Contact
Make the issue reproducible.
For questions or corrections, email yardfill.helpful594@aleeas.com. This is the existing verified shared public forwarding alias for the owner's free-tool portfolio. It forwards to the owner's existing mailbox; a new inbox has not been created for this tool.
For arithmetic
Include the exact mass, x and y rows, both selected units, the result you received, and the answer you expected with its calculation. A saved text report already contains the model inputs. Explain whether a component's coordinate refers to its own mass centre or to a corner, since the distinction changes what the input represents.
For the page
Include the affected page, browser, approximate screen width and the action that caused the issue. State whether a unit change, a reset or a report export was involved. A brief description can be enough; do not include private account details.
There is no live chat, user registration or customer account system on this site. The tool is free, and this contact address is for feedback rather than a promise of a response time or a professional assessment of a physical assembly.