Has anyone balanced a prop on a ROTEC motor?
Has anyone balanced a prop on a ROTEC motor?
OK. DynaVibe did the trick. Made my own mount since DynaVibe didn't have one for the radial.
Started with a good static balance so the prop (75X55) wasn't too far off - 0.14 ips.
Once I was in the 0.05 ips range, I was in the noise. Repeatability was 0.04, 0.07, 0.05, etc.
Flys pretty smooth.
IMG_E9855a.jpg
Those are good numbers for a piston engine, although I have never balanced a radial engine.
Phil Nelson
A&P-IA, Maintenance Instructor
KF 5 Outback, Cont. IO-240
Flying since 2016
Agree. On the first DynaVibe run, the prop was 0.14 ips. I was surprised that the prop DynaVibe’d that well with only the static balance. So I made several more runs and obtained similar results. I added 20 gm where the DynaVibe indicated. I was stunned and very pleased when the result was under 0.1 ips. So made several more runs under 0.1 ips but could not obtain clarity for further weight placement. My original goal was 0.1 ips so I’m very pleased with this result. BTW, the prop tracks to less than 1/8 inch. I would be very interested to know the prop balance experience of other radial drivers.
If I may make a suggestion, make a wooden block to fit under the aluminum shelf (tab??) that you have the transducer mounted to.
Epoxy the wooden block between the transducer tab and the yellow rpm pickup. The wooden block should touch the vertical wall and the tab.
The tab is vibrating as the engine is running. Picture a cantilevered structure. The additional vibration from the tab could be influencing your amplitude readings.
It is a simple fix and will add damping to your homemade fixture. Nice job by the way.
So nice to have a smooth engine/prop to fly behind.
Regards
Rodney
Hi Rodney,
Sounds right. I'll give it a try. Thank you for your input.
Roger