Needing a math formula

[Over-Head]

I rememebr back in school there was an equation which I can figure out how long the arc of a circle is from the 0-90-180-270 sections? c= (pie) x d
Is there a formula which you could work to deturmin how big an arc you need, or just work the same one backwards?
Math wasn't my strong point in school

Say I'm running a 2 ring medallion with an outer script.
Radius ring 1 = 18 inches
Radius ring 2 = 42 inches
Client would like me to run a script around the outer ring about 6 inches away from the second medallion.
each script section is a certian lenght, and I want even spacing between them.


C= pie x d
then just divide it would tell me how long each section is, will working it backwards do the same thing?
I'm figuring it will

I tried dumping Antifreeze on my loose leaf, then hanging it up to dry with nutt hooks....didn't help.

[Jenson71]

Originally Posted by Over-Head

I tried dumping Antifreeze on my loose leaf, then hanging it up to dry with nutt hooks....didn't help.

Did your loose leaf come from an AIDS tree?

[Crush]

[Over-Head]

Originally Posted by Jenson71

Did your loose leaf come from an AIDS tree?

couldn't tell ya. Normally I do a live mock up in 1/4 sections on site, I'm designing this one for a house 6500 miles away

[notorious]

Diameter x 3.14 / 4 = each 90 degree length.


If I read you question right, the diameter of the outside Medallion is 84 inches. 6 inches out from each side would equal 96 inches.


Diameter is 96. 96 x 3.14 = 301.44 for the circum.


Circum/4 = 75.36 inches per 90 degree section


If I read your question right, this is your answer.

[Extra Point]

Arc length of 90 degree swept angle=3.1416*d/4=.7854XD
Double the angle, double the arc length.
Is that about it?

[Over-Head]

Originally Posted by notorious

Diameter x 3.14 / 4 = each 90 degree length.


If I read you question right, the diameter of the outside Medallion is 84 inches. 6 inches out from each side would equal 96 inches.


Diameter is 96. 96 x 3.14 = 301.44 for the circum.


Circum/4 = 75.36 inches per 90 degree section


If I read your question right, this is your answer.

Yep.
ok, question,
if you work the equation backwards from the starting point of
I want to add multiple peices each X number of inches long,
with an equil spacing around the ring.
Can I take the length of the piece, plus the spacing, and create a ring that way as certian peices are different lengths.?
The 6 inch spacing from the outer ring was for the sake of a number, It might have to be 7 or 5. This is what i'm trying to figure out "on paper"

[notorious]

Originally Posted by Over-Head

Yep.
ok, question if you work the equation backwards from the starting point of
I want to add multiple peices each X number of inches long,
with an equil spacing around the ring.
Can I take the length of the piece, plus the spacing, and create a ring that way?
The 6 inch spacing from the outer ring was for the sake of a number, It might have to be 7 or 5. This is what i'm trying to figure out "on paper"

I am not the best at creating equations, just practical application.


I was the kid that the teacher didn't like because I could give her correct answers without using equations.

Practically speaking, I would figure your spacing between each ring and figure your equation mutiple times until you have the desired amount of rings.

[Over-Head]

Originally Posted by notorious

I am not the best at creating equations, just practical application.


I was the kid that the teacher didn't like because I could give her correct answers without using equations.

Practically speaking, I would figure your spacing between each ring and figure your equation mutiple times until you have the desired amount of rings.

Thanks.
Math was never my strong point, and truth be known if it wernt for a certian photo the appeared from a teachers staff party my band played at in a bar one christmass, i'd never have gotten the 3 points I needed for a math credit to graduate
Hell I spent more time in the hall than I ever did in math class, and from Grade 8 summer school, right to grade 12 I never did pass a year in math.
Sure hating myself fot it 25 years later let me tell ya!!

[notorious]

Sorry, I just read your edited post.

It would take me awhile to think a linear equation to figure that out.


How many rings do you want?

What is the desired outside diameter?

What is the desired inside diameter?

[cdcox]

Not sure if I understand the question but here goes.

If the circle has a diameter of d the circumference of the circle is

C = pi * D

Now unroll the circle so it lays out flat.

The circumference must equal the sum of the pieces plus the spacings with everything laid out flat and straight. If your pieces are already curved, you could measure their flat length with a flexible tape or something.

[Over-Head]

Originally Posted by notorious

Sorry, I just read your edited post.

It would take me awhile to think a linear equation to figure that out.


How many rings do you want?

What is the desired outside diameter?

What is the desired inside diameter?

Yeah, sorry about that. I realised I had forgotten "part" of the question when I posted it...(hey Raiders fans aint too bright ya know !!)

This currant project will ues the exact dimensiuons of a past one. (room size just worked out that way.)

More of a "if i'm in this situation, how do you figure it out".

So a linear equation is what i'm looking for...got it.
If I had even know what to call it, I could have started googling.

[notorious]

Originally Posted by Over-Head

Yeah, sorry about that. I realised I had forgotten "part" of the question when I posted it...(hey Raiders fans aint too bright ya know !!)

This currant project will ues the exact dimensiuons of a past one. (room size just worked out that way.)

More of a "if i'm in this situation, how do you figure it out".

So a linear equation is what i'm looking for...got it.
If I had even know what to call it, I could have started googling.

When I put in a wood floor that has some wild designs, it's off to the drafting board


If I were doing circles in ring radiating from a point, I put a screw in the center, measure and cut the string to a desired length and a attach a pencil. You can tweek the length by screwing/unscrewing the line around either the screw or pencil (I prefer the line around the screw to just be looped, that way it doesn't have a very small change in length as it wraps around).

The more rings you add, just cut a new line that much longer and remark the line.

I hope this helps. Sometimes I run into a wild shape that will screw with me a little bit, and I work on something else while I think about it. Next thing you know it becomes very simple.

[Over-Head]

Originally Posted by cdcox

Not sure if I understand the question but here goes.

If the circle has a diameter of d the circumference of the circle is

C = pi * D

Now unroll the circle so it lays out flat.

The circumference must equal the sum of the pieces plus the spacings with everything laid out flat and straight. If your pieces are already curved, you could measure their flat length with a flexible tape or something.

Pieces are stright, by placement, and design I create the illusion, of them arcing

Thanks
Never hurts to double check with folks who actually know math, then guess at it.

[Over-Head]

Originally Posted by notorious

When I put in a wood floor that has some wild designs, it's off to the drafting board


If I were doing circles in ring radiating from a point, I put a screw in the center, measure and cut the string to a desired length and a attach a pencil. You can tweek the length by screwing/unscrewing the line around either the screw or pencil (I prefer the line around the screw to just be looped, that way it doesn't have a very small change in length as it wraps around).

The more rings you add, just cut a new line that much longer and remark the line.

I hope this helps. Sometimes I run into a wild shape that will screw with me a little bit, and I work on something else while I think about it. Next thing you know it becomes very simple.

Basically the same spinning medallions on the ceiling, you just need a fixed center point that everything runs off.

Most the stuff I do, is done on site, and I have extensive notes on past ceilings i've done for re-creation.
While great for former projects, as I expand my line, all my pieces to teh puzzle change as well.
I have a friend of mine getting me a copy of a computer program he uses for designing graphics which suposewdly will do it all for me.
But I always like having a pen and paper back up just in case.