The thing which really did it for me this time was trying to strengthen the whole frame. Screws didn't really work as I couldn't get them tight enough to securely hold the individual pieces in place. I then tried using dowel rod as pins (which meant I could easily take it apart whilst designing) but my measurements were off slightly which meant other parts didn't fit.
I'm gonna put in on the back-burner for a while and probably come back to it in the new year. My colleagues at work have suggested I try and make something for Christmas so I think I'll concentrate on that.
There's also that tin can model to work on but that can wait...
Hopefully I'll have a more productive blog post in the future.