HEIGHT: methodology questions

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   FPE creates a unique footprint name for each height, even if the other dimensions are the same. It has been practice, in various places, to NOT differentiate footprints in the library by height. Since a footprint is a 2D element, the same one can be used for components of various heights. This saves on library space and clutter.  it has been practice, in various places, to define height in the part, not the footprint. The part height will override the footprint height in Xpedition anyways. This method associates height values appropriately while allowing for library (footprint) optimization. Also, the 3D model is defined with height, and is assigned to the part number, so the same footprint can be used on multiple part numbers that have different heights, but use the same footprint.
  Sometimes, in the case of unique footprints (like on some connectors), height might be specified on a footprint name.
.
FPE associates a footprint to a part number (or a part number to a footprint), so i can see why a height is included (since part numbers have spec'd heights). Also, the very useful PDF output describes component dimensions (including height), not just footprint dimensions - this is indeed useful.
... however, i am trying to use FPE to create footprints and maintain a library that similar footprints can be reused. 
.
i am searching for a way to keep height out of the footprint name/spec, but keep it in the component spec (including 3D and PDF output. Any suggestions?

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
andygump Members Profile Send Private Message Find Members Posts Add to Buddy List New User Joined: 05 Oct 2023 Status: Offline Points: 4	Post Options Post Reply Quote andygump Report Post Thanks(0) Quote Reply Topic: HEIGHT: methodology questions Posted: 16 Oct 2023 at 8:44am
	FPE creates a unique footprint name for each height, even if the other dimensions are the same. It has been practice, in various places, to NOT differentiate footprints in the library by height. Since a footprint is a 2D element, the same one can be used for components of various heights. This saves on library space and clutter. it has been practice, in various places, to define height in the part, not the footprint. The part height will override the footprint height in Xpedition anyways. This method associates height values appropriately while allowing for library (footprint) optimization. Also, the 3D model is defined with height, and is assigned to the part number, so the same footprint can be used on multiple part numbers that have different heights, but use the same footprint. Sometimes, in the case of unique footprints (like on some connectors), height might be specified on a footprint name. . FPE associates a footprint to a part number (or a part number to a footprint), so i can see why a height is included (since part numbers have spec'd heights). Also, the very useful PDF output describes component dimensions (including height), not just footprint dimensions - this is indeed useful. ... however, i am trying to use FPE to create footprints and maintain a library that similar footprints can be reused. . i am searching for a way to keep height out of the footprint name/spec, but keep it in the component spec (including 3D and PDF output. Any suggestions?



Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5719	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 16 Oct 2023 at 8:52am
	Footprint Expert produces a footprint and 3D STEP model and imports them into a CAD tool simultaneously. The Height is strictly used for the 3D STEP model. Note: the Footprint and 3D STEP model name are identical for practical reasons.
	Stay connected - follow us! X - LinkedIn

jgregoire Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 19 Jan 2017 Status: Offline Points: 31	Post Options Post Reply Quote jgregoire Report Post Thanks(0) Quote Reply Posted: 02 Jan 2024 at 7:48am
	On our team, we very much care about footprint height. We assign a STEP model to every part, and we expect the height to be accurate (at MMC) for 3D collision detection. In OrCAD, STEP models are assigned to footprints, so parts with different dimensions need unique footprints. If there is no STEP assigned to a footprint, OrCAD uses the courtyard and height to render a 3D bounding box.

feynman Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 06 Feb 2020 Status: Offline Points: 12	Post Options Post Reply Quote feynman Report Post Thanks(0) Quote Reply Posted: 02 Jan 2024 at 1:08pm
	Our mechanical engineers use component STEP models for 3D collusion detection as well. In Pulsonix STEP models are also assigned in the footprint. And the part outline in the footprint has a "height" attribute for DRC during layout, where we sometimes define rules like "don't allow parts bigger than x in this keep-out area". So, although a footprint is 2D in theory, it cannot be agnostic of the part height. However, we don't overdo this with passive components. Capacitors have many different heights for the same package size, for example. So what we do here is defining a single footprint and a single STEP model per package size having the "worst-case" height.