Thanks!!
Now for our bottom plate for the air cleaner.. In order to keep the filter located properly (keep it from moving around) we decided to add a bead to the bottom of the plate.
Then the plate is trimmed to a circle, and the thumbnail dies in the Lennox used to start the shrinking process around the edge.
https://youtu.be/Vy30NeziryY
We then jumped on the Erco kick shrinker to flatten the uneven surface..
https://youtu.be/B1Jg_9BfDNc
https://youtu.be/Xlu2LsUNcj0
And repeat. Repeatedly. We have two or three more rounds to go and we can start tipping and stretching.