How to tighten Vortex center hinge

[RJC]

When I set my Razor HD 10x42 to the appropriate distance between my eyes it collapses really quick, making one handed operation pretty much impossible. Any way to tighten this?

 

[packer58]

Look under the hinge cap in the front......

 

[RJC]

Look under the hinge cap in the front......

Tried that...spoke to Vortex today, they said there's no way for me to tighten it and I needed to send them back.

It looks like there's a spot for an allen wrench to fit in there but nothing I tried would do anything.