Bubble door installation

[HansLab]

Builders,
As I arrived at the point where I may install the bubble doors, I have some questions:
Are your doors in the frame, or are they overlapping the frame?
At all three sides (the top is to be trimmed)?
Is it correct that the doors are not too flush with the door frame at the bottom?
I searched the forum, I would be very happy with any kind of detailed photos you have....
As is said more than often: it is more easy to trim too much than too little...


Te in advance,

[Dorsal]

Here is one in process shot I have.
http://www.teamkitfox.com/Forums/picture.php?albumid=202&pictureid=2427

[AirFox]

This is good timing. I just finished installing my bubble doors. This link has a pdf file that has very good directions for installing the doors.
http://www.teamkitfox.com/Forums/showthread.php?t=2860&highlight=bubble+door

My tool kit came with a 1/8 and 1/4 drill bit for the acrilic doors. In the directions you will need a 5/32 drill bit also. I couldn't find one last Sunday when I went to several places looking. I found on the internet that they suggested using a Uni-Bit for acrilic. I'll have to say that the Unibit worked great for me. You will also need a #12 bit to drill the holes in the door frame.

Good luck!

Scott

[jiott]

I had to trim some at the top to get the door centered up on the frame. Then all the sides were trimmed to fit within the fuselage frame lip.

Jim

[Esser]

For those who have used rivnuts, how did you back drill the acrylic? I'm assuming you didn't drill through the whole doorframe.

[Av8r3400]

Josh - What to you mean "back drill"?

I used RivNuts on mine.

[efwd]

Josh
you can buy ($6-7) at Aircraft Spruce a Strap Duplicator-bushing type. I have made a couple of these very easily. But, drill the frame and install your rivnut. Use the strap dublicator and drill the glass. To make it just use two strips of aluminum riveted together on one end. Drill a hole clean through both strips on the opposite end. place a machine screw the size of the rivnut through the one side, with the screw head sandwiched between the two sheets of aluminum.
Eddie

[jrevens]

You can also just locate the holes pretty accurately through the clear plastic, making a little mark with a fine point Sharpie. It doesn't have to be a close tolerance hole and will be oversize anyway.

[Cherrybark]

After mounting the glass with the hinge bolts and trimming to fit the door frame, I put the frame / glass on a worktable - glass up. Used a Sharpie to locate mounting holes around the frame and drilled through the plastic with a plastic bit, letting the bit ride on the frame to scratch a locating mark. Removed the glass, drilled larger holes in the frame and installed RivNuts. Laid the glass in place and started installing #10 pan heads (if I remember correctly) with nylon washers. There were a couple of holes in the plastic that needed to be enlarged and a couple of holes were filed into slightly oval shapes but the head of the screw covered the holes. Didn't want any pressure between a bolt and the plastic.

After sending a big crack across a bubble in a previous cutting mishap, I was leery of the Unibit. You'll find special plastic bits on eBay.

[Esser]

Josh
you can buy ($6-7) at Aircraft Spruce a Strap Duplicator-bushing type. I have made a couple of these very easily. But, drill the frame and install your rivnut. Use the strap dublicator and drill the glass. To make it just use two strips of aluminum riveted together on one end. Drill a hole clean through both strips on the opposite end. place a machine screw the size of the rivnut through the one side, with the screw head sandwiched between the two sheets of aluminum.
Eddie

Took me a second to visualize what you were describing but it makes sense. Thanks Eddie.


John, I think I may end up going your route or Carls since as you said, they will be oversized anyway if the tolerance is out slightly.

Carl, I do have acrylic bits that came with the kit so I will use those over the unibit.

[Esser]

Started trimming the doors and made the discovery that when I installed my hinges, I foolish forgot to leave room for the thickness of the bubble doors.

Should I slot the holes the hinges are in and move the hinge outward? Or should I cut the bubble doors around the hinge? I am leaning to slotting the holes are I am worried about cracking etc if I try to cut out the acrylic where the hinges are.

[efwd]

I believe you would not fix the problem by cutting out the Acrylic around the hinge. Doing so would still have the acrylic loaded up on either side of the hinge when you pull the door closed. Im guessing you have not yet put the foam seal on the acrylic at this stage as well. You need to account for that also. Your sure to crack the door with all those factors playing into it. If it were me, I would buy another length of hing. You would likely only need to cut the one half and pull the hinge wire out and put your new half in the old half's place. The screws are countersunk so if you slot them I can't imagine that the attempt at countersinking the new extended slot is going to be that clean. How can you keep the countersink bit tight into the end of the slot? Just things to consider.
That is if Im understanding your situation of course.

[Cherrybark]

Ah, the bubble doors. Easily the most nerve wracking part of the build so far.

Buying a new hinge is a good idea. I had a concern that the the existing holes in the fuselage tab might not happen to be located so the new hinge could be mounted outboard a bit. But if slotting the holes in the existing hinge will work, there should be room to drill new hinge holes clear of the hinge pin "bulge".

Nice solution if the hole spacing will work.

[Esser]

I would only be slotting the holes on the steel fuselage tabs. The hinges won't be modified they just have to be moved outboard

[jiott]

I would slot the holes in the fuselage tabs, then there would be no issues with the c'sunk holes in the hinges themselves. On final installation I would also put some Hysol in the unused end of the slots to kind of fill that in. Buying new hinge halves and redrilling them is also a good option. Also very good advice from efwd to remember to allow for the foam door seal, and I also believe there is a another thin rubber cushion between the hinge and the plexi.

[Cherrybark]

Would definitely favor slotting the fuselage tabs over messing with the acrylic. That $400+ piece of glass is very tender.

And, as Jim said, fill the gap with a bit of Hysol. A piece of blue tape on the bottom of the tab to keep things flush, touch up with a dot of paint if you want to get fancy.

[efwd]

I'm a bit more clear on the issue now. Slotting would work. I used Carl's technique on my door strut attach point at the panel. You can't tell unless I pointed it out.