Propeller Balancer

myminifactory

I've had this little "finger balancer" knocking around in my field box for as long as I can remember, but it was practically useless. After years of ignoring all the sage advice from seasoned fliers about making sure propellers are balanced, I was testing an engine and the vibration was noticeable enough to make me wonder if it was time to heed their wisdom. The magnetic type balancers may offer very little rolling resistance, but they seem to introduce some false positives/negatives with the polarized fields; there are YouTube videos demostrating this. The Dubro balancer looks like a nice unit, but because I am thrifty, I decided to try something like what is shown here. This little balancing stand will accomodate fourteen inch propellers. (I haven't confirmed that, but with a twelve-inch prop, there is still a good inch of clearance left on the bottom, so that would mean a fourteen would fit.) The steel wire you see in the half-moon shaped perches is carefully epoxied into place, with no epoxy on the top of the wire. Soft copper would have been a better choice as it is easier to form, but any kind of metal would offer lower rolling resistance to the spindle, making the balancer more sensitive. A drop of sewing machine oil doesn't hurt. Be sure your work surface is as level as you can manage; check your results by rotating the entire balancer stand 90 degrees on the benchtop.