On Friday, November 24, 2017 at 10:44:35 AM UTC-8, wrote:
I need to do a short test run on my ventus 2cxm engine. The fuselage is on its cobra dolley in my garage, and I can wheel it into my driveway and tie the tail to a post. I'm nervous about this, in case there is some pitfall I haven't considered. Has anyone done an engine test run like this?

I've done it a few times, but you do need to think through the consequences.. I tied the tail off to something that wouldn't move, put some lumber through the spar box resting firmly on saw horses, and kept clear of the prop. Nothing bad happened and it didn't seem terribly dangerous. Once I did it with the tail tied to a stake in the ground and that wasn't immovable enough, so now I tie it to the truck or the forklift - both about 8000 lbs.

If you aren't completely sure about what you are doing, best to rig it.