View Full Version : mainblade tip to tail blade clearance
05-15-2006, 02:48 AM
What is the minimum clearance needed between the tip of the main blade and the tail blades. I have a 60 size Xcell gasser. I was running 690mm blades and 105mm tails. I switched out to 720mm mains and the clearance to the tail blades looked too close if I was into 3d style flying. I am only using it for AP duties and no 3d style flying. I did however install some stock Freya X-spec "blue" plastic tail blades (92mm??) which were shorter. I test hovered the set up and the tail holds OK. The clearance is actually more now with the 720mm mains and 92mm tail than with the previously used setup of 690mm mains and SAB 105mm tails. Is there any issues I might have running the shorter tail blades such as working the rudder servo harder and hotter. The freya tail blades come stock on the Xspec 90 size so I think the should be OK. Last option is installing a longer boom which is 33". I presently have a 31.5" boom and don't want to change it if I don't need to.
05-15-2006, 09:12 AM
720mm mains and 105mm tail blades on a 31.5 inch boom.
I would think the mains and the tail blades are overlapping and will touch if a hard back cyclic command is given.
The longest mains I have used on a 31.5 inch boom is 700 mm. The longest tail blades I used with the 700 mm main blades was 100 mm tail blades. That combo on 31.5 inch boom and there very little clearance.
If you want to use 720 mm main blades without problems. Your going to need to get a 33 inch boom.
06-02-2006, 03:09 AM
I extended the boom. It got the 33" tail boom and torque tube installed. Now I got a question about the tail pushrod. It's way too long. What length should I cut it to? I have a X-cell gasser with the tail mounted servo.
06-02-2006, 08:29 AM
The pushrod needs to be 1.5 inches longer than the pushrod you had on the 31.5 inch boom.
33 inches minus 31.5 inches = 1.5 inches.
So just measure the tube of the pushrod you was using on the 31.5 inch boom. Cut the new pushrod tube 1.5 inches longer than the old pushrod. Install the ends the same as the 31.5 inch boom pushrod and your ready to go.
07-14-2006, 09:33 AM
I don't think there is any minimum clearance. That is, if they don't overlap you're OK. As someone else pointed out, if they do overlap you run the risk of them touching but in all the report I've read of this happening, the heli still flew. It just shredded the tips of the tail blades and chipped the mains. I guess you could break the tail hub (and that would be bad).
07-14-2006, 09:35 AM
Also, you mentioned going to a longer boom. That would fix the problem, and I'm sure you've thought of this, but along with the pushrod you need to change the torque tube. It's not a cheep swap.
07-14-2006, 12:18 PM
I did end up installing a longer boom 33"