There were a ton of bifold manufacturers at Osh and I thought they all looked great and well built. Really not that expensive when you think about the cost of building anything and running a business these days.

As I get older I try to prioritise where I spend my time. Every minute that I just spent on a rental Reno was painful as I really wanted to be working on the project PA18.

Good point about the limit switch, I’ve been meaning to add for a while. Overwind is a real risk.

daedaluscan wrote:
Good point about the limit switch, I’ve been meaning to add for a while. Overwind is a real risk.

I assume “overwind” pertains to cables? The big issue with bi-folds is opening beyond a safe angle of collapse. If the open door doesn’t create a structural triangle the bending moment at the base of the door becomes huge as the weight of the full door tries to twist itself off.

IMO this is the main benefit of limit switches (in the context of bifold.) Obviously not the only benefit.

Imagine a big guy crawls into your airplane while in the hanger. He rolls aileron in to the stop, but the switch in his brain didn’t keep him from continuing further.

Zzz wrote:

daedaluscan wrote:
Good point about the limit switch, I’ve been meaning to add for a while. Overwind is a real risk.

I assume “overwind” pertains to cables? The big issue with bi-folds is opening beyond a safe angle of collapse. If the open door doesn’t create a structural triangle the bending moment at the base of the door becomes huge as the weight of the full door tries to twist itself off.

This is the main reason for limit switches.

Yes, I guess technically overwind in a mine lift is when the cage gets to the top and you keep pulling, cable then detaches. I’m afraid of pulling beyond the design height so that the two panels fall down with the hinge point low. This was why I made the top panel shorter so that the lower panel can never actually meet it, but I have no desire to see if that works in practice. I want a limit switch to stop it where I normally do.

My hangar used to be surrounded by trees on two sides, but they just clear cut to the East of me so I am much less comfortable leaving the door open as I get a lot more wind.

Another error I made was putting the clear plastic on three sides of the hangar and not on the door which faces SW so I often open the door to let light in.

daedaluscan wrote: This was why I made the top panel shorter so that the lower panel can never actually meet it, but I have no desire to see if that works in practice.

That's a pretty clever solution to that. Now I need to measure mine to see if the top panel is shorter.

My R&M Steel hanger has the bifold Schweiss, 208vac motor and auto latch. Opening is 40’ by 12’6”. Works great. If I build another hanger…maybe at K Beach Medows Airpark in Kenai Ak. Jury is still out on that one. I’ll build my door… buy the steel building.
With your relatively low header I’d think a single piece hydraulic door would be better. Two double acting cylinders probably 4” bore, the math may turn out needing less. The pump can be a fancy setup or a manual valve, and a hydraulic pump motor combination with the correct gpm to raise the door at an acceptable rate. You’d have to build a box truss across the width of the door on the exterior side of the header to hang/hinge the door. Probably 3/16” wall 4” square tubing. Hopefully that man door at a right angle to the hanger door swings in. You’d need to build a diagonal brace system at both ends to support the load trying to pull the top of the door away from the hanger…. The door I’d build using the same material as the box truss. At the bottom of the door would be another box truss at a right angle to the door to prevent sagging as the door opens. That said, I’ve done this sort of thing professionally, concept to cad to fabrication, although not a single hanger door.

That's a great perspective! It's important to find a balance between DIY projects and enjoying life. I've also been a DIY enthusiast for years, but I've started prioritizing my time differently as I get older. Sometimes, it's worth hiring help to focus on the things that bring more joy and relaxation.

If considering at all a HydroSwing type single piece door as a do-it-yourself project, no need to re-invent the wheel! Just copy a factory built one, and they take no where near 4" hydraulic cylinders. Well maybe, there's a huge single piece door in Alpine WY that is at least 80' span, it may! I was flush with cash after selling my old property and then moving onto new, and in a hurry,when I bought two of them, one for my shop, one for the hangar, after building 3 of various types in the past that worked, were cheap, but always a bit of a hassle, didn't seal good, etc., but at least got whatever I was flying out of the weather. My heated shop door faces the storm winds, the stronger the wind the more the door is pushed against the weatherstripping, I like that. Plus I have 2 5'x5' south facing windows in it, for winter sun and the killer view. Similar with the hangar door, BUT everytime I use them, I think "I coulda built this." ESPECIALLY if I had one to eyeball/copy, commonly available components, and I'm a competent welder and steel fabber. I love the awning effect when they are open also. Just be sure to have the bulding front strong enough to take the stress, which applies to most big doors.