This one? Seems a like you'd be competing with less expensive toy conversions if so. The crawler battlemech on the other hand...that would be something to think about.
I think the trick with a larger product would be to establish some freebees that you could give away at the lower level pledges and to offer the actual product at as much of a discount as you can afford. That way folks get a take away for backing the project just because it's cool, while others who are actually interested have an incentive to pay up front rather than wait for a general release. Look at some of the stuff in the art category
for examples of how to fund stuff that doesn't necessarily have a pay-off for all backers. And since the money never actually changes hands if you don't make the goal, I doubt there will be much in the way of bruised feelings.