quadcopter F450, bumped start. Damaged one propeller.

arduarn:
Oh lordy. Make sure you are wearing safety spectacles during future tests.
Until you are reasonably sure that it will fly, tether it to the ground so that it can only lift off a few centimetres.

yeah I was going to do that but had a confusion if motors will burn out. If the tethering is not too strong it is safe right? I am going with this option next.