( new thread getting away from that bottom feeding thing)
Update. Sensenich said they would probably ship the prop. back tomorrow. There was nothing wrong with the prop. except the damaged spot(as I expected), tracking and angle are fine. They had to reduce dia. by 1/4" (1/8"/blade)to maintain required tip profile.
Meanwhile I kept looking at the Wood Culver 74 X 50 that I tried on the Spezio which the O290 couldn't turn(like 1900 rpm static) . I figured after that it had relatively more pitch compared to a metal Sensenich. Anyway I bolted it on and it tracked ok so I tried it figuring static would be over 2700( Static is 2400 or so with the 74DM6 X 58)
Surprise, static was only 2550 rpm so why not try it out. I had thrown it on torqued but not indexed so this morning I installed it correctly and tried it out.
It worked fine. 2650 RPM in a 90 mph climb and cruise was about the same 120 IAS @ 2500 rpm.
Overall it is much smoother w/o that typical Sensenich roughness from 2100-2300 or so. That said, while overall less vibration it's still there?
If this was my first flight in the airplane I probably wouldn't take note of the vibration but that will no longer ever be how I react. I no longer take vibration as a norm. Just got a call from Sensenich and the prop will go out today and be here tomorrow. Probably won't do anymore until next week. My grandson is here and we are fishing and shooting.
Alas I can't use the wood prop anyway. With me and full fuel we are at the aft limit of GG.
My plan is to fly the repaired 74DM6 and see how bad the vibration is? Hopefully it's within a range that will give me confidence to go 15 min. (31 miles)north to Bedford for a dynamic balance. At least there is a decent valley most of the way. Then maybe the dynamic balance will tell me something, maybe point to the Lord mounts? At best the vibration will be cured and the oil filter clean in another few hours and I can go on with my life.
But frankly I'm spooked by the whole thing!
Thanks again for help and/or cautions,
Jack
Update. Sensenich said they would probably ship the prop. back tomorrow. There was nothing wrong with the prop. except the damaged spot(as I expected), tracking and angle are fine. They had to reduce dia. by 1/4" (1/8"/blade)to maintain required tip profile.
Meanwhile I kept looking at the Wood Culver 74 X 50 that I tried on the Spezio which the O290 couldn't turn(like 1900 rpm static) . I figured after that it had relatively more pitch compared to a metal Sensenich. Anyway I bolted it on and it tracked ok so I tried it figuring static would be over 2700( Static is 2400 or so with the 74DM6 X 58)
Surprise, static was only 2550 rpm so why not try it out. I had thrown it on torqued but not indexed so this morning I installed it correctly and tried it out.
It worked fine. 2650 RPM in a 90 mph climb and cruise was about the same 120 IAS @ 2500 rpm.
Overall it is much smoother w/o that typical Sensenich roughness from 2100-2300 or so. That said, while overall less vibration it's still there?
If this was my first flight in the airplane I probably wouldn't take note of the vibration but that will no longer ever be how I react. I no longer take vibration as a norm. Just got a call from Sensenich and the prop will go out today and be here tomorrow. Probably won't do anymore until next week. My grandson is here and we are fishing and shooting.
Alas I can't use the wood prop anyway. With me and full fuel we are at the aft limit of GG.
My plan is to fly the repaired 74DM6 and see how bad the vibration is? Hopefully it's within a range that will give me confidence to go 15 min. (31 miles)north to Bedford for a dynamic balance. At least there is a decent valley most of the way. Then maybe the dynamic balance will tell me something, maybe point to the Lord mounts? At best the vibration will be cured and the oil filter clean in another few hours and I can go on with my life.
But frankly I'm spooked by the whole thing!
Thanks again for help and/or cautions,
Jack
Last edited:
