How do I find this arch!?

[TheSnowman]

I am working on a sign for a building that was just renovated. They built this arch area for the sign into the front, and I'm just wanting to make sure that I'm thinking right so I don't have to redo this and be out lots of time and money.

I took the length of the two sides to the bottom of the arches, then I took the middle of the arch, and used the pen tool to connect the dots. Is it that simple? In my head there should be more to it, but I don't know what it would be. I'm going back to all of this geometry stuff in my head, but just not 100% the right way to confirm my arch is right. Can anyone help me to make sure, judging by these measurement?

 

[300mphGraphics]

I would check a few other places on the arch for measurements, not just the ends and center to be sure. If the install isn't too far away, I'd probably print out a black and white laser on bond, trim, and check fit. Could also under size it and finish with trim moulding.

 

[AnotherSignManiac]

I would cut a template out of vinyl to double check your measurements and arch

 

[letterman7]

Yep, a trip out to confirm the dimensions would definitely be in order. It isn't that large - take some banner paper out and tape it over the opening and make a rubbing of the inside of the trim.

 

[dsmskyline]

Id ask the owner to see if they have a blueprint of when the arch was built. The other option is getting ahold of the contractor that built it and see what they say.

Somewhere the information is there about the angle.

 

[oldgoatroper]

When these arches are built by carpenters, the radius will not always be precisely constant. It's always best to take a hunk of cardboard or a roll of paper, tape it up in the actual arch and trim to fit.

This is the only way you will know for sure....

You could also measure the height of the arch from the base of the opening every 8" inches or so. That would get you close.

 

[TheSnowman]

Banner PAPER? I don't have that. Give me a link as to what you are talking about. I just want to hit this on the first shot. I can't imagine us having a decent enough day coming up to get back up there and get paper to hold still. I'm trying to come up with some way to work with what's there from the front...but I suppose that doesn't exist.

 

[TheSnowman]

The worst part is the giant awning they built under it...you have to get out a giant extension ladder, and it's a pain to get to and it's awkward.

 

[oldgoatroper]

It doesn't have to be banner paper -- it can be any kind of paper or cardboard. Two inch masking tape holds it in place as you trim the paper to fit the curve.

 

[SignManiac]

when these arches are built by carpenters, the radius will not always be precisely constant. It's always best to take a hunk of cardboard or a roll of paper, tape it up in the actual arch and trim to fit.

This is the only way you will know for sure....

You could also measure the height of the arch from the base of the opening every 8" inches or so. That would get you close.

+100

 

[thinksigns]

I drew a couple of shapes and aligned them. Should get you close enough.

 

[DigitalSolutions]

Id find it by measuring from the center of the flat long edge to the top center of the arc. Then in the design program transfer that point to a ruled intersection, measured from the bottom of the shape. convert the shape to a poly-arc and adjust the top arc to come to the ruled intersection. you just better make damn sure that your center measurement is spot on

 

[MikeD]

you could get the engineer's drawing and hope that the carpenter didn't have to deviate at all, but the safest way would be to make a cardboard template as suggested above.
If it is too difficult to access, maybe you could photograph it (head on; at it's elevation) and find a common element like a brick face to get the scale.
Good Luck!

 

[oldgoatroper]

All of these calculations are worthless if the person building the arch just eyeballed it.

The absolute best, no-worries and only way to fit an existing arch is to go and get a template of it.

 

[TheSnowman]

My installer is going to build a cardboard template of it tomorrow. Thanks for reassuring me of what my big concern was. Hopefully we'll be good to go.

 

[qmr55]

You could also measure the height of the arch from the base of the opening every 8" inches or so. That would get you close.

This here.

 

[Billct2]

Yep, template's the only way to be sure.

 

[Hicalibersigns]

Uh, just throwing this out there and waiting to get stomped, but isn't your photo a template? Size it up to actual size in AI, trace it, turn it into a CutContour path and let 'er rip, so to speak. Am I crazy, or wouldn't this be close enough?

 

[oldgoatroper]

The photo is a reliable template only if you know that it was taken perpendicular to the surface of the arched area both vertically and horizontally.

Yes, it looks close but I would not rely on it to be accurate enough unless I knew I had taken the pic properly.

 

[TheSnowman]

The picture was taken on the street, and the sign is basically second story, so that's no good. I figured that'd give me trouble.