Magknight
We discussed the advantages and disadvantages of this pitch change device here
http://www.rotaryforum.com/forum/showthread.php?p=636454#post636454
From experience tracking many different rotors using a dynamic balancer, I find that the design you propose is more difficult to track accurately because you cannot measure easily the adjustments you have made. I struggled with an Arrowcopter, we got there eventually but it took much longer than using shims. Your method works but is more hit and miss than Fara's shimming method.
Averso used to have this setup (that's how it got into the Arrow copter) but they went away from it because it was too hit and miss and it's their later design that's in the AR1.
Fara I thought that Averso were putting the coning angle in the hub bar now, I must check on that.
Another question, why did you go for two double row bearings and not two 40° angular contact bearings (7206 style) ?
Mike G
Thanks for the feedback. I didn't find it difficult, but then I didn't mess with it after it was balanced. The initial balance took only a couple of quarter turns on one side. I do understand your point though, there's no way to know where you're at.
On the pre-cone, I thought it was a recommendation from the German CAA (or whatever they'd call themselves) during Arrowcopter's certification. It sounded like they were concerned with all brands rotor systems similarly and were wanting the cone put in to reduce stress on the system.
Abid, I didn't mean to start any questioning of what you've done. It looks well thought out and a better design than many out there!
Fara
Sorry to hijack your thread with Magknight.
I'd like to congratulate you on doing away with the legacy ELA pneumatic system that's heavy, complicated, maintenance unfriendly and leak prone. I never understood why other eurogyros blindly followed ELA when the Magni cable operated pre rotator and rotor brake are so simple and effective. I can understand ELA being probably pushed in the early days by the marketing need to be different to Magni so as not to be accused of cloning the M16, but the others had no excuse not to think it through and simplfy their systems as you have done.
My only regret is that you didn't put in a Magni style flex drive pre rotator. The legacy ELA right angle drive with all those universal joints and sliding shafts is high maintenance feature after a couple of hundred hours, I've seen quite a few broken right angle drives (mine after 700 hours) and failed universals (mine also). The latest Magni flex drive is bullet proof, although the earlier ones did have problems.
I also don't like that the vertical shaft is spinning a couple of inches from the pasengers head, if it ever failed and started whirling around I dread to think what would happen, if a flexdrive fails it stays in the outer casing. Also the flex drive allows you to bring the stick back when pre rotating.
Anyway congratulations, I'm sure you're going to rapidly become the major American player, you've understood what your market :usa2: wants and you've hit the ground running.
Mike G