Me and Zoe are watching a how to vid by this girl who does woodworking, and she is building a custom dust collection system for her shop. She was making a ply lid for the dust collection drum itself, and drilled a hole in the center of a piece of ply, then used a protractor, and a plastic tube tube with a string tied to it to lay out the disk for the lid. We looked at each other and both knew what the other was thinking: I can do the same for the gridlines on the upper saucer! I just need a tube the same diameter as the hole in the bridge. Then can use the string to lay out both radial and circle lines.

So I found something... the mortar shell from my Masterpiece scale God Bomber Transformer's shoulder cannon. I needed to make it a bit thicker with masking tape, but it now fits with just the slightest bit of loosness so it wil turn. The bottom is flat too so I can set it flat on the bench to make sure my lines are straight.[ATTACH=full]86934[/ATTACH]

There is one downside... i'll need to prime and paint the upper saucer before assembly of the saucer. I will mask off the edge though, so I can fill and sand the seam. But I think this should work out.