I built a canard pusher LongEZ and about 10 years ago I purchased a Balance Master for a Lyc O-320-E2D with a 3 Blade Catto. I used a Dynavibe to do the dynamic balancing, but still had some vibration which I thought might be removed by the Balance Master.
Pushers are hard to get smooth at all flight conditions. Using the Dynavibe and testing at different RPM I have rarely gotten it smooth at all RPM. I found that inverting the prop from a Y at #1 TDC to an inverted Y made a huge difference and was much smoother at all RPM before using the Dynavibe. Once I found the best orientation, the Dynavibe seemed to point to a good solution. At least that is my experience.
The Balance Master didn't have any effect on my vibration. I think it is limited by the amount of fluid inside. In a tractor configuration, it might do some good if you had a good balance to start with and were trying to trim it up, specifically if there were differences at specific RPM and a few tenths of grams balance weights.
I will say he, was MORE than annoyed when I sent it back for a refund. But I did get the money back.
