Step 1:
Choose the Place option from the top ribbon bar, navigate to Castor and Wheel or use the search function. Choose 'Castor Board'.
Step 2:
The software will now sense all available faces on which a Castor Board can be placed. Hover over and click on the relevant place holder box, the chosen castor board location will now turn Blue. Press the Green tick to apply. (usually located to the left)
Step 3:
You will now be presented with this view.
(note you can drag the control interface around the window if you like)
Step 4:
You now input the values you would like the castorboard to maintain it's relative size to. The green box (castorboard) will update as you enter values and click into the next box.
You have now created your dynamically sized castor board.
(remember you can edit these measurements at any point by entering the edit mode and clicking on the castorboard)
Step 4a:
This step is optional.
If you want to move the castorboard away from the case, to account for a spacer panel just enter this value in the 'Offset from Case' box.
Step 5:
Press the Green (apply) tick and the castorboard will create itself as a part.
Now when you change the case size, the castorboard will update it's sizing accordingly.