windshield height

[chrisyk]

I have been trying to establish the height of the windshield. Th drawing gives a radius of the windshield bow, and gives rough dimensions of the polycarbonate. I emailed Kerry at Sonex and he said just install the bow as per plans. I have seen too many Sonexes with a dolphin nose, caused by the windshield being too low relative to the canopy. I would really like to avoid that look. Can anybody tell me what the measurement is on your non dolphin nosed Sonex, from the top of the glareshield to the underside of the bow? The bow is set at a 60 deg. angle, but a square measurement from the top of the glare shield to the bow should work.

Thanks in advance

Chris

[MichaelFarley56]

I just ran a straight edge across my upper longerons where the bow goes through them, and measuring straight up in the center puts the bow just under 17" above the longerons. Probably around 16.75" or so.

I think you'll be able to make it look pretty good regardless once you fit the canopy. Once you start trimming, you'll be able to make it work.

Also, I tried to follow the plans as much as possible and that measurement is how it ended up. Be careful and take your time! I rushed through mine and never have been happy with the final fit. Good luck!

[kmacht]

Forget about measurements for the height. To avoid the bottle nose problem you just make the back of the windshield as high as possible and then raise the bow to meet it. To install the windshield put it on as it comes from sonex and trim the sides so that the front edge fits nicely over the upper cowling strap. You trim the sides of the windshield tapered from back to front in order to get the front lower. The piece you cut off should be triangular shaped Do not trim anything off the back side and taper the cut towards the front. Once the front fits nicely you install the bow, raise it up until it meets the windshield and then drill it to the fuselage. You should have to cut about 1 inch off each end of the bow to get it to fit right

Keith
#554U

[chrisyk]

Thanks guys.
I have exactly 17 inches to the bow and when I installed the lexan I left it full width at the bow and had to trim about 1/2" off both sides at the nose. This changes the angle of the factory cut curve in the lexan at the bow which means you need to trim a bit off the lower aft corners. This in turn shortens the windshield and I had to buy another piece of lexan and start over. Another thing that made me wonder about what the correct height is the bow strap. The factory supplied strap is about 3/8" short on both sides. I'll live with it.

Chris
Sonex #1226

[rizzz]

Time to bump this topic again...
I'm about to make my windshield bow and install the windshield.
Here and on the yahoo groups most people say you need to try and install the windshield so that the aft side is as high as the lexan piece from Sonex allows it to be, only trim towards the forward side.
My only concern with this is, is there enough material on the canopy to match this height?

[tonyr]

Hi Michael,

Yes the canopy should be no problem, if I recall correctly I think I had 40-50mm of canopy skirt to trim off along each bottom edge. This was after setting the windshield at the maximimum height allowed by the material. I shimmed it up 3mm at the rear using strips of lexan cutoff just to gain a wee bit more. i.e. the lexan sits a little above the longeron at the canopy end but is flush at the firewall end. Aslo had to watch that the attaching screws hole to edge clearance was ok.
Also I didnt drill the canopy bow ends until I had finished trimming the windshield and had max height, just held them with clamps

Cheers
Tony

PS dont do what I did and blindly trim off the front according to someone elses website i.e. 1/2".. that was an expensive mistake LOL

[Fastcapy]

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[MichaelFarley56]

For what it's worth Michael, I only trimmed the front edges of my windshield a little and didn't reduce any along the back edges. I didn't want the "bottlenose" look and I believe it worked out.

Even if you set the windshield at maximum height, you'll have plenty of extra material on the canopy. Good luck; the windshield is pretty easy, but the canopy is a real PITA. Go slow and keep it as warm as possible!

[fastj22]

If you are worried you won't have enough canopy material, just clamp the uncut windshield to the fuselage, then drape the uncut canopy over the edge. You will see there's plenty of canopy to trim at max windshield height.

[daleandee]

Please keep in mind that when you get to the canopy part to use some painter's tape or heavy paper to protect the windshield and turtledeck from being scratched as you put the canopy on and off quite a number of times doing the fit up process. Some have done the canopy by themselves but a a steady handed friend is a real blessing.

Dale
N319WF