Santa brought a Dynavibe Classic Good ol Santa.

Balanced my prop the other day. Started at .34 in/sec and finished up at .03 in/sec.

I just put a new Sensenich carbon fiber prop on and it required several mods to reuse the existing spinner. I was pretty sure the balance would be off.

I was really impressed at how easy this unit is to use. I purposely pitched the blades to a finer pitch so I could get my full cruise rpm of 5350 on the engine.
Then I took three readings at that rpm and averaged them. All phase readings were within 2 degrees which I thought was really accurate.

My initial trial weight was 10 grams. I put 10 gms of washers on a spinner bolt and re-ran the engine. The location of the weight was perfect, but the amount of the weight was too much. I reduced the weight to 5.4 gms and ran the engine again. That proved to be the right amount of weight.

The radius from the center of the gearbox flange to the outside of the spinner, where the trial washers were mounted was 13.25 cm.

So, 13.25 cm x 5.4 gms gives 71.55 gm cms. Since the final weights had to be mounted on the spinner backplate, I removed the spinner and measured out 11.75 cm radius on the backplate. This was a good location to put on the final weight. Since I needed an effect of 71.25 gm cms, I divided 71.25 / 11.75. This gives a final correction weight of 6.08 gms. I cobbled together a bolt and nut and several washers and ended up with a final weight of 6.11 gms.

I repitched the prop blades for my normal cruise setting and put everything back together. It was too cold n too late to go flying, but tomorrow I am going down to Fort Worth to see my son. Am excited to fly the Fox with the new prop and a super smooth engine.

Funny - I heard my wife ordering some new furniture for the living room today. I think maybe an elf spilled the beans. Oh well, it's worth it.

The Dynavibe gets an A+ rating.

Rodney