RC India

Hi All,

I wanted to know which blades should I buy as spare for my Belt CP v2 315 mm or 325 mm. Orignally I got 315 mm on it but I know all other 450 size heli's use 325 mm so I am confused which ones should I go for price for both is almost same.  8-)

Thanks
Hellyflyer

The bigger blade size is better for normal flights (i.e. non-3D).  They tend to make hovering more stable. 

Beware that they also increase the chances for boom-strikes.

So are you saying that chances of boom strike are higher even in normal hover and a little forward flight

For such type of flying, boom strikes are by-products of crashes  ;)

So what I want to know is are there more chances of boom strike with a 325 mm blade as compared to a 315 mm even when I am doing some hovering and a little bit of forward flight. As what I understand is the bigger the blade disc (moving blades) the higher chances of boom strike so I can understand that from a 3d perspective but can it lead to boom strike if my forward flight is jerky like not smooth (little forward stop >>little forward stop etc...) on a 325 mm and not on a 315 mm

I am sorry if I am asking you too many questions on this small topic  :-\

Thanks
Amit

Nope, for this style of flying you should not see boom-strikes just from flying. 

That is what I was trying to say in my prior post, that the possibility for boom strikes for this type of flying are mostly when you crash, or if you let too much slop in the feather-shaft that connects the two main blade holders together.

BTW, 3D alone will not cause boom strikes either, it is usually either the parts used in the heli are sub-standard or the design itself has issues or parts have deteriorated over time causing "play" at the pivot points. 

I may be wrong, as I am new to helis but from what i have read 315mm and 325mm will not make a difference. Some companies measure the blade length from tip to tip and call it 325 mm ome measure it from mounting hole to tip and it comes to 315mm ( called many times the Align way of measuring )

Please correct me if i am wrong.

You may be correct but I have seen a video on youtube from Nuttcaze on Belt CP V2 which talks about the upgrades in which he clearly shows the difference in the 315 and 325 mm and I have read on other forums too stating that 325 mm gives you a more stable hover.

Anwar I wanted to know what is the difference between Wooden, carbon fibre and glass fibre blades in terms of normal flight and hover as Glass fibre is cheapest then comes wooden and then carbon fibre. which ones are better as i am at the learning stage

HellyFlyer

I have tried Align 315, 325 and 335 blades on my Trex 450 over various periods of flying.  So they do exist, and they offer different flight characteristics.  The longer the blade, the more stable the hover.

Anwar please answer

Here is my understanding + experience.

Wood blades : Advantages - Cheap, saves other heli parts by taking the impact itself, beginner friendly.  Disadvantages - Lower performance, not to be used for aggressive/3D flying and less durability.

Carbon Fiber blades :  Advantages - Sturdy, typically comes well balanced, high performance including support for 3D flights.  Disadvantages - Cost, possibility of other parts of head also breaking in crashes.

Glass Fiber blades - Between wood and CF.

Note that even CF and GF blades have wooden cores inside. More importantly, always remember that there is always a "you get what you pay for" aspect when it comes to blades too.

My experience was primarily with various Align blades. Started with the wood ones, and when I started doing sport/mild-3D, I started getting the glass fiber ones.  When I was crashing less often, I moved on to CF blades, and on to full 3D. 

I hope this gives you a general idea.

Yes it does thank you ;D

Here is a boom strike in the air. It is a spectacular sight (and heart-breaking at the same time) !

http://www.youtube.com/watch?v=jNFv0lfHQ3c

Most of the time, it is caused by some part of the head breaking in flight.  Other times, it is because of pushing a heli beyond its specs in setup or flying.