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!"
Another question probably to the members this time.
Can anyone explain the reason behind the attachment of the control bar (the bit with the two rod ends, if someone has the official name for this let me know) to the torque tube. The use of, what looks like, plastic spacers is interesting. Is this some sort of vibration damper?
Also the plate just above the "plastic" spacers seems to be bent down is this a photo distortion, by design or overtightening?
Chris you are amazing how you get it done!
Look at this chick,guys, she is putting us to shame....
And Chris, it is disturbing to males that you can get away with using the kitchen table too!
Thanks for sharing this it could really save a life!!!
Good morning Chris!!!I feel like I'm just spinning my wheels!
I feel as if one moment I'm getting it fixed & then respected opinions point out good-sense improvements in the construction materials! ... another step back to something better.... eventually( one can ONLY HOPE!!!) ... MORE :flame:'n delays!! :Cry:
what I found when experimenting with springs in control systems is that you can fly it for many hours and think that you have it right until you hit that up or downdraft at a fuel load , bank angle and speed that all comes together and the rotor has a mind of it's own until it develops a nasty shake that threatens to tear the machine apart, then it is all good again but you will never trust it after you have it go wrong all by it's self but no matter how hard you try you can't make it happen again under controled conditions.