This is an interesting thread to me because I do think it is something we can become too complacent with. I just recently wacked my right thumb with the prop. (15x4) What had happened was that I had always set up my stuff on the right side of the table but recently got a new field box. With the new field box everything is opposite of the old one and it just wasn't working out to set it up on the same end of the table that I usually do. (our field is set up with picnic style tables and there is two flyers per table, one on each end) Anyway I started setting up on the opposite end of the table and it threw off my routine. What happened was that I started my engine with the elec. starter and reached across the prop to set it down and the prop wacked my knuckle of my right thumb. It hurt like crazy but didn't bleed much. It could have been much worse.