Custom Parts Workflow

This entry is part 4 of 4 in the series Custom Piping Components - Plant 3D

Our posts on custom parts has been one of the most popular of all time. However, I feel like there are some things that could be a little clearer. In this post, I’ll pull from some of the content at AU, and add some more information on working with custom parts. Some of this post will be pulled from:

Here are some of the best practices for developing your custom part library:

  1. Create a project at a shared location that will become your custom parts library project.
  2. Planning your part
  3. Create parts using a good work flow.
  4. Understand how to deploy custom parts

Custom Part Project

The purposes of creating a custom part project is to provide a backup of created parts, organize existing parts, and share created parts to users. Custom parts need to be tested inside of a project environment, so a single project that holds all of the custom part files helps with testing and maintaining a library. Of course, the location and contents of the project is up to you, but here is one example of how it may be organized. In this example, the test models/blocks are stored by type and manufacturer.

Note that there are two different locations being monitored, under 3d drawings which is where the drawings that contain the blocks used with PLANTPARTCONVERT, and Related Files which is where the “plain” AutoCAD block is. You should keep a copy of the block before PLANTPARTCONVERT is run on it so that you have a backup of the geometry.

Planning your Part

Before creating a custom part, you should examine the existing Plant 3d shapes to see if a similar shape already exists for your part.

Open a catalog, and click create new Component.

Click Advanced Shape options and browse the classes and available shapes.

The Piping component type (Elbow above) will determine the category the item is displayed under once added to a spec.

If you can find an existing shape, you will save time using it as custom blocks have to be created for each size, and moved around when sharing library content.

If you can’t find a suitable shape, you need to browse the existing catalog content to locate a similar part for isometric content purposes. For example, if you are making a 4 port valve, you should look for a 4-way valve in a catalog. The purpose here is to identify the port order so that the selection of ports in your custom part matches the expected order for isometric symbols.

The iso symbol type and Iso symbol key are critical in producing clear isos. The symbol type controls allowable ports (in some scenarios), as well as appearance, annotations, and location within the bill of material.  For example, in order to use a 4-port valve, you must use Valve-4WAY type.


Here’s a list of isometric symbol types.

We’ll update it soon to account for the new 2017 capabilities.

A list of symbols is available in the De-Mystifying AutoCAD Isometrics pdf:

A sample of various types of symbols is on page 25:

Custom Part Workflow

Creating custom parts can be tricky as at times you may need to fix port locations, or remodel content. To help minimize issues, here are the steps recommended for creating a new custom part.

If you are using a Custom parts project, you would first create a model drawing in the project manager. This model will eventually contain all of the sizes for the particular valve, instrument, or fitting that you are creating. In your project drawing, perform the following steps.

  1. Model the objects a 3d solids, and then set the color of all of the objects to ByBlock. By setting the color to ByBlock, your custom objects can have its color controlled by the project settings for colors.
  2. Set the UCS to world. Having a custom UCS set current will change the insertion orientation as a piping component.
  3. Align your model so that it’s flow direction lies in the positive x-axis, and that its height is along positive z. The proper alignment before creating the block controls the insertion orientation as a piping component.
  4. WBLOCK with the current objects being turned into a block. This provides a block reference in the current model to use PLANTPARTCONVERT on later, while creating a backup.
  5. If you are using a Custom Parts project (see above), add the backup files to the related files section so you can open it from the project manager.
  6. Based on the previously selected similar part, use the PLANTPARTCONVERT command to pick ports in the order necessary to match the isometric port order.
  7. Test your custom part by using the custom parts palette (PLANTCUSTOMPARTS).

    1. This button can be used to launch the PLANTPARTCONVERT command
    2. If you used PLANTPARTCONVERT on a block in the current file, you can choose that block from the model for insertion
    3. Enter port information. With default project settings, flanged components should have pressure class and facing filled out.
    4. Insert the part into a pipe line to test insertion and connection behavior.
  8. Create an isometric with your part in line to make sure it matches your expected behavior.

Custom Part Deployment

After testing your custom part, you have a choice to add it to a catalog/spec or have users re-use your custom part from the Custom Parts project. If you choose the latter, they can open the custom parts palette, and use the Import Block from DWG and select your source project model to pick the necessary part. Importing the block requires no further deployment steps.

Adding your custom part to a catalog or spec requires a few further steps. In a catalog of your choosing (please don’t use the stock catalogs), start a new component and choose block-based part. Choose the part information, and select the number of ports. Notice that the port selection may also be done by typing in the number of ports, if you need a higher number of ports than is in the list.

Add your catalog information like normal parts. The final step is to pick your custom block. This selection will be the saved Plant 3d model file that contains the block that your ran PLANTPARTCONVERT on. Not the file that we stored under Related Files.

After adding it, save your catalog and add your part to the spec and test it in a model again.

Sometimes, people end up moving their content folder after creating custom parts. The key to sharing custom parts is to locate the CatalogSupportFolders directory in your Content folder. When a part is added to a catalog, the block and thumbnail images get copied to a directory (named from the catalog) inside of the CatalogSupportFolders directory. As long as the CatalogSupportFolders directoy gets moved/copied wherever your shared content folder location is, Plant 3d will be able to find your custom parts.


Series NavigationCreate new Symbols for Isometrics in AutoCAD Plant 3D