Redsail X700 Rotary Attachment Math ?

[Deane Donaghy]

This has probably been asked a heap of times before, but I need a little guidance with my new Redsail Rotary Attachment (Lathe Chuck Style).
I can setup the mechanics no problem, but the Chinglish instructions baffle me, plus I am dumb as dog sh..

So the instructions read, Quote: " C=2 π R (Pie I think ?) - "when R changes, step length from the follow changes, R is the semidiameter of the object you will engrave on and the unit is millimeter"
Can some one of greater knowledge translate that to plain English that I might understand, please.

[Glen Monaghan]

When you are engraving a cylindrical object with a rotary device, the length of the object normally is the (maximum) height of your graphic and C is normally the maximum width. You can easily measure end to end length of the glass, vase, bottle or whatever round object you have with a ruler or tape measure, but you also need to know the distance around the outside of the object. That distance is referred to as the circumference, abbreviated as C.

While you can measure C directly with something like a string, you then have to straighten out the string and measure it with a ruler or the like. Or, calculate C from a number that you can easily measure with a ruler, caliper, or other linear measuring device.

Circumference or C can be calculated by multiplying 2 times Pi (3.14159) times the round object's radius, which is abbreviated as R (aka "semidiameter"). Unless you have specs that tells you the radius, it's usually easier to measure and use the diameter, D, which is twice the radius: C=Pi*D. Doesn't really matter what units you use for R or D, because the result C will be in the same units as R or D. So use R or D in mm and C will be in mm, use R or D in inches and C will be in inches.

-Glen

[Real Mercier]

This is the equation for the circumference of a circle.

C = Circumference (Length around the piece)
R = Radius of the piece
Pi = 3.1416

You can use the equation C= Pi D where D is the diameter.

The circumference is used as the page height in your graphics program and usually represents one full revolution of the rotary device.

Hope this helps.

Real Mercier

[Deane Donaghy]

Thank you guys.
Maths was never one of my strong subjects when I was in school 40 years ago.
That is roughly what I suspected, but the Chinglish instruction threw me a bit.
Now for a test run