Measuring Ovals

Depends on what you need to know. CMM is always good, but do you need location, or length, width, depth?

What do you mean by 'oval'? A rectangle with more-or-less radiused corners (like a running track)? An ellipse? A generalized oval (as per the Wikipedia entry)?

We make radius millwork and are having a lot of trouble making ellipse and oval trim that fits around the windows. I know that there are systems available toa ccuratly measure these and make templates so they fit perfectly, but most are very expensive and I was wondering if anybody had any suggestions on the best way to measure these so they are accurate.

An oval what?

Whoops... didn't see #3

Hi STICK

You can use a trammels to set out a perfect oval. It can be made from a piece of brandering with 3 x 4" nails. pieces of brandering can also serve as centre line guides.

Google for trammels.

How to fit a oval around a rectangular window using a trammels.

Because it bis possible to fir thousands of ovals you must specify one of the axis.

For example if you choose the minor axis to be x hit 2 nails in the brandering x/2 apart. Now put the drawing nail on the corner and the other nail on the horizontal centre line. the 3rd nail must then be inserted where it crosses the vertical centre line.

Then you are ready to "draw" your oval. (the 2 nails must always be on the respective centre lines)

Best of luck.

Use this link http://www.du.edu/~jcalvert/math/ellipse.htm

This is OK for a gen-u-ine ellipse, but STICK suggested 'ovals' as well in #3 (see my Wiki link in #2).

The Best Way = Digitize it into CAD and mill it on a CNC machine.

=========================================

The most efficient (cost effective) method for your application may require a different (rigged up) approach.

I spent my early years farming so I'm all for "keep it simple - and cheap" but if this is a matter of serious $$ then go high tech and make it happen.

Oval windows are usually accompanied by a template for making the cutout. You should be able to get a template from the window manufacturer for each type window and then produce a fixture from it. Ya think...

What about a thick piece of paper and a pencil. Trace the shape then cut it to make a template.

What do you mean by "measure"?

Are you looking for the area? If so, try a planimeter.

Sure, you can touch off edges with a CMM, but if you had a CMM you probably would not be asking the question.

Travis