+ Reply to Thread
Results 1 to 11 of 11

How to calculate the diameter of a sprial.

  1. #1
    Registered User
    Join Date
    03-14-2012
    Location
    Belgium
    MS-Off Ver
    Excel 2010
    Posts
    15

    Question How to calculate the diameter of a sprial.

    I know, it's a weird title, but I cannot explain any better ; here's what I'm looking for.

    I have flexible plates with specific dimensions

    They need to be rolled up into a spiral and packed in a box.
    And I need to figure out how many rolls fit into that box.

    The dimensions are
    * plate length = 120 cm
    * plate width = 30 cm
    * plate thickness = 1 cm
    They need to be wrapped around a tube of 3 cm diameter

    * box width = 33 cm
    * box length = 60 cm
    * box height = 40 cm

    To calculate how many rolls I need to know the diameter of the rolled up plate.
    With that info, I can calculate the number of rolls in a layer and the number of layers in the box height.

    Does anyone have a clue how I can calculate this diameter?SpiralDiameter.xlsb
    Last edited by SjofaaSj; 04-23-2024 at 08:20 AM.

  2. #2
    Forum Moderator AliGW's Avatar
    Join Date
    08-10-2013
    Location
    Retired in Ipswich, Suffolk, but grew up in Sawley, Derbyshire (England)
    MS-Off Ver
    MS 365 Subscription Insider Beta Channel v. 2411 (Windows 11 23H2 64-bit)
    Posts
    87,887

    Re: How to calculate the diameter of a sprial.

    This is more a maths question than an Excel question. Do you have a sample workbook that you can share?

    Administrative Note:

    Is your forum profile showing the Excel PRODUCT that you need this to work for?

    Members will tailor the solutions they offer to the Office PRODUCT (Excel, NOT Windows) that you have. Please check that your forum profile is up-to-date in this respect. If you aren't sure, in Excel go to File | Account and report what it says below the MS logo at the top of that page. If your product is for Mac, please also state this.

    The three most recent Excel products are Excel 2019, Excel 2021 and MS365 - if you are using MS365, please give this name along with the version number in your profile (e.g. MS365 Version 2306). This is in the About Excel section further down the Account page.

    Thanks.
    Ali


    Enthusiastic self-taught user of MS Excel who's always learning!
    Don't forget to say "thank you" in your thread to anyone who has offered you help. It's a universal courtesy.
    You can reward them by clicking on * Add Reputation below their user name on the left, if you wish.

    NB:
    as a Moderator, I never accept friendship requests.
    Forum Rules (updated August 2023): please read them here.

  3. #3
    Registered User
    Join Date
    03-14-2012
    Location
    Belgium
    MS-Off Ver
    Excel 2010
    Posts
    15

    Re: How to calculate the diameter of a sprial.

    I just added a sample file with all parameters, but you are right, it is a math question (that I want to solve with excel as dimensions can change).
    And as I had no clue how to calculate this, that's why I tried in the forum.

    And yes, my Excel version at home is still 2010 (but 365 @ work).

  4. #4
    Forum Moderator AliGW's Avatar
    Join Date
    08-10-2013
    Location
    Retired in Ipswich, Suffolk, but grew up in Sawley, Derbyshire (England)
    MS-Off Ver
    MS 365 Subscription Insider Beta Channel v. 2411 (Windows 11 23H2 64-bit)
    Posts
    87,887

    Re: How to calculate the diameter of a sprial.

    OK - thanks. You'll need to wait for a maths expert to have a look.

  5. #5
    Forum Expert
    Join Date
    12-11-2011
    Location
    Netherlands
    MS-Off Ver
    office 365
    Posts
    3,435

    Re: How to calculate the diameter of a sprial.

    How do you calculate the circumference of a circle: Pi*D

    3.14*3.00= 9.42

    next diameter: 3+2=5
    3.14*5.00= 15.71


    Must be a fairly flexible material to be able to bend it around a 3cm tube.
    Attached Files Attached Files
    Willem
    English is not my native language sorry for errors
    Please correct me if I'm completely wrong

  6. #6
    Registered User
    Join Date
    03-29-2024
    Location
    USA
    MS-Off Ver
    365
    Posts
    38

    Re: How to calculate the diameter of a sprial.

    There are solutions that rely on the approximation of an analytical solution to the arc-length of the Archimedean spiral, but are cumbersome and confusing to work with:
    https://news.povray.org/povray.advan...povray.org%3E/
    So, over lunch, I was thinking along the same lines as popipio, since you're more concerned with the practical "diameter" of the entire roll, not just the instantaneous radius of the spiral at any given point.

    So you're basically just building up concentric shells of material.

    That'll give you a ballpark figure to work out the packing arrangement.
    Obviously if it's not an empty core or a full turn, then you're somewhere in the middle of one circle and the other, so your "diameter" will be ill-defined.

    SpiralDiameter.xlsx

    - Bill

  7. #7
    Forum Guru Pete_UK's Avatar
    Join Date
    12-31-2011
    Location
    Warrington, England
    MS-Off Ver
    Office 2019 (still learning)
    Posts
    25,160

    Re: How to calculate the diameter of a sprial.

    I think it will be very hard to wrap the plate of 1 cm thickness around a tube of 3 cm diameter - there is likely to be a lot of compression of the inner material, and a lot of stretching of the outer material. You could calculate this difference by taking a diameter of 3 cm (inner surface) and comparing it with a diameter of 5 cm (outer surface).

    As mentioned above, you could consider the rolled-up piece as consisting of a lot of concentric "tubes" of material. I would suggest taking an average distance through the middle of the material, i.e. the diameter of the innermost "tube" of material is 0.5 + 0.5 (=1cm) larger than the diameter of the tube that you are wrapping it on.

    I remember 20-odd years ago tackling a similar problem for a poster, but that was wrapping thin (-ish) wire on a bobbin.

    Hope this helps.

    Pete

  8. #8
    Registered User
    Join Date
    03-14-2012
    Location
    Belgium
    MS-Off Ver
    Excel 2010
    Posts
    15

    Thumbs up Re: How to calculate the diameter of a sprial.

    To all

    The dimensions you saw were only given as an example.
    Real dimensions are merely in millimeters for thickness and way longer in length (as you might have guessed).

    I do not need the superexact diameter but it's enough to have a good estimation in cm of the diameter to determine the number of rolls in the box.

    Thank you all for helping oud and especially Bill for the work you put into the file.
    Very usefull to achieve my goal.

  9. #9
    Forum Moderator AliGW's Avatar
    Join Date
    08-10-2013
    Location
    Retired in Ipswich, Suffolk, but grew up in Sawley, Derbyshire (England)
    MS-Off Ver
    MS 365 Subscription Insider Beta Channel v. 2411 (Windows 11 23H2 64-bit)
    Posts
    87,887

    Re: How to calculate the diameter of a sprial.

    If that takes care of your original question, please choose Thread Tools from the menu link above and mark this thread as SOLVED. You can also access the SOLVED tag by editing the opening post and choosing SOLVED from the drop-down to the left of the title box.

    Also, if you have not already done so, remember that you can reward anyone who offered you help towards a solution for your issue by clicking the small star icon (* Add Reputation) located in the lower left corner of the post in which the help was given. By doing so you can add to the reputation(s) of each of those who offered help.

  10. #10
    Registered User
    Join Date
    03-14-2012
    Location
    Belgium
    MS-Off Ver
    Excel 2010
    Posts
    15

    Re: How to calculate the diameter of a sprial.

    already done ma'am
    and only now I see that a SPRIAL was my interpretation of a SPIRAL

  11. #11
    Forum Moderator AliGW's Avatar
    Join Date
    08-10-2013
    Location
    Retired in Ipswich, Suffolk, but grew up in Sawley, Derbyshire (England)
    MS-Off Ver
    MS 365 Subscription Insider Beta Channel v. 2411 (Windows 11 23H2 64-bit)
    Posts
    87,887

    Re: How to calculate the diameter of a sprial.

    Thank you.

+ Reply to Thread

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. How to find the formula for circle diameter
    By metrostar in forum Excel Formulas & Functions
    Replies: 2
    Last Post: 03-21-2024, 11:11 PM
  2. [SOLVED] Need formula to calculate circumference from diameter
    By Col J in forum Excel - New Users/Basics
    Replies: 7
    Last Post: 03-09-2023, 06:26 AM
  3. [SOLVED] Increment diameter by 2mm
    By morton01 in forum Excel Formulas & Functions
    Replies: 3
    Last Post: 07-06-2020, 04:27 PM
  4. [SOLVED] Determine pipe diameter with 2 known values
    By **KJ17** in forum Excel Formulas & Functions
    Replies: 6
    Last Post: 07-15-2015, 07:25 PM
  5. Diameter which produces minimum cost?
    By Helpmeplease1 in forum Excel General
    Replies: 2
    Last Post: 03-16-2015, 06:21 PM
  6. CountIF same type and Diameter?
    By polevault in forum Excel Formulas & Functions
    Replies: 3
    Last Post: 07-03-2008, 12:47 AM
  7. [SOLVED] How can I set diameter of pie charts?
    By Rose A in forum Excel Charting & Pivots
    Replies: 2
    Last Post: 05-25-2006, 11:20 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Search Engine Friendly URLs by vBSEO 3.6.0 RC 1