Originally Posted by SD Blue

I'll have to say that I like yours the best, of what I've seen, for a homemade version. The "factory-approved" version isn't tilted but is formed to hold the coil in a centered position on the plate. From both of the models shown here, maintaining centering on the end plates would be a major concern of mine. (It is hard to determine that feature in the photos)
Even the "factory" tool is scary and you need to make sure everything is in its proper detent to prevent slipping to one side and the bottom plate is locked in place.