Chris T...... It seems like this is drawing to an end & I still have alot of questions.
First off.....what exactly were you doing when the bolt broke, prerotating ?
A. READ post #16
When the bolt broke, please describe what happened ?
A. READ post #16
Were your rotorblades damaged also or just the prop ?
A. READ post #16
Damage found to date - pitch pivot bolt - broken& torque tube needs replacing, .... prop - 2 blades, keel, & RHS control rod- post #166
I thought that Powerfin was out of business....did you ever consider another brand ?
They moved to Utah! Another brand ??? - ask Larry why ... I'm just a rookie & starting with a "proven" rig set up by some-one who has been doing this gyro-designing for 16-odd years!!!
I took some pics of my AC head. The bolts are tight & roll with the head. I would like to hear an explanation for what seems like alot of extra parts used on Larry's heads.
:noidea: ASK LARRY!! So would some other readers ... see post #169
Ultimately...have you drawn any conclusions on why your bolt failed ?
My conclusions - based on all the information ( + observation & opinion) available to date from Larry,Jake, JeffT, Vance, other Butterfly / clones owners findings using the same pitch/roll pivot-torque tube set-up & the Arrow lab test results on the broken bolt .......
. Primarily the bolt was installed ( By me) & not torqued to specs - as the build instructions to do so were not clear- or specifically stated on the relevant pages of Aurora rotorhead assembly & I did not understand that pivoting/castle nutted bolts needed to be torqued like the nylox regular nuts...... obviously NOT ALONE in this error as Glenn's , Steve's & apparently Tim's were also ONLY "finger-tight"
Second the - expert we paid to check my work & finish/build-assist also missed finding it !!!?????
Third - my gyro has had an abnormal number of pre-rotations for the hours on airframe (38) - due to my student-learning status!
4th - my MLS PR Possibly? had abnormal issues - with pulleywobble - causing vibration & rotorhead stress .......
....Larry has shown exemplary customer support in providing ( no charge) parts for repairs & also new upgraded pulleys to smooth the MLS operation! ( post #166)
5th - Due to my inexperience ...in spite of a "gut feeling" something was off about that part of the rotor-head( & I did examine it extra hard on pre-flight & put it through the range of movements - that day)..... I still missed the subtle "signs" & not drawing Desmons attention for a second opinion...( "wisdom -in-hindsight thing") ...as we were wanting to get going with my training that day! ....... the typical dreaded CASCADE of events that lead so often to aviation accidents!!!
Yep I sure had powerful guardian-angels protecting me that day!
What did the lab say ?
see post # 158 on P11
How does the other bolt look ? (side to side pivot bolt )
The roll axis pivot is not a bolt - but 2 steel dowels pressed into the pivot block - & held with spring-steel plates!
How about the spindle bolt ?
I have not yet removed the rotorhead to tear down .... I expect to this week... will post pics when I do!
I have purchased new bolts from a different manufacturer & plan to rebuild the rotorhead using these - even though the bolt tested - "in-specs for AN hardware!"