Hangar door suggestions

[ShawnR]

Hi all
It has been a busy summer and not much metal related going on so I have not been around much. But a project has come up (still only fringing on metal related) that I was hoping to find input for. With the myriad amount of diversified talent on this forum, I think I have a good chance of finding the input I need.

I bought a hangar (very ugly hangar) this summer, to hold the airplane I hope to have shortly. The hangar is a bit of a project. Currently, sides have sunk a bit and the front doors consist of 4 doors. They are each 2x2 framing. The two main doors are about 16 feet wide by 8 feet high, vertical bifold, lifted by a hand winch each. The two end doors are 4 feet wide by 8 feet high, on hinges. They are covered in paper-machine screening (aka "the wire" where the pulp is dumped onto to form the sheet).

Common general aviation hangar doors come in a few different designs. Vertical lift bifolds (of 2 panels) (VLB), bypass sliding (of 4 panels) (BPS), horizontal folding bifolds (of 4 panels) (HFB)

Each has their pros and cons. The VLB are the nicest I think. They are not subjected to winds as much as the horizontally opening ones. The hardware gets a little complicated. Finding a motor that would be adequate and on 12 or 24 VDC is a little difficult. See examples here

BPS require the barn door hangar rail to extend past the ends of the hangar. I am not a fan.

The HFB are probably the easiest but are subject to wind loads when open (although I am not a fan on flying on super windy days anyways. )

I figured that there seem to be a lot of farmers here that have dealt with large doors on barns and tractor sheds.

What have you built? What do you like?

The Schweiss design uses several lift straps of webbing, wrapping on pulleys on one long shaft driven by a strong motor. I do not have access to power there except via a possible solar system of some sort. I am wondering about using this design but lifting the door with a chain pulley and maybe a counter weight instead of a motor..? I have some concerns about the strength of the header over the door to take the weight of the new doors. The hangar is old but I noted a nailing plate on the inside, indicating to me it may have been engineered. Considering the apparent age of this hangar, the sag for a 40 foot span is not bad so it must have some integrity. I think I will be adding another layer of half inch plywood, screwed into the truss to reinforce the existing structure. The rest of the building is stick framed with rough lumber. It all needs TLC but looks ok, .... I had to jack up the East wall to replace a rotten bottom plate and that whole wall needs to be level a bit more.

If you had time to explore the Schweiss system, think this can be converted to a manual lift? I was thinking about putting the pulleys on the top of the door and the straps affixed to the bottom of the door. Typically, the motor driven shaft is at the bottom of the door so would not be conducive to a hand pulley system.

What to use for a shaft? My garage door at home is a 1" diameter steel pipe, looks kinda light but lifts a 14' wide wooden door ok. Torsion springs are attached to it. I may be able to get this in longer lengths or use electrical conduit?

So, that is the convoluted story. I need/want better looking and functioning doors 40 feet wide by 8 feet high.

Any input for me?

Thanks all.

Cheers,

 

[Darren]

My 12x12 comercial overhead doors have a 1" keyed solid shaft with torsion springs. I can lift them by hand easily. The 40' shaft could be made of separate shafts with couplers. I know where there may be a bunch of them. I know a few installers in our area.

The anchor bracket for the springs needs a very solid mount. You will need several along the length.

Or, cables and counterweights?

 

[ShawnR]

I am thinking that 1" solid is overkill, even if it is a good deal. Just too heavy given the door structure and header, but I was thinking 1" schedule 40. I have a few pillow block bearings but they would need a machined surface so black pipe might not be good. As I type, I thought of maybe turn a nice connector and use it at the pillow blocks, say 6" long. Mmmmm...

 

[Darren]

The problem with deviating from the norm is the pulleys and all the other hardware would need to be modified to suit.

 

[historicalarms]

google "farm shop doors" and Ill bet you will get some very good suggestions. Ive seen some bigger than what you specify that are a single fold winch lift that if I were building a big shop I'd sure be copying .

 

[YotaBota]

What about this for a concept? Have the doors slide around to the outside of the hanger using pins into the floor to lock the doors when closed.

 

[YYCHM]

Tell us about this airplane you are about to acquire.....

 

[Susquatch]

As a farmer and a machine shop guy, maybe I can help too.

No matter how good your current structure is, it can always be improved and braced to take whatever span load you need. It's not if, it's just how. So just set this issue aside until you decide on the door parameters and then design the frame structure to accommodate it.

The sliding barn doors on roller tracks work fantastic but they require a long side wall or those roller wings you say that you detest. If you have a wide wall on just one side, you could have shorter doors on one side and long ones on the other.

FWIW, you can put those doors up in layers either inside or outside. I've personally seen 4 layers (eight sliding doors).



Also, you can put track troughs on the floor to cut down the hanging weight issue, but winter snow and ice become a challenge.

Most of the multi layer systems I've seen open the inner most doors first on a long track. Each successive door has a sealing and connecting plate on the outside edge to seal and hold the door beneath. But I have also seen a few that were reversed. This arrangement gets very heavy to push as the doors accumulate. So good rollers and a good install are imperative. You sure as heck don't want the center sagging because you end up pushing the doors uphill!

Most of the tracks I've seen are extendable. And some already come as short sections of track that couple together.

Edit - scratch this whole next discussion. No way to support the track on the ceiling and still get a cable in. But I'm leaving it here in case it spawns another idea from others. And provide a laugh....

I don't know what the maximum sectional door width is. I have two 16w x 14h insulated sectionals with two large coil springs on solid one inch bars that can easily be lifted by hand. Mine have electric lifts but you need 120 for that. I would not bother with batteries. Just use the a geared chain system and be done with it.

Sectional doors like mine are available in 20ft widths. So my thoughts are to tie two 20s together with plate or extra long hinge pins to join them (basically turning them into 40ft sectionals) and use a double cable lift at the center behind the plates or the hinge pins, as well as a cord operated latch (or something) at the top center and a center latch at the floor to keep the wind from buckling them when they are closed.

I think the biggest problem would be the weight of the doors when open. To address this, I would maintain track wheels at the center but fabricate a trough funnel at the top to capture the wheels as the doors go up. You could use deep roller standoffs from top to bottom at the center to stop the door from hitting the roller track and then lift the center track a bit to keep the doors sitting flat.

That would be one very wide (40 ft) sectional door that you might not be able to use in the wind, but you probably don't fly on windy days anyway.

Edit 2 - leave the following part in. It still applies.

All in all, I favour the layered doors and a wench like @Brent H has to open and close them......

 

[ShawnR]

Tell us about this airplane you are about to acquire.....

Van's RV-4 But it is a bit of a fixer upper. Being a homebuilt, I can work on it, and am planning on pulling the wings off for the winter and bringing it home here to my shop for some improvements. Thanks for asking.

@YotaBota That looks interesting but those adjacent walls are 12 feet long and the doors each side will be 20'

@Susquatch One hangar at the airfield has a ground ie floor track. I could not imagine that working for long with frost heaves, etc. Thanks for the other input.

@historicalarms I will spend time tonight with google. I have done a bit already but mostly hangar door related.

Thanks all

 

[DPittman]

I have a 40ft vlb door (can't think of the manufacturer right now but it will come) . I too didn't have power at my hanger so I ended up using a generator and am very happy with my setup. Although I do wish the door had a a manual lift option. The door is great but I did have it lift of the track once when lifting it in a horrible wind one day but has never been a problem again.

Edit. I remember the brand of door I have....Diamond Doors (Canadian made).
The other nice thing about vlb doors is you get a great seal along the door that can sometimes be hard with hanging doors on rails.

 

[YotaBota]

That looks interesting but those adjacent walls are 12 feet long and the doors each side will be 20'

Just thinking about it, any reason the doors couldn't go past the 12' on the outside? Most T hangers are usually 24' deep overall.
The RV4 - 0-320 powered?

 

[Susquatch]

That looks interesting but those adjacent walls are 12 feet long and the doors each side will be 20'

40 ft = 2 twenty ft doors
Or 4 ten foot doors.

If you have 12 ft on each side, it is almost a no brainer to have 4 ten foot interlocking doors on two barn door rails. Most barn doors are more than that so it ought to be easy to push/pull 10 ft doors.

You can make them out of plywood and 2x4s which would be quite cost effective. Or aluminium prefab doors which would be light but more costly.

Doesn't get easier than plywood and 2x4s.

 

[Former Member]

When I was in University I was involved in a design competition between several Universities to design a 12m x 4m door mechanism for the roof sections for the Skydome (Rogers Centre now) with a 300year wind load and 150year snow load, power operation and manual operation if required. Also remember the mechanism needed to self lock and unlock in operation.

Mine won, whatever you make follow one simple principle K.I.S.S. (for those that don't know Keep it simple stupid!) Power required to lift and close is proportional to the leverage involved.

Looking at your structure, you header is on the light (undersized) side for the opening. Address this before proceeding. Roof on the plane....bad.

Second, without a complete rebuild, you are limited to header size to maintain opening size, so, what ever you do for doors and mechanism keep it as light as possible. Vertical rise vinyl cloth doors with post support at door jambs removes header loading and greatly simplifies to mechanism, no torison bars needed just balance springs/wts in support columns.

 

[DPittman]

So I ain't no expert but... one of the really nice features of vlb doors like the Diamond doors is that they really don't rely on your buildings header for strength as they have a built in frame that can be attached to almost any sort of wall/opening. At least that's how I see and understand them.

 

[trials20]

When I purchased my hanger it didn't have doors or walls, just a steel post and beam designed by a fab shop who's owner also had a plane. During the door phase, I was serious on a vertical hydraulic or bi-fold swing style of door as the header was strong enough to handle the loads but I didn't have power supply to run pumps or winches.
So it was a horizontal bi-fold setup using 2"x2"x.062" HSS framing and steel siding (very light), bullet hinges welded on the vertical posts and barn door tracking hanging from the header truss, no wheels. Door is 40' x 12'.
Your hanger looks a little light in structure and would require a upgrade before hanging anything from the roof support, looks like 2' stud centres with no diagonal bracing.
I vote for HFB.

 

[ShawnR]

Great input! Thanks

@Degen why do you say the header looks light? That is kind of my biggest concern but wondering how you got there. It is a 40 foot wide truss structure that looks like it was made by a truss company. The inside is mostly open but the outside is weak 1/2" plywood. I planned on scabbing on another layer of 1/2" plywood on the outside with screws. The truss components are mostly 2x6 from what I can see. It is a little covered on the inside ie a 12" ish plywood spanning the top and bottom, left to right. I will look for a photo.

But, are you saying a 4' high truss is not enough to span 40'? Would adding the 1/2" sheathing be enough to strengthen it? It has been standing like that for quite a while with minimal sag (although, some sag, I think). I am actually surprised but attribute it to,... of all the things the builder did,... at least it looks like he went with an engineered truss. Maybe I am wrong, I assume that because I saw a nailing plate like used in truss manufacturers. You can buy them at home hardware but I don't think many home hobbyists use them. Could be wrong.

So far, the plan is to add 1/2" sheathing to the truss structure on the front, spanning the width. Screwed through to truss components.

Making new doors with 2x4 verticals and a diagonal braced frame with 2x2's, then sheathed with 3/8" plywood ( compromise between weight of 1/2" and flimsiness of 1/4".

Make hinges cause I don't want to pay $20/hinge for 16 hinges and hey, need to add some metal working to the project. I did a calculation on the door weight and it came in around 150 lbs each (rounding up, adding paint, estimating, etc). On a barn door website (I forget where but they sold big hinges) I found an interesting point raised about moment calculations. We use these in flying for weight and balance but never thought if it for hinges. So 10 foot doors mean 1500 lbs on the hinges, but then, we will have 4, 2 per side, but then, the top track will support some weight, but then, there are 2 doors on the main hinges, ......

Geez, some people would just build something and deal with the outcome! Fun to learn a bit. I think the horizontal bifolds with big hinges and a top track will be ok....I hope....

Thanks for the input!

Cheers,

 

[Tecnico]

So I ain't no expert but... one of the really nice features of vlb doors like the Diamond doors is that they really don't rely on your buildings header for strength as they have a built in frame that can be attached to almost any sort of wall/opening. At least that's how I see and understand them.

@ShawnR glad you mentioned airplanes, it seems like there's a higher than normal corrlation between home machinists & flyers. The homebuilt category lends itself well to forming the link but maybe I should think about a separate thread in the Off Topic channel to get into that. Related: Part of my motivation to get my mill was to use it on an airplane project.

OK, hanger doors:

@DPittman raised a very interesting point for @ShawnR 's hanger or any hanger that may not be structurally well suited to hanging a relatively heavy door off of. There's a good example where we keep our family wings (C-152), an owner bought one of these economy tent style dome buildings offshore and had to come up with a working door.

He brewed up a VLB that used a robust steel frame that carried all the door loads into its ground mounting points independent from the tent. I think he used a generator to raise it.

As long as you close any gap between the door support frame and the hanger itself then you have a nice door and a secure/weather tight hanger.

While we're talking about door systems I think there's one more that hasn't been mentioned, a simple, full width, full height panel, hinged from the top, that in the example I saw, was raised by hydraulic cylinders at each end driven off of a hydraulic power pack. The power pack could be 12V like any mobile/vehicle mounted HPU. That door would be huge (40 x 10 or 12) and could possibly be counterbalanced by a (heavy?) weight(s) or some other Rube Goldberg contraption. The one I saw was commercial & fabbed from steel tubing with typical industrial building siding in steel (aluminum?) and was probably not excessively heavy. In that case it was run off of ........ a generator.

Anyhow, I will follow this thread and see what more I can learn about doors & hangers since I'm hoping at some point to add that to the to do list.

D

 

[ShawnR]

Attached is the photo of the inside of the door truss. I never really looked at it up close, like the photo shows. Kind of a surprise when I viewed it on the laptop. Water damage on the front sheating so it will be good to replace that/add to it. The structure looks more like 2x4 than 2x6.

Just wanted to add the photo...

The photos might be deceiving too. It is a T hangar so the max span of the roof supports is 12 feet. Where the back section opens into, there is a beam across it, and then another 12 feet to the back wall.

 

[DPittman]

@ShawnR glad you mentioned airplanes, it seems like there's a higher than normal corrlation between home machinists & flyers. The homebuilt category lends itself well to forming the link but maybe I should think about a separate thread in the Off Topic channel to get into that. Related: Part of my motivation to get my mill was to use it on an airplane project.

OK, hanger doors:

@DPittman raised a very interesting point for @ShawnR 's hanger or any hanger that may not be structurally well suited to hanging a relatively heavy door off of. There's a good example where we keep our family wings (C-152), an owner bought one of these economy tent style dome buildings offshore and had to come up with a working door.

He brewed up a VLB that used a robust steel frame that carried all the door loads into its ground mounting points independent from the tent. I think he used a generator to raise it.

As long as you close any gap between the door support frame and the hanger itself then you have a nice door and a secure/weather tight hanger.

While we're talking about door systems I think there's one more that hasn't been mentioned, a simple, full width, full height panel, hinged from the top, that in the example I saw, was raised by hydraulic cylinders at each end driven off of a hydraulic power pack. The power pack could be 12V like any mobile/vehicle mounted HPU. That door would be huge (40 x 10 or 12) and could possibly be counterbalanced by a (heavy?) weight(s) or some other Rube Goldberg contraption. The one I saw was commercial & fabbed from steel tubing with typical industrial building siding steel (aluminum?) siding and was probably not excessively heavy. In that case it was run off of ........ a generator.

Anyhow, I will follow this thread and see what more I can learn about doors & hangers since I'm hoping at some point to add that to the to do list.

D

One thing I think should be designed into any large overhead (as opposed to horizontally sliding) door is a brake system in case the lifting mechanism fails. My electrically operated vlb door has a brake in case power fails. I'm not sure how one would go about a brake system with a hydraulic system if a hose busted, maybe a flow control device? I imagine the commercially made hydraulic lift systems have something but I do not know what that is.

 

[Tecnico]

@Degen why do you say the header looks light? That is kind of my biggest concern but wondering how you got there. It is a 40 foot wide truss structure that looks like it was made by a truss company.

Please take my comments as not entirely analytical but indicative without hitting the (code) books. Here is one example of something to compare to without doing any math.

At our flying club they have some Tee hangers in a continuous building and when they had a structural engineer look at it for insurance purposes they wound up replacing the engineered (wooden) truss over the (sliding) doors with I think a 22 inch steel I-beam.

At first I thought it looked excessive but I was assured that when you drill down into the building codes (legally not binding on an airport but your insurer may insist anyway) the strength is needed for things like snow load and maximum deflection. The company that made your truss may be able to give you a load rating/application sheet that would give some useful data too.

In the end, you pays yer money & takes yer chances but your desire to learn a bit is a good way to stack the deck in your favor.

I'm sure there will be lots of help coming from the group, lots of varied experience to draw from.

D