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Does anyone know the best way to draw an Arch

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Forum topic by Budd posted 08-04-2010 03:15 AM 1476 views 0 times favorited 12 replies Add to Favorites Watch
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Budd

7 posts in 2400 days


08-04-2010 03:15 AM

I need to cut an decorative arch or curve in the support for a step stool; I guess they would be considered the rails in the project. I seem to remember one way of using string but I have not been able to make this work. Does anyone know the method or a better method?

Thank you
Bud

-- Bud Paddock


12 replies so far

View canadianchips's profile

canadianchips

2360 posts in 2464 days


#1 posted 08-04-2010 03:19 AM

A flat stick with a tiny nail in one end, drill a hole for your pencil in the other end,

-- "My mission in life - make everyone smile !"

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lew

11347 posts in 3222 days


#2 posted 08-04-2010 03:21 AM

I use a thin wooden strip with a string tied from one end to the other. As the string is pulled tighter, the strip bows. Then just use a pencil to draw along the strip. I know this “thingy” has a name but I’m not sure what it is!

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

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araldite

188 posts in 2870 days


#3 posted 08-04-2010 03:37 AM

I’ve tapped in three nails, two at the bottom where I want the arch to end, and one at the apex. Then I just wrap a flexible wooden or plastic strip or a long flexible metal ruler over the top nail and hook it under the bottom two to form the arch. This gives something that conforms to the exact piece you’re working with. You can add additional nails to change the shape until you get something you like. Then trace it out with a pencil so the nail holes are on the line and cut out.

-- Failure is the road to success if you learn to learn from your mistakes - Vince, Greenville, SC

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CharlieM1958

16244 posts in 3685 days


#4 posted 08-04-2010 04:44 AM

Ditto what araldite said.

-- Charlie M. "Woodworking - patience = firewood"

View mgb_2x's profile

mgb_2x

179 posts in 2536 days


#5 posted 08-04-2010 04:57 AM

The gateway arch in st louis is a inverted cantenary curve. As I recall the only way to get this shape is to suspend a steel chain between two points. Here is a link on making the shape. ?http://www.ehow.com/how_5024601_build-catenary-curve-arch.html?

-- "aim small miss small" m g breedlove

View BertFlores58's profile

BertFlores58

1684 posts in 2389 days


#6 posted 08-04-2010 06:27 AM

I think there is no room to find the center of the arc as it is now a step stool meaning irregular arc has to be done. You can use the process in making an ellipse. Connect both points where the arc should end – this become the major axis and the minor half axis will be set as you like depending on the string length and the two focal points which will be nailed in along the major axis. Note.. If the two focal points meet in the midpoint of the axis then it will create a circle.

-- Bert

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Budd

7 posts in 2400 days


#7 posted 08-05-2010 05:36 AM

Thank you all for all you information, this will help.

-- Bud Paddock

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Lucywu2012

18 posts in 2358 days


#8 posted 08-05-2010 09:23 AM

Even though I can’t help you, I still want that you can solve your problem soon!

-- Lucy, China, Bamboo Art Designer, http://www.chinese-bamboo.com

View swirt's profile

swirt

2118 posts in 2438 days


#9 posted 08-05-2010 05:37 PM

Another option is to draw it on the computer (be sure to include horizontal and vertical reference lines) . Print it out, then draw with a pencil over the printed curve. Turn the page over so the pencil covered side is against the wood, then trace over the arch again. The pencil will usually transfer to the wood.

-- Galootish log blog, http://www.timberframe-tools.com

View SnowyRiver's profile

SnowyRiver

51452 posts in 2947 days


#10 posted 08-05-2010 06:12 PM

I do it like araldite suggested.

-- Wayne - Plymouth MN

View Knothead62's profile

Knothead62

2581 posts in 2428 days


#11 posted 08-06-2010 12:31 AM

What lew described is a fairing stick.

View David Craig's profile

David Craig

2136 posts in 2575 days


#12 posted 08-06-2010 03:17 AM

Something you might want to look for in the future is a set of french curves. With a set of three, you can make a very large variety of shapes and sizes to plan out a figurative curve.

David

-- There is little that is simple when it comes to making a simple box.

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