Maths equation circle and stamps

[HondoMan]

Odd title. Odd indeed.

I must be getting old and my maths were a very long time ago.  Seems there is an equation to solve this wee riddle.

Let's say I have a stamp that is 0,8mm long.  I need a circle in which the stamp will fit nicely without a gap between the first and last.  In order to figure out possible diameters, what would the equation be?

I can't for the bloody life of me recall. 

Anyone?

Cheers and have a nice start to the coming week,

~ Hondo

 

[YinTx]

Sketches help me understand what you are trying to solve... wasn't always the best at word problems without a sketch...

YinTx

[Northmount]

You need to start with an approximate diameter that you would like to end up with.  Calculate the circumference = 3.14 x diameter.  Divide the circumference by your stamp length 0.8 mm. (pretty small stamp)  Round the number up or down to a whole number.  Use that as you new circumference.  Divide by 3.14 to get your new diameter.

Tom

[LatigoAmigo]

I'm feelin' ya. I love math and math problems, but over the years the ways these kinds of questions are answered has slipped away, so these days I let software do the work.

Adobe Illustrator allows one to create a "pattern brush," so I made a circle with a diameter measuring 8 mm (0.8 is very tiny... can do that too), and made a circle with 24 of them. Let me know and I'll make you a template for any size and number that you'd like. It is very easy to do.

Twenty-four 8mm Circles.pdf

[Nuttish]

Do I understand correctly that you want to know the diameter of a circle around which you want to distribute a given whole number of smaller circles (enclosing your stamp)?

[Outfitr]

I usually just fit the stamp to whatever circle. I make sure to stop far enough in advance of the end to trial fit the stamp to see if I fudge it tight or a little loose to make it fit. Usually unnoticeable. 

[Rockoboy]

4 hours ago, Outfitr said:

fudge it tight or a little loose to make it fit. Usually unnoticeable

This is what I do, usually for the last 4 - 6 impressions, depending on how long, and what shape the run is.

[HondoMan]

On 4/8/2018 at 10:44 PM, YinTx said:

 

 

On 4/9/2018 at 0:54 AM, Northmount said:

 

 

On 4/9/2018 at 7:23 AM, LatigoAmigo said:

 

 

On 4/9/2018 at 9:26 PM, Nuttish said:

 

 

On 4/12/2018 at 5:26 AM, Outfitr said:

 

 

On 4/12/2018 at 10:20 AM, Rockoboy said:

 

Apologies for the late response.... the responses are truly appreciated.

As an example, I want the stamp below to fit properly around a circle.  I have yet to make the circle on leather.  I know the stamp has a length of 13mm, and I would like to know what diameter or circumference would be feasible so the stamp fits properly.  Imagine one makes the second to last stamp and there is an 9mm or 10mm gap.  That last stamp won't fit.  

What mathematical equation would assist?

Cheers!

 

 

 

 

[Northmount]

@HondoMan You need to propose an approximate outside diameter of the stamped circle.  We have no idea of your application, so obviously can't provide a solution.  Use my info from above with your preferred diameter and stamp length.

Tom

[Retswerb]

@HondoMan, let’s try as @Northmount suggested with the circle from your image above.

I’m going to guess those grid squares are 0.5 cm (5mm) apart. If so, your circle is app. 73 mm diameter. So, 73*3.14=229.22 for your circle’s circumference as drawn. 

Now divide circumference by stamp size: 229.22/13=17.63 - so you’re halfway between 17 stamp impressions and 18. Pick which you prefer - we’ll say 18 here - and multiply that number by stamp size to get a circumference that will work. 18*13=234 .

Now take that circumference and divide by 3.14 to get your diameter: 234/3.14=74.52 . To set your compass you need the radius, so divide by 2: 74.52/2=37.26mm.

Does that make sense?