Unsupported boom

[jhunter]

How are they getting away with this? Is the boom stronger than a normal one? $60 euro for the boom doesn't sound crazy. Pricy yes but in Line with a $2700 kit.

[Mojak]

Off of the Banshee website:

30mm strutless boom crafted in fiberglass. Probably is stronger....



Technical features

3-speed belt drive

Automatic tail rotor drive belt tensioner/-spring damper

Main drive belt tensioner

30 mm fiberglass, strutless, tail boom

Straight swashplate linkage

Extremely small, compact design with high torsional stiffness

Center of gravity close to the rotor plane

Double (x2 separate units) needle bearing clutch

*

Technical*specifications

Basic weight of the mechanics including canopy*(not including: motor, servos, regulator, batteries or rotor blades): 1.65 Kg´s

All up weight with standard equipment (3xBLS452, 1xBLS251, Jive 120+ HV, Pyro 700-52, BeastX, Maniac3 710 mm, 115 mm tail rotor blades, canopy): approx. 2950 g´s

Main rotor blades:* 690-720 mm

Tail rotor blades:* 105-120 mm

Motor: 65 mm diameter max.

Main rotor speed: 1000-2300 r.p.m.

Variable reduction ratio between motor and intermediate shaft: 1:4 – 1:2.88 (18–25 drive belt pulley)

Reduction ration between*intermediate and main rotor shaft: 1:3

Ratio between main rotor and tail rotor:* 1:5.54

Battery cell size:* Maximum 60 mm width and 60 mm height

[Mercuriell]

I got some 300 CF booms made up for my Diabolo and they are sufficiently stiff IMHO not to need boom supports - I guess it comes down to the weave pattern and the thickness of the wall - I believe the Diabolo was originally tried too without the supports but there was some softness of tail authority MC did not like.

[Mixmaster Pilot]

I have carbon fibre golf driver shafts that can take a real pounding without issues. But they cost a lot more than a regular heli boom.

[marcosp]

But it says fiberglass, not carbon fiber. Many helis have true carbon fiber booms and still need boom supports, I though fiberglass was what Banshee team chose for some reason. Which is harder?

[Dumbthumb75]

Guess something got lost in translation. Grammar...

I noticed that too, and checked their german page.
There it says : "30 mm CFK Heckrohr ohne Streben".
Googled CFK to make sure : "Carbon Faserverstärkte Kunststoffe" , so carbon it is.

[Mercuriell]

On the parts shop it reads:

Tail pipe 30 mm (Code: B-H16)


From the highest quality carbon fibre

[marcosp]

So only difference with the Diabolo is alu vs CF? Both are 30mm. I wonder why Gerd didn't go with CF to retain one boom support or none. Maybe not wanting to increase the cost and making CF boom mandatory.

[Mercuriell]

Originally Posted by marcosp

So only difference with the Diabolo is alu vs CF? Both are 30mm. I wonder why Gerd didn't go with CF to retain one boom support or none. Maybe not wanting to increase the cost and making CF boom mandatory.

Gerd tells me he tried CF but had bad resonance problems - I will try it but unfortunately my custom CF booms are 0.1mm oversize so I will have to turn them down (I hate machining CF)

[marcosp]

Well, alu boom is a pretty good vibe absorber. I don't care for one or the other as long as there is a belt tensioner. The Logo with alu boom was a pain with temperature variation. With CF it is almost perfect. What I mean is I don't mind the designer choosing CF over alu unless there is a clear advantage, and vice versa.

[helicraze]

I prefer CF due to thermal reasons, but thats about it, cost wise aluminium!