Real size patterns

[Mike Hide]

I am in the middle of making a walnut corner cabinet. There is some dimensioned sketches provided and a bill of materials . I t is a beautiful cabinet adn the author has attempted to give every dimension to ensure a perfect copy can be made .

This is a difficult task, resulting in the inevitable mistakes in some of the dimensions ,as much as 5" inches in some cases .

So here is a suggestion that I use to precheck the dimensions provided, given that the sketches are to scale .

Take the sketch and scan into your imaging program . I usually scan it in greyscale and then enhance the scan by increasing the contrast .

Now crop the area you are interested in [say a door assy], crop it exactly to one of the given dimensions , then size the scanned image to the exact size of the dimension cropped to for printing .

The result should be a to scale print that can at least be used to double check the written plan dimensions ...

-- mike hide

[JackD]

There are two dangers in this approach.

First, the sketch might not be to scale. People make mistakes in drawings frequently. This is the reason that architectural plans frequently call out "DO NOT SCALE" and builders will use the printed dimensions to actually build from. Perhaps in the CAD era this is diminishing as the dimensions can be automatically generated, but it is still a concern.

The second danger is that sometimes printers do not print exactly to scale. Some are a bit longer in one dimension than the other. I'd imagine that a scanner could have a similar problem.

The best way to do this is to add up all the dimensions and check the math.

-Jack

[Mike Hide]

This is exactly what should be done in practice , add up the dimensions ,check the math ,and them build it .

Trouble is when you do this and the thing turns out wrong anyway ,regardless how many times you do the math and check the dimensions. this is especially true whe simply milling materials from a bill of material .In my case I found door stiles widths incorrect and door panels too long [5"] .

When all said and done the method I describe at least provides a simple cross check and an invaluable reference to any complex freehand profiles ....mjh