×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Formula for datum points

Formula for datum points

Formula for datum points

(OP)
Hi All,

I am trying to place a bunch of battery strings (circles) inside of a tube . Using the machinery's handbook there is different configurations for packing circles inside of circles.  Has anyone ever made a formula for creating datum points or pattern table to assemble parts to pack circles inside of a circle?

Tofflemire

RE: Formula for datum points

Tofflemire,

I don't know if I well understood your problem, but if you need a patern of tangent circles on a curve here is a solution:

Supposing you have a tube having an internal radius "Ri". You need to place N small wires inside (on a single circle). This circle will have a radius "R". The wires will have a radius "r"

Now, what you need in R or r, supposing you'll know how many wires you want to place or knwoing the wires radius, you want to know how many wires you can place.

Let's take the first one: You know "Ri", and N.

alpha = 360/N

r = R*sin(alpha/2)
R + r = Ri

Now you have:

R + R*sin(alpha/2) = Ri
R(1+sin(alpha/2)) = Ri

R = Ri/(1+sin(alpha/2))

And of course will result the wire radius:

r = Ri*sin(alpha/2)/(1+sin(alpha/2))

I hope this is what you want.

-Hora
 

RE: Formula for datum points

(OP)
Hi Hora,

Thanks for your formula.  When I used the words "battery string", I meant 12 d-cell batteries wired together in series to make a string, and then I place another string tangent and wire it to the other string in parallel etc...  I need to place 24 of these strings tangent each other in 1 of the 4 the configuration shown in the machinery's handbook under the section Number of circles in a circle.  I would to have a formula, pattern table or even a relation so I can change a couple of variables to get my strings locations quick and easily.

Sorry for the confusion.

Tofflemire
i Hora,

Thanks for your formula.  When I used the words "battery string", I meant 12 batterys wired together in series to make a string, then I place another string tangent and wire it to the other string in paralle ect...  I need to place 24 of these strings tangent each other in 1 of the 4 the configuration shown in the machinery's handbook under the section Number of circles in a circle.  I would to have a formula, pattern table or even a relation so I can change a couple of varibles to get my strings location.

Sorry for the confusion.

Tofflemire

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources