Anyone "Successfully" running 623's with 95mm Tail???

[jstarks]

Ok. Went back to 105s and the tail is working wonderful again!!!

As soon as my new slider comes in, I'll assemble the stock tail and try the 95s again and post back, if I have trouble.

[wlfk]

..

[wlfk]

Just a thought - going back to the original question.

You want the smaller blades in order to get longer flight times. Interestingly, when I changed from cheap 95mm blades to edge 105mm blades, my flight times increased by a minute or two. I was very surprised and at some point I'm going to go back and check that it actually was the blades that made such a difference.

That said, they say that tails take up from 10% to 20% of the total power of the helicopter - most sources give more like 10%. Seems to me that proportionally speaking it's probably not worthwhile going on too much of a crusade for a smaller tail. Have you checked flight times with the 2 different size blades?

[jstarks]

Hmmm.....well that's very interesting.

I was just thinking that the larger blades took more power but, I guess that once they are at speed they have to deflect less to move the same amount of air as the 95s so they may actually be more efficient.

I already ordered the new slider so I will go ahead as planned and assemble the stock tail with 95s. Then it will just be a matter of removing the grub screw and swapping it for the QUK tail with the105s. I'm actually anxious to see what the outcome will be.

I gotta say that it was weird and scary when I made that first high speed turn and the tail just stopped coming around, like it hit a wall!

J.

[wlfk]

I think that, theoretically, it should be the case that larger blades will take more power, despite being able to make do with a lower angle of attack. It might just have been that my edge 105 blades were more efficient than the cheaper blades, and that if I'd used edge 95mm blades my flying times would have been longer again...

[jstarks]

Well my 95s and 105s are both Edge so, I'll know in the next few days which blades have an affect (if any) on flight time.

Now my biggest reason for doing this is just to make the 95s work well, because apparently others are successful with them.

If it can work for others, it can work for me! I'll think of it as an exercise in tail tuning.

J.

[GimpyGolden]

I'm thinking the difference in flight time will be negligible if at all noticable
95's=5g and 105's=6.5gs so 3g's more total. I think there is more of a difference in weight between QUK tail and stock.

10% increase in length on main blade would be like switching from 600 to 660 which would be huge but I somehow don't think it will translate the same on smaller scale of the tail blades.

Either way let us know if the difference is significant.

[marcosp]

The effect is not the weight but the drag. The additional cm is at the tip which travels at a very high velocity and has a big impact on additional drag. However since the tail requires such a small amount of the total power a 50% decrease in efficiency or additional drag (ridiculous amount just to make a point) would mean instead of say 10% it consumes 15%. An additional 5% power requirement would mean you rob 3 seconds of every minute. On a 5 minute flight it means you would fly 4:45 instead. You can see it's negligible even with ridiculous inefficiencies and even if my calculations are absurdly gross since the effects on drag and changes in force through different required pitch are not linear at all, and increases in power requirement are not linear against time either, but the example is useful.

[SamurAchzar]

I don't think it's the blades, I think it's the motor. My Furion 6 is setup just as yours (Xera 4030/Jive 80HV), and I got a very bad tail kick until I went to 105. My friend has a part-for-part identical Furion 6 (same everything) other than an Align 700MX motor and the tail is way better.
Something in the combo of the Jive governer and Xera just doesn't work too good IMHO.

Read all about my troubles here.