How to scale full size from a picture???

[Dennis Collins]

How would you a create a full scale pattern from a picture of a piece you want to build. For example if I had a jpg picture of chippendale mirror that I would like to make but not sure how to scale it to full size. Is there a tool to do this....? The overall dimension is 37" h x 20" w.

What do you do?

32954

[Jeffrey Makiel]

Some CAD programs allow you to insert photos (or more properly called 'raster images'). Then you can use the 'scale' tool to scale the picture to its full size using one reference dimension, like the mirror's height. The only problem is, how do you plot something that big? You would need a 24" or 36" wide designjet plotter, or a regular desktop printer with a lot of cellophane tape! Although some Staples stores and Triangle Repro stores have drawing sheet size plotters.
-Jeff

[Chris Pasko]

I believe there was an article in Fine Wood Working a while back that showed how to do exactly what you need with paper and a pencil. I will try to find the issue and post which it is.

[Dick Parr]

For myself I try to find something in the picture to scale off of, like tile or an object with a common size. If there isn't anything then I just make it to fit the space I have for it.

On a workbench I lay out 4 pieces of wood to the size I want the piece to be and then draw inside the wood, or just draw lines and stay inside the lines. If you don't have drafting supplies, use can's and bottles to draw curves to the size you want.

It sounds hard but it's pretty easy after a few tries. If I can do it, anyone can.:D

Good luck

[Tom Sontag]

Fortunately you have selected what is basically a two dimensional project to scale from a flat two dimensional picture. This is much easier to explain than scaling three dimensional perspective, which is what the FWW article explained so well.

Just blow up the picture on a copier as large as you can while keeping some focus. Measure a known distance using a very fine scaled ruler (eg. millimeters). Now convert every other dimension you measure using the proportion you just calculated. It would make sense to sketch the detailed curvy outlines full scale and so on. I use a fine point mechanical pencil and on something like this mirror might even draw a grid over the picture to blow up details that cannot really be measured very well. Patience, persistence and a careful eye is what you need. Good luck.

[Barry O'Mahony]

Some CAD programs allow you to insert photos (or more properly called 'raster images'). Then you can use the 'scale' tool to scale the picture to its full size using one reference dimension, like the mirror's height. The only problem is, how do you plot something that big? You would need a 24" or 36" wide designjet plotter, or a regular desktop printer with a lot of cellophane tape! Although some Staples stores and Triangle Repro stores have drawing sheet size plotters.
-JeffVisio will print a large page out on multiple sheets, that you can then tape together. That's what I usually do. Or you can take it to Kinko's and print it out on one of their large-format printers.

For something like this I'd paste the picture into Visio, and enlarge it to life-size. Then I'd trace over the outline with line segments and curves, and delete the picture, leaving just the line drawing for the template.

[Greg Narozniak]

Long time ago in High School I was in a art class dropping off parts of a WW project the shop class was doing and I saw several people had done it like this.

Take the original picture and use a scale ruler (1/8" = 1" something like that) and draw a grid with light pencil on the original and then the same larger scale on a blank sheet.

Then you transfer the contents of each box from the orginal to the large one. This of course was before Computers so there must be an easier way nowadays :)

[Ken Fitzgerald]

I'm in the process of trying to design a small shaker style candle table for my wife and a friend as we speak. IMHO, the problem arises with the fact that you really need to know 1 dimension's absolute size to properly scale something. If you know 1 absolute dimension you can scale something. For example, I have a photograph of a shaker candle table. If I know that the normal shaker candle table is say, 27 inches tall, then I can scale that photo so the table is 27 inches tall. If I keep the aspect ratio the same while scaling, the width should be properly scaled too. Now, since I'm talking about turning the center spindle for the table.....I've got a lot of measuring and drawing to do!

[Julio Navarro]

http://www.ies.co.jp/math/java/geo/panta/panta.html

A pantograph can help you redraw the image to a larger size by tracing the out line.

I ve used this nifty instrument before, many many many moons before, usually after I had used my slide rule.

Trial and error will yield the result you may want.

Kids will love it too.

[Rick Thom]

Denis, several approaches. To get to original size, you've got to have 1 actual dimension. That can be measured from the original or even estimated from some other known length shown in the picture ie a 'given' in math terms. From that you can create a scale and all other dimensions are referenced to that given. Pictures aren't always precise in that some camera lenses create illusions or distortions such as depth or wide angle which can throw off the scale. I think if you aren't working from measured or provided dimensions, it's wise to sketch out and sometimes even create full size plan/model and give it the saliva test.... does it look right and in prospective. That is the ultimate test for me.
To get detail right you can scan the picture and up-size to get the scale of cuts right, and also reference to known points. You can plot that on quad graph paper to exact scale and make a template.
FYI I made a mirror similar to that which you have used as an example. The original of that was measured to be exactly 31" high and I computed the width (to be 18 1/4"), and all other dimensions accordingly. The actual glass is 16 x 10 1/4" making it a somewhat diminutive package overall. Of course there are as many variations as there are craftsmen for any of these pieces, but mine is the twin to the photo which is a circa 1780-1810 fret-sawn rococo-style Chippendale period looking glass made of curled maple.

[Jim Becker]

Jim Tolpin's Measure Twice, Cut Once has a section of taking off from photos, I believe.

[Gary Breckenridge]

:cool: I would Xerox it onto graph paper.:D

[Mike Williams]

I believe there was an article in Fine Wood Working a while back that showed how to do exactly what you need with paper and a pencil. I will try to find the issue and post which it is.

Chris - I hope you don't mind me jumping in. The article was in FWW 170,page 59 (May / June 2004).

[Julio Navarro]

Photo copy it and use the pantograph to up scale it to your size

[Dennis Collins]

The overall size is 37" h x 20" w. Does this help?

[Julio Navarro]

Denis, do you know where the dimesions are to and from? There is alot of scroll work, can you guess at where the dimensions start. I can copy this picture into autocad and plot you a full size print to use as a template. Not sure how sharp it would be after a large enlargement, pixels tend to enlarge as well when you blow up a picture.

[Steve Schoene]

Jim Tolpin's Measure Twice, Cut Once has a section of taking off from photos, I believe.

So does Jeffrey Greene's American Furniture in the Eighteenth Century.

[Jeff DeVore]

I would scan it into corel draw and then trace it with the bezier tool. Then delete the image and scale it to size. Draw several different color indexing lines horizontal and vertical and then print it out to several sheets and tape it together. Hope this helps, Jeff.

[John Lucas]

http://www.woodworking.org/photo/albums/userpics/10750/Mirror-r.JPG

I dont know if this helps, but I did two different Chippendale mirrors and I worked from a little picture in the Williamsburg catalog. I did this one in 93 and the earlier one in the 60's. Both time I used the same method. I took the small caatalog shot and copied them enlarging them until the dimensions were close to the product size as listed in the catalog.
By the time you get there, the image is really fuzzy but there is enough detail to draw an acetate drawing that I could make real size masonite templates from. I wanted these so that I could make more than one copy and the masonite would hold up - and it has.
Chippendale covers quite a range of mirror outlines. If you google you will get some great ideas and photos to "borrow" Here is one that comes up that I like and seems close toyours:
http://www.laurelmeadow.com/images/Chippendale%20mirror%20large.jpg
There is enough detail to give you guidance. Good luck with yourproject. By the way, Norm did one years ago and you can get full size plans of his.

[tod evans]

http://www.ies.co.jp/math/java/geo/panta/panta.html

A pantograph can help you redraw the image to a larger size by tracing the out line.

I ve used this nifty instrument before, many many many moons before, usually after I had used my slide rule.

Trial and error will yield the result you may want.

Kids will love it too.

i too use a pantograph to enlarge or shrink stuff, it`s faster for me `cause i`m a computer idiot......02 tod

[Rob Will]

Art supply stores such as Dick Blick sell projectors that can do this. I would project 1/4 of the design onto a poster board and cut it out. Invert it for the other side. Art projectors range from $30 to $100 (?) depending on quality.

Another method would be to use an electronic projector. Load your image into PowerPoint and draw your pattern.

Rob

[Ken Fitzgerald]

Dennis..........I'm in the process of making a shaker style table for the LOML. I found several pictures of one that my wifel liked. I use a cheap 2-D cad program called KeyCad. This morning I was able to take the picture and change if from a .JPG file to a .bmp file and import it into the cad program. I know that most tables of this style have a table top that is 17-18 inches in diameter. In the program I turned on the grid system and adjusted the grid line spacing until 18 of them were displayed across the table top. I kept the vertical and horizontal grid lines spacing equal. Now if I print the photo with the grid lines applied, this will give me an appropriate sizing for measuring the dimensions at different points along the turned spindle.

Something to consider.

Good luck!