Molded Highlander windshields

[AV8R Paul]

Are you still fabricating the SuperSTOL & Highlander Molded Windshields

[AV8R Paul]

I am contemplating building a SuperSTOL, and I would prefer a pre-molded Windshield.

[stede52]

Paul, I'm still making the windshields in clear. Just let me know when you will need one.

Steve

[messenger]

steve I posted this question on the pop pop rivets heading....
Steve, I am replacing the lexan and you give instructions for the installation of the lexan on the doors and windows , and you say to do the install with the window and door frames on the plane in the closed or locked position, elaborate on that part a little for me. Is this to keep the frame in the correct form for the lexan? so drill the holes in the lexan, use clecos to hold in place, install everything on the plane then remove the tape strip and screw or pop rivet in place. thanks for your time, I have already installed one of your windshields and it is great.

[kenryan]

Steve, have you evaluated the crash worthiness of your windshield, versus the lexan that comes with the kit?

[stede52]

Ken,
I have not done any kind of testing in that area for two reasons, 1: I'm no structural engineer and 2: all certified aircraft use acrylic for windshields. The structural properties of polycarbonate versus acrylic are quit different and what I know about the two is that if each were the same thickness the polycarbonate (lexan) is a tougher material. The acrylic is a harder material which allows you to polish it and remove scratches, however, being harder also makes it more brittle and will break using less force then polycarbonate. I've had pilots tell me that they will never put polycarbonate windows in an airplane because if they were in an accident and needed to punch out a window or windshield to escape the aircraft its nearly impossible to do so with polycarbonate, where acrylic they could. I can't imagine a 1/16" polycarbonate material under load (which compromises its structural integrity) like it is on the Highlander being that much stronger then an 1/8" molded windshield which is not under load and therefore will maintain its structural integrity. The gradual bend of the 1/16" poly ok on the Highlander however at the upper corners of the windshield it is under extreme load and is bend far beyond what the specs say it should be for that thickness of material. That is one reason cracking occurs down the windshield at those areas along with the constant vibrating and flexing of that thinner material in flight.

[kenryan]

Thanks Steve. Good explanation.

[danerazz]

Steve,

My installation is a little custom due to a vastly different boot cowl/glare shield setup. I am thinking of using rubber well nuts for windshield installation at the boot cowl junction, so only rubber would be contacting the acrylic. Is there any reason this would be a bad idea? I am looking at a 8-32 with a 5/16 hole in the windshield.

[SheepdogRD]

A well nut is a rivet nut with a flexible coating, right? So you'd crimp the rivet nut into the windshield, and fasten through the boot cowl into the nut? Seems like compressing the rivet nuts would put stress into the windshield.

Check the high bond tape recommendation from Steve here: http://www.wingsforum.com/viewtopic.php?f=218&t=23713&hilit=high+bond#p47861

[danerazz]

No, it is a threaded insert bonded into a rubber "T". You drill a hole big enough for the soft rubber to fit into, then use it like a blind nut. As you tighten the screw it pulls the threaded insert forward causing the rubber to expand. You control how much it expands by how tight you make the screw. This is how most motorcycle windshields are installed. It is a soft rubber fastener

http://www.stanleyengineeredfastening.com/brands/pop/well-nut-threaded-inserts

[danerazz]

Like this, but the well nut would be through the windshield and the screw would be through the fairing, unlike the first image.

[SheepdogRD]

That seems like a pretty good application -- no matter how the windshield moves, it never contacts metal.

[stede52]

Steve,

My installation is a little custom due to a vastly different boot cowl/glare shield setup. I am thinking of using rubber well nuts for windshield installation at the boot cowl junction, so only rubber would be contacting the acrylic. Is there any reason this would be a bad idea? I am looking at a 8-32 with a 5/16 hole in the windshield.

Dane,
Looks like a nice way to install. Anytime you can keep the screw treads away from the acrylic its all good.

[Tralika]

Anyone know a source for buying the Wellnuts? I just finished my electrical system and panel. Windshield is next.

[kenryan]

Looks like Lowe's has them in a variety of sizes:
https://www.lowes.com/pd/Hillman-1-4-in-20-x-3-4-in-Rubber-Standard-SAE-Well-Nut/3012494?cm_mmc=SCE_PLA-_-ToolsAndHardware-_-Fasteners-_-3012494:Hillman&CAWELAID=&kpid=3012494&CAGPSPN=pla&store_code=289&k_clickID=90a112a8-37ef-48fa-9da7-757750790376&gclid=CjwKEAjwgZrJBRDS38GH1Kv_vGYSJAD8j4DfoAbu6eZg_K0c2Ybq3umknltg_nyWMZHTIWA_wcrYHBoCI63w_wcB