Windshield curvature?

[TXFB.INS]

Have an out of town truck that needs vinyl applied to the windshield. as usual getting the truck prior to install for measurements is NOT possible

calculating the amount of the curve is the easy part, radius = (m² + ¼c²)/2m

What I can't seem to find is the curvature of the windshield so I can go ahead and get it made

the truck is GMC 2004, any one know what it is or where it can be found?

 

[Mosh]

Can you cut between the letters while installing, to align with the top of the windshield? I do it that way sometimes.

 

[J Hill Designs]

usually its really close, if not perfectly, straight

 

[TXFB.INS]

it may come down to cutting during install, was hoping to save some time and have it pre-done

will keep pecking online and see if I can get the curvature

 

[Biker Scout]

The vinyl will curve in a slight frown, to conform to a compound curve. Most people get this wrong and make it a smile.

 

[bob]

The easiest way is to tape a piece of paper to the windshield, trace the edges with a sharpie, then lay the tracing flat on a table and either take its picture and import it or determine its geometry with a few straight lines and a ruler. All you need is the top edge and a bit of the sides.

This is by far the simplest way to render a relatively mild three dimensional object into two-space.

 

[phototec]

Being from Texas (me to), you know almost everyone here drives a truck, and the used car lots are FULL of them, just look in your local paper for someone selling a 1999-2007 GMC or Chevy, or 2000-20006 Suburban (all use the same windshield), stop by on your way into the shop and ask them if you can make a paper pattern of the top of the windshield. And do as Bob suggest.

OR: Go by your local auto glass shop, and they should have a windshield in stock, and you could trace the pattern from there.

I have done it for different vehicles and then hang the pattern on the wall and take a digital photo of the pattern (straight-on) with a yard stick in the photo, import into Photoshop and enlarge the pattern to full scale using the yardstick dimensions as reference, it works great!

I back off and use a short telephoto lens to eliminate any distortion when taking the image of the pattern.

http://www.lmctruck.com/features/ce/ce9wa.htm

 

[airborneassault]

I have a trick I think I recall reading on here. Measure down on both sides of the windshield (any distance just make sure it's the same on both sides).

Let's say 6", make a mark on both sides and stretch a string taught along those marks. Now find center of the windshield and measure down to your string, for grins let's say it reads 4.5".

Now in your design program you can account for the bottom outer edges to be 1.5" (6-4.5) lower than the center making the "frown" arc that follows the windshield.

 

[ChaseO]

I have a trick I think I recall reading on here. Measure down on both sides of the windshield (any distance just make sure it's the same on both sides).

Let's say 6", make a mark on both sides and stretch a string taught along those marks. Now find center of the windshield and measure down to your string, for grins let's say it reads 4.5".

Now in your design program you can account for the bottom outer edges to be 1.5" (6-4.5) lower than the center making the "frown" arc that follows the windshield.

Excellent. Basically the same thing I do.

 

[Biker Scout]

Oh yeah, you only have to map out or measure half the windshield too. Since it better be symmetrical

 

[bob]

I have a trick I think I recall reading on here. Measure down on both sides of the windshield (any distance just make sure it's the same on both sides).

Let's say 6", make a mark on both sides and stretch a string taught along those marks. Now find center of the windshield and measure down to your string, for grins let's say it reads 4.5".

Now in your design program you can account for the bottom outer edges to be 1.5" (6-4.5) lower than the center making the "frown" arc that follows the windshield.

This assumes that the curve is an arc, a section of a circle. More often than not it is not an arc, just a curve. There's an infinite number of curves that are not arcs.

 

[ChaseO]

That is true too, but if you're doing a sunstrip decal that's not the full width of the glass, only you and God will know if it's not perfect. Another thing to consider is if there is any window tint on the sunstrip. I've been known to take a measurement from that to figure out the curve too. If that doesn't work, I usually do what Mosh suggested.

 

[neil_se]

We just lay a long ruler across the top of the windscreen, butt it up against the rubber at the centre, and measure the gap left at the sides. In Illustrator draw a box with those dimensions eg, 40mm x 1000mm, type the text so it sits on the top of the box, then arc until it touches the bottom of the box.

Doesn't help it you don't have the vehicle to measure though.

 

[Marshall Signs]

Try this - Take two tape measures, extend one tape out across the windshield and flip in over so the bottom is up. This will allow it to flex across the glass easier. Line up the tape with the top of the corners of the windshield, same place on each side. Usually were the rubber meets the trim piece. Then, with a little practice, use the other tape to measure the distance from the top edge of the windshield tape to the same spot the corners are lined up with, were the rubber meets the trim. On average its around 1 1/4", but can vary between 3/4" and an 1 1/2", but usually not more than that. Since your tape measure is already across the windshield might as well measure it for length. Use the center to subtract your radius measurement in to a frown.

I trust this helps, it works for this Redneck, thanks.

 

[Hero Signs]

Usually a 25 to 30 degree text on a curve will make a straight linenon most cars. Flexi rocks