- May 26, 2019
- Cape Town
- R44/22 H269/300 MD 500 Magni (all); Xenon RST; DTA; ELA; MTO Trojan
- Total Flight Time
- Stoped counting at 2000
How does a Robbie ever get 540 Rrpm? There is a very interesting calculation for every percent above 100% for Rrpm before destruction and I fear that 540 will be higher than what the spherical bearings could withstand?I agree with Xavier.
My calculation says that the rotor of an ELA would have to be rotated at more than 500 rpm to lift 450 kg in ground effect with no forward speed, and this would require 70 hp shaft power.
And 300 rpm still gives it a lift of 170 kg. This, due to the Aerodynamic pitch setting of 3 degrees.
Tilting this 20° backwards, then, it pulls the gyro 55 kg backwards.
My calculation also says that you need a collective pitch of 7.2° for the rotor of a Rob R22 turning at 540 rpm to lift 620 kg in an OGE hover. 104 Hp on the shaft seems then necessary.
in fact I will go on record and say that once it’s seen that it will need to go in for inspection ?
however we digress and we still cant seem to agree that winding up the rotor will aid take off distance and I’m still not in agreement with that? It would be great if you could do some calc to expand on take off distance using standard airfoil gyro blades and various Rrpm’s prior to actually rolling (and point of rotation) because my thinking and training is that the gyro disk is in fact like a big drag Shute and is not in anyway like a helicopter
if we were all debating this in a class with the aid of a white board I would gladly hash out my thinking and support it with drawings?
please explain the comment about pulling the gyro backwards at 55kg as this ties in with what I’m saying, you need this force and the thrust from the prop to enable flight? And things sort themselves out with thrust and aft stick at say 7 degrees? For level flight?