The problem with internal funding is that, if the fund gets hit early or often, it can run out and, as you've discovered, the only option then is to pass round a hat.
If the club has used the funds for other purposes (fixing the leaking clubhouse roof), you might have a legitimate beef with the committee. Otherwise, it's a chance you take in order to save money by not buying insurance.
If you're flying at a number of clubs, or using other people's aircraft privately, you're better off buying Excess cover from an insurance company. It may cost a bit more, but it won't run out on you! You can usually pay the premium by monthly debit order, so that also helps.
I got my policy from Veronica at DJ&A. (011) 463-5550.