did I tell you guys about how my logs showed a new door on the passenger side many years ago. Did I tell you how the horizontal stab was repaired very close to the same date? Did I tell you when I re-did my doors there was evidence of damage repair to the door hinge area on both sides?
Pushing the doors open to slow you down is an old trick and works really well. Unfortunately the hinges were never designed for the loads and when the door tears off it makes a real mess down the side of the fuselage and usually hits the tail.
I imagine it is kind of hard to control the roll out with one door open and the other gone with a screaming crew on landing! The ground loop with the door off must have been a sight to behold.
I wouldn't do this little trick. You may get away with it several times, but when the odds catch up to you, you are going to have a nasty repair bill on your hands (assuming both hands are still attached).
Hank

[Pearson]

Re: Rebuild of 46 BC12D #8406

Hank,

I was mashing the brakes as hard as I could while holding the doors open, so it slowed down fairly quickly. Besides, it was better than the alternative. I only did this for a few flights because I got the brakes repaired as soon as I could. The point I was trying to make is that the more open your doors are, the more drag you have.

[Hank Jarrett]

Re: Rebuild of 46 BC12D #8406

Sometimes you gotta do what you gotta do. I would rather break the airplane than die and I would rather bend the airplane than break it.
Might want to check those doors real carefully and we will all give thanks for CG making things just a bit stronger than he had to and another friend dodged a bullet.
Hank

[senior]

Re: Rebuild of 46 BC12D #8406

The point I was trying to make is that the more open your doors are, the more drag you have.

I don't think you'd notice a couple extra inches in total overall width in drag.
There's much more to drag than just width, for instance no one can explain exactely why an Aeronca side by side Chief is faster than the tandom Champ when everything else is the same?? Besides I'd be more than willing to give up a couple mph for enough room to sit with your arms & shoulders beside you instead of hunched up in front or worse one arm hugging some guy beside you than smells of BO from drilling ice fishing holes

[N96337]

Re: Rebuild of 46 BC12D #8406

The Granville brothers (GB fame) found that the most aerodynamic shape is a raindrop....think about it.
JH

[Hank Jarrett]

Re: Rebuild of 46 BC12D #8406

Well, it's actually the traditional shape of a tear or rain drop. ACTUAL rain drops look more like bagels or a red blood cell when they fall! They are a TERRIBLE aerodynamic shape for low drag and represent the lowest energy form for a falling fluid in a droplet form.
Hank

Just another totally useless bit of information from someone who hangs around with wind tunnel nerds too much.

[N96337]

Re: Rebuild of 46 BC12D #8406

There ya go... I knew there was a better way to explain it. Thanks Hank.
JH

PS ....and I learned something about blood and bagels!

[senior]

Re: Rebuild of 46 BC12D #8406

Forginga ahead...S-L-O-W-L-Y

Skylight frames made up.
1" width on the sides to allow room for flashing & Lexan mounting.



I have raise the front height 1/2" over stock, the rear I made the same profile as the front.



That gave me almost 1/2" clearance over trim lines. I may gently lower the front & rear profile to 1/4" clearance in the center, just enough for a rubber shim support for the Lexan.



Still fidling with the doors. Made a mock up wood frame but even at 1/2 thick it's to tight on the door & I'm afraid of the frame will become too weak any thinner, after all I'm not quite as supple as I used to be & may have to drag & bang body parts on entry & exit! Soo, I switched to the metal frames that came with the plane, they seem to fit nice with only 1/2" wood shim behind one side, the hinges are totally out of wack but I can refit those easy enough.
Be happy when other project is finished so this one can move to front & centre.