To stretch or not?

[trillian]

I have a Helix with the G260RC engine that I bought BNF and I am almost finished setting up.

My question is: Would it be worth the effort to fit the longer tail in order to be able to run a bit longer blades, maybe not go all the way to 800s but be able to fit 720s / 750s etc. ?

My flying style is smooth 'big air' and FAI type stuff.

The thinking behind this is that the extra disc size would be good but I don't know if the G260 can handle the extra drag. The stretch kits are very reasonably priced and I'm keeping an eye out for sales over here and I can get the NHP 742mm blades at a good price.

[jharkin]

By stretch, do you mean going to the TRex 800 trekker boom?

I'm building mine now with the 700DFC boom (800mm boom length). With the old taller mainshaft (98mm above the upper bearing collar) on it we mounted a set of Rail 716s and Rail 106 tails and measured there is a bit over 1 inch of clearance between the blade tips and the tails when bending the main blades down to full deflection.




You could probably get away with 720s on this setup, clearance wise (but you have to have the DFC boom and tall mainshaft).

Anything longer definitely wont fit.



As to whether your engine will handle it, that I dont have the experience to answer... one of the more knowledgeable guys probably can. I can only guess to go really big like 750 you might need a different ratio?

[trillian]

Originally Posted by jharkin

By stretch, do you mean going to the TRex 800 trekker boom?

I'm building mine now with the 700DFC boom (800mm boom length). With the old taller mainshaft (98mm above the upper bearing collar) on it we mounted a set of Rail 716s and Rail 106 tails and measured there is a bit over 1 inch of clearance between the blade tips and the tails when bending the main blades down to full deflection.

You could probably get away with 720s on this setup, clearance wise (but you have to have the DFC boom and tall mainshaft).

Anything longer definitely wont fit.


As to whether your engine will handle it, that I dont have the experience to answer... one of the more knowledgeable guys probably can. I can only guess to go really big like 750 you might need a different ratio?

Yeah there's a kit that comes with the 885mm boom, TT and everything you need and it's very reasonably priced. The stock 700 boom will allow 710mm mains with 105 tails and maybe a milimeter or two more but that's about it.

I'll definitely be flying it first with 710s and I probably shouldn't even think about any mods but seeing that stretch kit got me thinking :-o