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How to create a variable length LED Luminaire (lighting fixture)

6 REPLIES 6
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Message 1 of 7
Negaquark
3495 Views, 6 Replies

How to create a variable length LED Luminaire (lighting fixture)

 I was trying to make a variable length luminaire that could calculate the load automatically.

The problems I came across were dimensions & watts could not be calculated together, or the message

"Instance Parameters can't be used in Type Parameter formulas.

Type Parameter "Length" is driven by Instance Parameter(s): "Feet"."

 

First step is to determine the Load per foot. (15W as example)

Family parameter/Type

  • Name: Apparent Load
  • Discipline: Electrical
  • Type of Parameter: Wattage
  • Group parameter under: Electrical Loads
  • Value: 15VA

Next step is to determine the length. (4 foot typical length)

Family parameter/Instance

  • Name: Feet
  • Discipline: Common
  • Type of Parameter: Integer
  • Group parameter under: Dimensions
  • Value:4

Family parameter/Instance

  • Name: Length
  • Discipline: Common
  • Type of Parameter: Length
  • Group parameter under: Dimensions
  • Value: Feet * 304.8mm (or 1' for imperial)

Family parameter/Instance

  • Name: Calculated Load
  • Discipline: Electrical
  • Type of Parameter: Wattage
  • Group parameter under: Electrical Loads
  • Value: Feet * Apparent Load

Now for the Connector Element

Apparent Load should be Associated to Calculated Load

Label the Length Dimension

 

This works for a straight line LED luminaire.

 

For a circle with variable radius & perimeter try this:

Add

Family parameter/Instance

  • Name: Radius
  • Discipline: Common
  • Type of Parameter: length
  • Group parameter under: Dimensions
  • Value: 304.8mm

Family parameter/Instance

  • Name: Angle
  • Discipline: Common
  • Type of Parameter: Angle
  • Group parameter under: Dimensions
  • Value: 45

Replace

Family parameter/Instance

  • Name: Length
  • Discipline: Common
  • Type of Parameter: Length
  • Group parameter under: Dimensions
  • Value: Angle / 360° * 2 * 3.14 * Radius

Family parameter/Instance

  • Name: Calculated Load
  • Discipline: Electrical
  • Type of Parameter: Wattage
  • Group parameter under: Electrical Loads
  • Value: Length/1000mm * Apparent Load

 Label the Angle & Radius Dimension

 

6 REPLIES 6
Message 2 of 7
CoreyDaun
in reply to: Negaquark


@NegaQuark wrote:

 I was trying to make a variable length luminaire that could calculate the load automatically.

The problems I came across were dimensions & watts could not be calculated together, or the message

"Instance Parameters can't be used in Type Parameter formulas.

Type Parameter "Length" is driven by Instance Parameter(s): "Feet"."

 

Next step is to determine the length. (4 foot typical length)

Family parameter/Instance

  • Name: Feet
  • Discipline: Common
  • Type of Parameter: Integer
  • Group parameter under: Dimensions
  • Value:4

Family parameter/Instance

  • Name: Length
  • Discipline: Common
  • Type of Parameter: Length
  • Group parameter under: Dimensions
  • Value: Feet * 304.8mm (or 1' for imperial)

That error would be occurring because  the parameter "Length", although intended to be an Instance Parameter, is defined as a Type Parameter in the Family.

Corey D.                                                                                                                  ADSK_Logo_EE_2013.png    AutoCAD 2014 User  Revit 2014 User
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Message 3 of 7
CoreyDaun
in reply to: Negaquark


@NegaQuark wrote:

...The problems I came across were dimensions & watts could not be calculated together... 


You can create a formula to directly associate the load with actual length - You just have to make the length unitless:

 

Total Watts = Watts per Foot * ( Length / 1' - 0" )

 

Attached is a family basically demonstrates my method, in case it's of any help. (Revit 2012)

Corey D.                                                                                                                  ADSK_Logo_EE_2013.png    AutoCAD 2014 User  Revit 2014 User
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⁞|⁞ Please use Mark Solutions!.Accept as Solution and Give Kudos!Give Kudos as appropriate to further enhance these forums. Thank you!
Message 4 of 7
Negaquark
in reply to: CoreyDaun

Those were just sample errors I came across while trying to create the luminaire.

This is a "How to thread", not a "Please help me" thread.

I remember reading a post with this type of problem, but could not find it again once I solved it.

Message 5 of 7
csamaniego123
in reply to: CoreyDaun

How do you manage to edit the length if you set it as instance in order to use it in a formula? Also, how is this lenght is not working with Label. And why i cant modify Length parameter in the Family Type.

 

So many questions.

 

Thanks in advance

Message 6 of 7
Negaquark
in reply to: csamaniego123

CADastrophe's version does not use an integer variable to control the length.  It does allow you to stretch it manually.  You can add an Integer Parameter as shown.

 Integer.png

Most fixtures are set to a "per inch" or "per foot" value.  If you use Shared Parameters, you can get your Tags to read the values.

 

Message 7 of 7
Negaquark
in reply to: Negaquark

Small correction:

Length Formula should be ( WperINCH * 1")

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