Just a thought - since you’re 3D printing the bobbins for your HB size P90s, have you considered printing a bobbin that uses a rail magnet instead of individual pole pieces ?
Hi there. Do the p90s you sell on your website (old timer p90s) use the full sized bobbin you mention here as opposed to the single coil in a humbucker case?
Was starting to watch this video and I am a bit confused... I know is an old video, but why are you printing the bobbing flat? If you print vertical you won't need any support.
It does need support if rotated 90 degrees for the core of the bobbin. The problem is that the finish does not come out as aesthetically pleasing on the top of the bobbin. It's also more difficult to remove the supporting material that way around.