Donate Now Goal amount for this year: 3000 USD, Received: 1207 USD (40%)

Results 1 to 7 of 7

Thread: PSU formula

  1. #1
    Junior Member
    Join Date
    October 20, 2015
    Posts
    14
    Current Local Time
    07:00 PM

    PSU formula

    Hello

    I have created a formula for my LORU and LDR fittings, now I need one for a PSU fitting.
    I have been working on the formula and it works with NESTED IF STATEMENTS.

    I do have a problem though. It moves in the wrong direction.

    PSU formula-wrong-psu.jpg
    When I create a formula like this: if(D1 = 80 mm, 50 mm, if(D1 = 100 mm, 80 mm, 100 mm)) the right PSU size appears but it moves in the wrong direction as you can see on the photo. What should I do to lock it to the center of the duct? I have pinned it and locked and aligned to ref.planes.

    Thank you,
    Christian :-)

  2. #2
    Member
    Join Date
    September 16, 2015
    Location
    Darwin, Australia
    Posts
    171
    Current Local Time
    03:30 AM
    Could you please upload the family?

  3. #3
    Junior Member
    Join Date
    October 20, 2015
    Posts
    14
    Current Local Time
    07:00 PM

    PSU formula

    Here is the family I'm creating the formula for. :-)
    Attached Files Attached Files

  4. #4
    Junior Member
    Join Date
    October 20, 2015
    Posts
    14
    Current Local Time
    07:00 PM
    Nothing? Any help?

  5. #5
    Forum Addict josephpeel's Avatar
    Join Date
    May 3, 2012
    Posts
    1,396
    Current Local Time
    07:00 PM
    You need to place dimensions from the ends to the center line, and then click the "EQ". This will keep the lengths equal and make sure the object stays centred as you change the length.

  6. #6
    Junior Member
    Join Date
    October 20, 2015
    Posts
    14
    Current Local Time
    07:00 PM
    Brilliant! It works. Almost.
    When I reduce the duct from 125 to 100 the PSU dosen't follow. It works fine from 200 to 160. What is wrong?

  7. #7
    Forum Addict josephpeel's Avatar
    Join Date
    May 3, 2012
    Posts
    1,396
    Current Local Time
    07:00 PM
    well... it all depends on how you have set up the family.

    The 'best practice' for building parametric families is to start with the dimensions you want to change and in which direction they will change.
    Then, model this with only ref planes and dimensions until you get it to work how you want (change the parameters regularly as you build it up, to see that it is working correctly)
    Finally, Make your 3D geometry with extrusions etc and lock them to the ref planes so the size is controlled by the structure you already set up.

    If you follow that kind of process it is much easier to see where something is wrong or to change how it works. If you begin with a 3D model and then try to make it parametric it can get messy quickly, until you get errors and you dont know what is causing them..

    (Note; I dont always follow my own advice.. I do bad stuff like controlling dimensions of lines in sketches, putting stuff on the faces of other extrusions etc.. but start with the correct way first :P )
    Last edited by josephpeel; February 4th, 2016 at 12:16 PM.

Similar Threads

  1. Formula help
    By BLothian in forum Architecture and General Revit Questions
    Replies: 2
    Last Post: October 24th, 2014, 08:20 AM
  2. Formula
    By adamheon in forum Architecture - Family Creation
    Replies: 2
    Last Post: October 9th, 2014, 03:32 AM
  3. Formula both yes or not
    By srwsl in forum Architecture and General Revit Questions
    Replies: 1
    Last Post: April 15th, 2014, 02:14 PM
  4. Schedule formula (is there a formula expert in the house?)
    By John McCamont in forum Architecture and General Revit Questions
    Replies: 8
    Last Post: September 9th, 2011, 09:50 PM
  5. Formula Help
    By Alex Cunningham in forum Architecture and General Revit Questions
    Replies: 9
    Last Post: March 30th, 2011, 10:27 PM

Tags for this Thread

Posting Permissions

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