very minimal bubble window with thinner windows

[Westward_Flyer]

Hi all,

I have been considering making the windows with a very minimal bubble (1/2 inch) in order to get away with using a thinner material. My assumption is that the bubble would reduce or eliminate the drumming seen with thinner windows. Does anyone have any experience or advice regarding this? I figure it would save 1-2 pounds per door which is nothing to sneeze at.

Thanks!

[Nev]

I’ve done the same thing on my front doors, although yet to install the perspex. I think it should reduce drumming and stiffen up the window generally. One possible downside is that it does restrict the door from opening right up against the wing underside but I can live with that. A plus is that it increases shoulder room quite noticeably.

It’ll also be interesting to see what effect the outward curved shape (very similar to an aerofoil) does if I try to open the door in-flight. I suspect it will try to pull open against the wing and probably hold itself in the open position.

I haven’t weighed the doors yet and they’re not completely finished. But they are still very light and will be very similar weight to the original split door. The original lower door has a larger diameter diagonal brace to support the door vertically, which is not needed on the gull-wing doors and the stiffening is largely derived from the skin.

[Peter Bishton]

Nev
can you please post a few photos of your doors
regards
Peter
4 Place plans # 1186

[Nev]

Here you go Pete. I’ll be installing gas struts at the aft top of the door. The original steel hinges appear to be quite good for this as it allows a smaller gas strut - places more stress on the hinge. I’m planning to cover just the lower interior door panel with thin .028 Kydex.

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B3BF9DCD-5AC1-4415-9379-01D5072F6025.jpeg

This one shows the outward curve built in (probably need to zoom in on the cross member) :

1FB3C2A4-9F1E-413B-BA13-4601E51327C0.jpeg

5FB7D258-24B8-40AD-82C6-18738BCF7BCD.jpegE98DFDFA-A465-4CBD-86E3-910C2F2E7AF0.jpeg

[svyolo]

You just used the original kit upper door/window as the top half of your door? If I get around to making gull wing doors I was thinking along the same lines. Looks good.

[Westward_Flyer]

Thanks Nev, I've been following your build closely both on here and on youtube and am a big fan.
I'm sure your built in bubble/radius will offer similiar stiffness compared to a bubble window put into a flat door. I'm had also put some thought into the shape of door with a bubble window and think it will act like an airfoil as well. As long as it's not strong enough to stress the hinges too much (which I really doubt) then it should just help hold the door open like you mentioned. Also planning on putting in a gas strut or two. Thanks again for sharing your advice and build!
-Kylan

[Nev]

Thanks Kylan !