Discussion in 'Workshop Tips and Secrets / Tools' started by bmcj, Aug 30, 2015.
One way to prevent going overcenter is to make the lower panel taller than the upper panel.
It might not look like you'd prefer, but I think the best way to maintain the ability to use the space up to the peak and not overstress the existing structure is with a bifold (horizontally hinged) rectangular door with its own frame. Anything else is going to be complex, fussy, and expensive.
Another "tinfoil hat" idea:
How about a roll down curtain door that stows into a pocket in the floor? The center retract wire would need to be removed and stowed to move planes in or out but that shouldn't be much of a problem. The local FBO has a flexible, insulated, roll up door that has been in service for at least a decade that is proving to be durable and efficient.
I agree. I seriously doubt that the existing building was designed with a bi-fold door in mind. It's highly unlikely that you'd be able to build it light enough to lower the lateral loads to an acceptable level. I still have my doubts that fiberglass would be lighter than steel to start with.
The split, non-rectangular arrangement (yellow doors) is probably going to require a column in the middle. Otherwise, I don't see how you will support those inside corners. If you expect the door panels to be rigid enough to come up straight I think you will be disappointed. And you would then be introducing all kinds of twisting loads into the door panels and a building that, almost certainly, will not be able to handle it.
If that was my building, I think I'd close in the gable at the top of the door and do either a hydraulic swing out type door or a regular bi-fold door in the remaining (now rectangular) opening, depending on the height of the opening that I could live with.
Rain, water, mud, oil, grit--that pocket and the curtain that drops into it will not be a pretty sight for long. And a pocket wide enough to hold the curtain would need it's own strong lid to allow planes to roll over it. But the curtain idea could be a good one. It could be suspended from a horizontal light rail held up by posts at the ends that go as high as the peak. Chains/cables periodically down to the fabric curtain, with guy wires from the center top of the rail down along the eaves to keep the curtain held against the structure.
And we have the beginning of the development of an "out of the box" idea..........................
A hair-brained idea has been presented, and some obvious potential problems identified. Are those problems insurmountable? Are there other problems yet to be identified?
A 16' tall insulated curtain 1" wide would roll up into a 16" diameter roll. Make it 18" for a loose roll and clearance. Put that in a 18" wide by 20" deep" trough with a sloped bottom and a trash pump at one end. 3/8" thick steel plate or 1" thick deck grate (either steel or plastic) is plenty strong enough for a 1 ton truck to cross. Leave a 2 inch gap for the curtain to pass through, which would be closed by the upper support when the door is lowered leaving no tripping hazard. The deck plate could be removed as needed to clean out what didn't get sucked out with the trash pump.
How to construct the curtain so it can take the wind loads and not make a bunch of noise?
Is there there a place to discharge the trash pump water?
What happens if the curtain gets water logged? Is it self draining?
How to keep tension of the curtain during retraction so the roll is tight?
Is the HOA going to be agreeable to this idea?
Diagonal hinges and split vertically in the middle.
Alternative, beams vertical on the sides ending in a quarter arc where they are hinged. That would make it a normal one piece door, save the curved beam ends.
Maybe the same roller curtain idea, but keep the roll at the top? Avoids need to dig, deal with debris, need for a strong cover, etc. Gravity would help provide tension during roll-up, and most of the water on a wet curtain would drain during retraction (but not all of it. A squeegee at the top would help, or consider a "dimpled" membrane surface to let a wet curtain continue to drain to the bottom of the roll and out when rolled up, and for long-term air drying).
Any non-rigid door does reduce the chance of damage if blown off. And the lighter the door, the less structure is needed to support it (though structure needed to handle wind loading won't change).
If you really want an out-of-the-box idea, how about concrete doors? The Lightweight Concrete Company
Yes, I know it would still be heavy, but concrete that will (if I am reading their specs correctly) float on water! Make the door a quarter inch thick and reinforce it with pultruded rods instead of rebar. :gig:
By the way, I was able to get a ROUGH measurement...
- The opening between the brick pillars is 40.5 feet;
- The corner height is 8.4 feet (101 inches);
- The apex height is 11.7 feet (140 inches).
I suspect my Starduster Too upper wing is close to 8 feet high (long gear for my 8 foot propeller).
Making 8 pound/ft^3 cement (not concrete which has aggregate in it) is actually pretty easy. When I worked in a cement lab we mixed all kinds of things in to make it light ..... and cheap. Something as simple as a bit of detergent in the mix could get you there. Phenolic micro balloons are also used. Some of these mixes even had <3000 psi comprehensive strength!
There is also such a thing as fiberglass rebar.
So maybe it's not so far fetched an idea as you may think?
It all depends what you want--a construction experiment or a hangar door.
Easiest way to make this happen is a split door. Sliders that come up the top of the wall height and a swing up upper door section that carries the upper slider tracks. Structural loads for the upper section would not be nearly the problem as with a complete bi fold door. We actually have a system sort of like this at work. The main door sections are powered sliders and the center upper door is a 10' wide powered rollup door. It lets us put an xC-135 sized aircraft in a hangar that was not designed for an a/c that tall.
Here's a pic of one of the doors I built for my buddy's T hanger. Six doors in all. Caveat is that we didn't need to comply with any particular building codes, so it's not engineered. We went with the when in doubt build it stout method, and it seems to be holding up ok. Rams where from a surplus store and quite cheep. A little shorter than Ideal, but they work fine. There is a truss of 2x2 steel tubing at the bottom, and the hinges are attached at the top of the beam for full clearance. I know this isn't the rigth type of building for comparison, but it is an example of a relatively affordable single piece hanger door built by an amateur. It's about 41'W x 14'H
My wife watches HGTV where the show buyers 3 property's and they always buy one. Silly!!!! There was a house for like 2 million. It had a hanger attached to the house. It was maybe 100 yards to a lake. There was a landscaped ditch leading to the lake with rail tracks. In the hanger the floor matched the bottom of the airplane so they could load the airplane with out climbing on the floats. The door worked with remote control and it folded up and out at the same time. I guess any thing is possible.
Danny at Phillipburg airport had just bought a 42 door. It comes just the frame he tells me and you put the skin and insulation on yourself to suite you. Door wasn't that expensive. It will be here and installed in Dec. Its for a new hanger he is rebuilding.
Do you know the name of the company he bought the door from?
And this is what it's come down to?:gig:
(We tried Mr. Cotter.)
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