Lead by example. It seems like you've done a great job with your personal fund raising already, but keep on going! You'll hear a lot about "continuous improvement" in robotics, which applies at every level, right down to fund raising. Keep up the good work! Giving up never got anyone anywhere.
The (somewhat unfortunate) simple truth is that, it is nearly impossible to evenly distribute work like this. The people who are dedicated to it are the people who get the job done. The people who are not sound like they're either not very into the club to begin with, or are expecting something for nothing. If they are in the first category, then there's not so much you can do, other than trying to get them into your team (which some people simply just won't do).
If they are expecting something for nothing, then you
eventually should make sure this situation is rectified. There are already some suggestions in this thread, such as giving these members lower priority for travel, a required minimum funds threshold, having to make up the difference with participation fees, or simply guilting them into it. But this should not be your first priority. If a job needs to get done quickly, use the people who have had success with it. Yourselves.
If you find yourself getting angry at a problem, distract yourself by fixing it.
EDIT: I believe this is the post Jane is referring to. I agree, an
excellent point.