Steve_UK
Active Member
- Joined
- Oct 15, 2010
- Messages
- 3,886
- Location
- UK
- Aircraft
- I'm not a pilot but have been lucky enough to fly in Mi-24 Hind, Mi-2, Mi-17, Lynx HAS3, Gliders, GA
QUESTION #4
Question 4 :
Why Titanium ? isn’t it very expensive
Answer :
With the reports of cracking hub bars and cracking aluminium rotor blades on some European gyros we decided to look at better materials to use in our new gyro
We worked with the Australian defence force academy who had done studies on cracks in gyro copter Aluminium hub bars and were continuing their studies on making hub bars from composite materials
While we found this to be a very strong and most suitable for the purpose it was very labour intensive which increased the cost to an unaffordable amount.
We then looked at replacing the Aluminium hub bar with Aerospace grade 5 Titanium but Titanium is 60%heavier then Aluminium , so we looked at replacing the stainless steel frame , control tubes and rotor head with titanium to offset the extra weight of the Titanium hub bar.
With more and more Stainless frames showing cracks in the European gyros we decided to look at a material that could handle the constant pulse and vibrations of a rotorcraft .
Titanium has twice the elastic properties of both Stainless steel and Chrome moly so this helps to absorb vibration
Unlike stainless steel and chrome moly that can get stress cracks Titanium is very resistant to cracking and doesn’t rust or corrode and is up to 5 times the yield strength of stainless steel and 2.5 times the yield strength of Chrome moly, but almost half the weight.
Question 4 :
Why Titanium ? isn’t it very expensive
Answer :
With the reports of cracking hub bars and cracking aluminium rotor blades on some European gyros we decided to look at better materials to use in our new gyro
We worked with the Australian defence force academy who had done studies on cracks in gyro copter Aluminium hub bars and were continuing their studies on making hub bars from composite materials
While we found this to be a very strong and most suitable for the purpose it was very labour intensive which increased the cost to an unaffordable amount.
We then looked at replacing the Aluminium hub bar with Aerospace grade 5 Titanium but Titanium is 60%heavier then Aluminium , so we looked at replacing the stainless steel frame , control tubes and rotor head with titanium to offset the extra weight of the Titanium hub bar.
With more and more Stainless frames showing cracks in the European gyros we decided to look at a material that could handle the constant pulse and vibrations of a rotorcraft .
Titanium has twice the elastic properties of both Stainless steel and Chrome moly so this helps to absorb vibration
Unlike stainless steel and chrome moly that can get stress cracks Titanium is very resistant to cracking and doesn’t rust or corrode and is up to 5 times the yield strength of stainless steel and 2.5 times the yield strength of Chrome moly, but almost half the weight.