Gretsch Honeydipper cone keeps collapsing..

equalsql

The spun cone on my Honeydipper steel guitar collapsed on me. There is a cover over the top of the biscuit bridge so it is not the weight of my palm that caused it. I purchased a replacement Golden Gate cone from Hobgoblin music and retuned from edge to centre I.e. EEBAGD and everything seemed ok. However after leaving the guitar for a couple of days I found the new cone had collapsed as well.
Is this a problem with using cheap cones.. I.e.is it worth ponying up for really decent proper spun cone.. or is there something more sinister going on here I wonder?
I'm using Michael Messer 15 - 56 guage strings.

KDS

Post issue on Micheal messers website, lots of helpful people there

Kristo

Those strings are too heavy for standard tuning on the high strings.