Headspeed and tailgear ratio

[Sp00tn1k]

Hi guys

I recently changed my pinion to the bigger one on my E7se. I was getting 1850 rpm with the small pinion and my 500 kv motor and 80% throttle input to my kosmik 160. With the bigger pinion and 85% throttle I am at my desired headspeed of 2250. When I did this whole procedure I came across the 2 recomendations in the manual to 1. only run 106 mm tail blades and 2. change the tail gear ratio to lower the tail rotor speed. Now I was wondering if these suggestions are cumulative or alternative haha. Do I change both or do I change one of the two?

What happened to me as well is, that in my sheer stupidity I didnt recognize that my kosmik after reprogramming and changing the motor pinion recognized 100% throttle and I flew one flight with probably about 2500 rpm. I am a bit worried that the airframe might have taken dmg where I cant see it. I checked the whole tail and the only thing I have found is that the brass tube in my zeal tailblades was torn to the back of the tailblade. Besides that everything was looking good to my eye. Tail output shaft was not bent and so on. Do you have any suggestions where to look or what to change apart from the tail blades?

Thanks for your help.

Cheers
Dave

[Chris Sexton]

4.9:1 (stock E7se tail ratio) can handle 2250 with 106 tails. It's a bit high but it will work. You just might need to dial back the tail gains a bit.  Ideally for 2200+ RPMs you should drop to 4.5:1 tail ratio and run 106mm tails.  But as I said, you can leave it alone if you wish.

AS for your concern about 2500.  I repeatedly run my E7 speed at 2590rpm, it can handle it It's a tough bird.  The things I check most often with head speeds that high are my thrust bearings and dampers.  Still running the stock of both after an entire season of speed runs.

Matt builds these like tanks

Welcome to the Synergy Forum btw.

[Sp00tn1k]

Hey Chris

Thank xou for your reply. That took my concern away. I knew they were built like tank, but when I saw that the brasstube in the tailblade had actually shifted, I was pretty concerned. I love my Synergy E7 and also my E5.They are both awesome birds and fly sooo nicely and locked in!

Thx for the welcome too. I already wrote one thread concerning the e5 a while back. So I am not completely new but still, thanks alot.

Of course I hope to meet you guys soon, I'd like to get in touch with some of the synergy enthusiasts. Probably at ircha this year. I am planning to go, but I will have to come a long way from switzerland

Cheers and thx again

Dave

[Mike Spano]

i know 2 people who have had Zeal main blades BREAK in flight. one of them has had 2 sets break. personally, i wouldn't trust them, i would replace everything with rails.

[flyalan]

Mike. Can you pm me the names of those folks.  I Have started carrying them  in my store and would like to hear some input directly from someone that had a failure. . have flown the 700's main blades and 105 tails and like them to be honest. No failures yet. I figure is Tareq doesn't break them they are probably ok?

Cheers
Alan

[Sp00tn1k]

i know 2 people who have had Zeal main blades BREAK in flight. one of them has had 2 sets break. personally, i wouldn't trust them, i would replace everything with rails.

Hey Mike

Thank you for the reply too. Well for mainblades I got the MS Composit Rapid, which I absolutely love. Never had a failure on thoae blades and I fly them for the better part of 2 years now. On the tails I went with Zeal because I couldnt find any Rails at that time. I considered it akward too, that a tailblade would actually brake like it did, just because of 4 minutes high rpm. But of course I was not sure if it was the blade quality, or the enormous force.

Right now I have a different problem. I got Vibs on my tail, and cant figure out why. I cant feel them in flight, but yesterday I got rid of the blades and just spooled up and cab feel harsh vibrations. I think it is the worse, where the boom support rods are attached to the boom. I tried a couple of things. I tried to take of the tail, everything was running fine without the tail. I tried to move a bearing slightly on the torque tube, turnes the torque toob arround. I chacked if the tail outputshaft was straight. The only thing I didnt try so far is to replace the tail output shaft and the tail hub (that thing that works like the tail spindle shaft).

Do you guys have any idea wha that could be?

Cheers
Dave

[Mark Dean]

Dave,
Your vibes could be either part you mentioned. Other things that pop out in my mind are tail gear mesh too tight or your bearings on the tail grips aren't seating correctly or are notchy.

Mark

[Rob Cherry]

Did you figure out this issue? I'd replace the tail shaft bearings for sure!  2500 HS with the 4.9:1 ratio tail is serious rpm at the tail and requires perfectly balanced, high quality tail blades, among other things. You mentioned the brass sleeve was worn inside the tail blade roots? That could easily result in a very bad tail resonance and ruin the bearings very quickly.