If you added the storage tray to the tongue of your Casita trailer, it was probably so you could put your generator there. For a smaller portable generator that you want to move around, you might want to just strap it down. But for a large generator like the one we just bought, it is best to secure the generator in a more permanent way.
I was a little unsure about how to go about this, but came up with a solution that I think works well and wanted to share it.
To firmly attach the generator to the Stromberg rack, I used thick steel plumber's pipe hanger straps. The strap comes in a long piece and you can cut sections to length using tin snips. The strap I got has 1/4" holes that are perfect for 1/4" bolts. I secured the generator in four places, with two bolts holding down each strap section. So that's a total of eight 1/4" bolts (1/2" to 1" long) and eight lock nuts.
The Stromberg rack doesn't have convenient 1/4" holes for these bolts, so I had to drill some. Fortunately, the entire top of the rack has a grid of small holes and it was easy to widen a few of those to 1/4" to accommodate the bolts.
I chose a four locations on the generator frame to put the hanger straps over. Then drilled out the tray holes and bolted them down. That is more than strong enough to keep the generator secure, even on bumpy dirt roads.
Everyone should be concerned about generator theft, because it is very common. Generators are valuable and easy to steal, so people will snatch them if they can. The sheer weight of our generator (110 pounds) is probably enough to prevent that and the bolts make it even harder to steal. But to be safe, we also wanted another layer of security.
For that, I used a length of heavy chain and a padlock. The chain loops through the generator frame and around the Stromberg frame. Yes, someone could unbolt the entire Stromberg rack and carry it away, but that would be very cumbersome and heavy. Generator theft is usually a crime of opportunity, so the goal is just to make it as inconvenient as possible to carry away. We think this is enough to accomplish that.
This generator was an upgrade from the Wen model we had before, so we're excited to see how well it works for boondocking. After we put it through its paces, I'll write up a review of our new generator.