Window Frame Detail

[Bcone1381]

The photo shows a view of the left side of the fuselage at the upper aft corner of the left main window that opens and closes, and the beginning of the top aft window frame. The vertical piece of sheet metal is the fuselage former. The horizontal piece clamped in place is the top of the rear window frame.

Screen Shot 2017-04-29 at 10.13.27 PM.pngScreen Shot 2017-04-29 at 10.17.09 PM.png

Is the Window Frame secured on the outside or the inside of the fuselage former?



IMG_3149.jpg

[Mark Goldberg]

Hi Brooks. I have been trying to think how I did mine but my planes are not here now so I can not just go out and look. First of all - I think you have the "flat" side outward. I would put the side of the window frame with the joggle for the plexi facing outward. As far as your question - I think I would trim back about 1/2" of the side with the joggle in it (with the joggles side facing outward) and attach just the flat side to the inside of the vertical former flange. You will put a little vertical trim strip on the front side of the window frame to cover up where the plexi ends.

In a question like this - what you have to visualize is how the fabric would look good. The fabric comes down from above and get glued into the window frame. So I would check what I recommended and see what would look best. You do not need real aircraft fabric to try this out. Any piece of old sheet or some kind of thin fabric would show you the same thing. Mark

[Flygirl1]

Hi Brooks, Dennis and i cut the window frame around that former otherwise you will have a bump in the fabric. Also we had the discussion with Mark about which side was "out" and which was "in" on the frame itself, after the fact. ;-) According to Mark our window frames are inside out. I guess that's up for debate. It seemed to make it easier to lay the fabric on a flat piece rather then a bumped piece. They look OK the way they are and besides that we had already cut them to fit so that ship had sailed. Also we shortened it length wise, cut it in half at the rear of the frame and added a small piece to make it taller. Looking at your photo I think that is only one side of the frame? It appears you have not rivited the two half's together yet? D.

[Bdflies]

Initial read of your question, left me excited that I could offer Brooks some advice! Fully understanding the question, I realized that this is an area that I ventured from Bob's design. I didn't use the aluminum frames, or the former, above the lower window edge. I've got pics, but they wouldn't help you much.
I will offer a bit of my approach that worked; I completed the folding window installation, complete with formed aluminum edge moldings around the plexiglass. When the folding windows were complete, I mounted them, to have top and bottom edge references to place the rear windows. With the folding windows in place, I was able to place the rear frames to match the lines of the front.


Bill

[Bcone1381]

Today I made some progress at getting the window frame lined up.

Denise, The Window frame came riveted together, but my photo does not show it very well. Your rear window looks nice. You and Dennis did a great job.

Mark you are right, the I did have the flat side of the window frame facing outward. I swapped sides, and am progressing with it facing inward. It helped me to understand the end goal regarding the appearance after the fabric is installed. I also like the idea of removing a small part of the joggled edge of the window frame and securing the flat side of the window frame to the fuselage former.

Tabs are Welded to the fuselage tubing that allow me to the to build structure for window frame attachment. It seems prudent to use some of the spare aluminum stringer material for this window framing.

Brooks Cone
Patrol #303 Kit Build

[Mark Goldberg]

Brooks, I think what is intended is use the fuselage stringer for the bottom window frame support (pop rivets) and an aluminum 3/4 x 3/4 angle (1/16" thick) of 6061T6 along the top of the window frame. There you could use pops, screws and nuts, or other ways to attach it. Mark

[Bcone1381]

This is what I ended up with for my window install. I really like the 3/4 " angle that Mark recommended. It runs across the top behind the frame, and a portion of the bottom of the window frame. This install allows me to slide the window in when the time comes, then I will place a piece of trim to close things up tight.
IMG_3205.JPG

[svyolo]

I am mounting the rear windows, and looking at the size of them (small), I was thinking I could get away with thinner glass than the .118" I am using for the front door windows. Anybody use anything thinner on the rear windows?

[Mark Goldberg]

I would not go thinner than .090. It just gets so wavy with vibration that thinner bothers me. Mark

[svyolo]

I was at SNF the first two days last week. I didn't see any BH's, but lots of other bush planes. A lot of them had at least a single curve in the glass, if not slightly bubbled out, and used much thinner glass.

But I will go with .09. Thanks. I am in get-er-done mode. No side projects.

[rvanbladeren]

My side window frames look just like yours Brooks but now I don't know how to get the pilots window frame to lay flat since the aft edge will be about 1/8" proud compared to the other three sides after the plexiglass and retainer piece is installed. Any suggestions?

Ron
P131

[davzLSA]

I think that is one place where the plans and the book that comes with them is severely lacking, there is just not enough detail in either one to really understand how it is supposed to go together. It would be nice to have more clear instruction and some good pictures or even a line drawing to show the detail. But I have just resigned myself to the fact that this is an experimental airplane and I have plenty of opportunities to experiment. Otherwise it would just be another match hole assemble kit?

[Bcone1381]

We are home builders; we work together to get ideas and improve on them. Here are photos I took of some other aircraft. Most are bearhawks. The first four I believe show Bob Barrows' Patrol. Notice Bob's right window trim (first photo) almost has a edge rolled type bend to it...very slight, looks about 3/4" wide behind the rivets that secure it to the tubular frame. That slight bend is absent from the left window frame.

IMG_3628.jpgIMG_3734.JPGIMG_3733.jpg
IMG_3629.jpg

[Bcone1381]

Here are two images of other Bearhawk. The yellow is Donna's, I cant recall the builders name of the Blue one, but its a real nice LSA.

The next two show an EAB Carbon Cub. Notice they didn't use a sheet metal frame on the outside, rather painted the frame onto the plexiglass window of both the hinged front and fixed rear windows. Something to consider for a window frame fabricated from square tubes like the Carbon Cubs (I think the four place too) but not for the Patrol's tubular constructed window frame.

The last three photos were taken at Oshkosh of a former Grand Champion EAB cub variant. The joggle he used gives it a nice finished look.

Do nothing and paint it.....fabricate a joggled trim piece, or something in between....those are the ideas I've found so far.


IMG_3795.jpgIMG_5743.jpg
IMG_5791.jpgIMG_5792.jpg
IMG_3692.jpgIMG_3695.jpgIMG_3693.jpg

[Bcone1381]

One last thing about choices. I just showed different techniques to accomplish a job. I would bet that a bunch of guys (me included) are going to say right now "I'm going to do mine like that Grand Champion did it."

All the methods got the job done. One has been to Alaska, Idaho back country, has maybe a thousand hours and maybe multiple thousands of hours on it. One aircraft won a trophy.

So, I need to remind myself, and maybe a few readers here "Your not building a show plane, and you will never get yours to Alaska, or tell stories like Battson, or experiment with aerodynamic improvements if you try building a show plane."