# Measuring a curve



## Dak (Mar 9, 2011)

Im going to start a project with templates provided but 
I have to tape the pages together. How do i measure the length of a curve. Im guessing the overall length
Disregarding the curve. Thanks for your help.


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## woodnthings (Jan 24, 2009)

*there are 2 methods*

Mathematically, if it's a regular or consistent curve or arc.
Manually using a string or flexible tape on the template.
If you can tape a string to the curve along it's length then mark the start and finish, then stretch it out straight and measure it with a tape or scale. 
Which would be best? :blink: bill
I suk at math, so I know which way I'd do it...... :thumbdown:


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## ponch37300 (Feb 27, 2008)

As woodnthings mentioned a string makes quick work of measuring a curve. I've also seen some flexable rubber like "things" for marking curves that would work.


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## DaveTTC (May 25, 2012)

I imagine the length of a curve is measured as illustrated

Dave The Turning Cowboy


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## cabinetman (Jul 5, 2007)

Depending on how accurate the measurement has to be, I may use something that has no stretch to it, like a wire, which can take and hold a curve. Bailing wire is cheap and works pretty good.









 





 
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## WillemJM (Aug 18, 2011)

If her dimensions were 36 x 26 x 36, I would measure by hand, otherwise the easiest is to do the math.:shifty:

The angle in radians x the radius of the circle is the length of the arc.

Or, if you are working in degrees:

Angle in degrees x π/180 x radius of the circle.


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## Dak (Mar 9, 2011)

I think the first illustration by Dave is the way these drawings are designed. The problem is when i tape the template together the measurements just don't match to the cut list. If i do make it match then I'm altering the curve.


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## woodnthings (Jan 24, 2009)

*I think we are not getting it.... maybe just me?*



Dak said:


> I think the first illustration by Dave is the way these drawings are designed. The problem is when i tape the template together the measurements just don't match to the cut list. If i do make it match then I'm altering the curve.


Are you trying to determine what radius the curve is ...
Or do you want to know the length of the curve? 
And if so for what reason? I can't imagine why that dimension would be necessary in making something...it's more of a theoretical mathematical inquiry, than a practical one in my opinion.

To determine the radius of the curve on a plan you'll need a pencil compass to strike some arcs and determine lengths equal distance from the curve.  bill


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## Dak (Mar 9, 2011)

I printed out a template on 8 x 11 paper and have to tape them together to get a template. When I do this the over lenght doesn't match the cut list.


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## Dak (Mar 9, 2011)

Sorry. So when I do adjust it for length I'm worried I'll distort the curve.


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## woodnthings (Jan 24, 2009)

*What project, what curve, what cut list?*



Dak said:


> I printed out a template on 8 x 11 paper and have to tape them together to get a template. When I do this the over lenght doesn't match the cut list.





Dak said:


> Sorry. So when I do adjust it for length I'm worried I'll distort the curve.





Dak said:


> Im going to start a project with templates provided but
> I have to tape the pages together. How do i measure the length of a curve. Im guessing the overall length
> Disregarding the curve. Thanks for your help.


This is all too theoretical to offer any specific advice.
Then you have an issue of the printout possibly being out of whack or distorted. Are these down loaded plans or actual dimension drawings?
You would expect a curved piece to fit within a part on a cut list. The piece must be cut from a longer piece with waste, therefore the cut listed piece must allow for the waste.....

What is the piece and why is this not a matter of simply laying the taped template to fit an overall dimension?

Can you post a photo of what you are trying to do and a scan of the curve you are referring to? 

What does the length of the curve have to do with anything?

I've never seen a set of plans that specified the length of a curve and I've drawn many plans myself.

Ya Got Me here Bud......:blink:


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## jigs-n-fixtures (Apr 28, 2012)

Dak said:


> I printed out a template on 8 x 11 paper and have to tape them together to get a template. When I do this the over lenght doesn't match the cut list.


Can you have Kinkos print the pls on one larger sheet without breaking it onto two sheets.

Sent from my iPhone using Wood Forum


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## cabinetman (Jul 5, 2007)

Dak said:


> I printed out a template on 8 x 11 paper and have to tape them together to get a template. When I do this the over lenght doesn't match the cut list.





Dak said:


> Sorry. So when I do adjust it for length I'm worried I'll distort the curve.


Formulas for figuring the lengths of curves are IMO useless. What works on paper, doesn't always work in the third dimension. I've done quite a bit of curved woodworking, and have had plans supplied by designers and architects. Usually in those situations, I make my own shop drawings. 

I would do that with supplied plans that suggest or supplies a cut list. With those, you have a provided template, and a cutlist that is supposed to represent the sizes to make it all come out right. How the changing the length may distort the curve can be checked by what is important. Is the pattern what you need to wind up with? If so, the lengths of the cut pieces should match what the pattern shows.

I make full size drawings on the brown or white rolled wrapping paper. It's cheap and sold in most stationery sections of food stores and drug stores...it's readily available. I think the standard size widths on the roll is 30" and 36" x many feet long. I draw out to scale full size (1:1) what I want to make. I cut my pieces and shape them as necessary, and then fit them to the drawing. 

Doing it that way you can plan sizes and lengths, and figure out any joinery needed. That's just the way I do it.










 







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## tito5 (Apr 5, 2011)

I agree with woodnthings......sounds like your print outs are messed up. where did you print them from? I know one place I go to block posters.com will let you select how many sheets you want the image on, and what type of paper and orientation you want. I know I was confused the first time I ran it, because the image didnt' match up at all. figures out I had selected 11x14 and landscape, but printed 8 x 11 and portrait ......so long story short make sure your print settings are correct.


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## Dak (Mar 9, 2011)

This is a free plan from popular woodworking. The titanic deck chair. I can't rely on the template because that will screw everything up.


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## woodnthings (Jan 24, 2009)

*no answers*

I'm done here. :thumbdown:


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## cabinetman (Jul 5, 2007)

Dak said:


> This is a free plan from popular woodworking. The titanic deck chair. I can't rely on the template because that will screw everything up.


Are you sure you are understanding the plan correctly? It seems that you have received some good suggestions in this thread.









 







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## Dak (Mar 9, 2011)

Nevermind


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## KevinGe (Mar 16, 2012)

ponch37300 said:


> As woodnthings mentioned a string makes quick work of measuring a curve. I've also seen some flexable rubber like "things" for marking curves that would work.


Lol...ya those flexible rubber like "things" work great on curves not to mention they are stiff enough to transfer the radius to a template. I use one whenever I work with any kind of curved profile, and I have no idea what it is called but your description works great.
Cheers


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## WillemJM (Aug 18, 2011)

KevinGe said:


> Lol...ya those flexible rubber like "things" work great on curves not to mention they are stiff enough to transfer the radius to a template. I use one whenever I work with any kind of curved profile, and I have no idea what it is called but your description works great.
> Cheers


Flexible curve ruler.


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