Lol tail blades hum has long been shown to be caused by the tail blades.. not the bell crank

 

Sure. I use cheap $4 105mm CF tail blades and do not have tail hum.

Some say it is related to TT... Actually nobody really knows what is going on with it so we probably talk about some harmonic vibes.

My friend had Goblin 700. Crashed it hard in 9th flight and did not rebuild. Cost of rekit was high. He got Agile 7.2 instead. He had problems with it. Mainly related to weak belt and smaller pinion he used. He is strugling with Chase, he likes X3.

Out of big birds he put 800mm blades on Assault like me and we both did not have problems with mechanics for months. It is not fancy nor very expensive heli but tail is rock solid at higher RPM.

Actually RPM and proper gearing seems crucial at bigger helis. Not servo, not gyro, not mechanics but RPM of main and tail rotor can influence tail performance most. That is just my experience.

One of my colleagues sold TDR because he likes high RPMs and smack. TDR gearing seems to work better at lower RPMs. He did not like tail performance at high RPMs.

I use realatively cheap electronics and parts. They did not fail on me with two exceptions this season:

I had really bad crash of my 800 related probably to radio signal loss. My fault I placed antenna to close to main frame. High speed, no TH, nose into the mother earth. I was surprised I lost only main blades, $4 plastic canopy and three plastic ball links. Other parts were intact except slightly bent main shaft I replaced and slightly bent tail boom I still use after streightening it up.

Once overtightened bolt mounting tali grip broke. My fault. Never use excessive force to tighten such bolts. Use spacers. This time I performed perfect autorotation and did not even break landing gear.

Sorry for off topic.

 

A good Tail system should have counterweighted grips - so easy to do.. .not sure why hardly anyone is doing it..

Align started doing it for a while on the 450s but seem to have fallen off doing them too?

The counterweights dramatically lower the load on the tail servo... so unless there is an adverse effect I'm unaware of, why aren't they all using them ?

 

Good point. Tennis Racquet Effect, Chinese Weights. Here are papers explaining how it works:

https://www.google.pl/url?sa=t&source=web&rct=j&ei=FzdLVLqLBsTfPaHWgIgM&url=http://www.helifreak.com/attachment.php?attachmentid=408413&d=1364786988&ved=0CCsQFjAA&usg=AFQjCNHpH5NEy3gmsSZTzZzv9EGWn5qPLw

http://www.rcheliwiki.com/Chinese_weights

 

Yea - I call them "Chinese Weights" also but wasn't sure if that was the real name or not..

 

There is no crime in being a rush fan boy, the crime is overlooking them. Peace out


Sent from my iPhone using Tapatalk

 

'Twas just a gentle wind up Jeff.
@feral can like what ever he wants, I'm not worried in the slightest.


Citizen #186

 

Except for dji phantoms if I ever buy 1 y'all have permission to shoot at will

 

Ok you can be the second shot after we blow the Phantom out of the sky.


Citizen #186

 

Sounds bloody good to me pencilnose

 

Have been reading about rc-tek tail grips which are available for most size helis and their ability allow the servo to work more efficiently and to improve tail holding power by evening out the forces
Thinking about getting a set of the below to improve my tail performance. Lot of people who have used them on Trex have claimed big tail performance improvements.
http://www.rc-tek.com/store/i2rc-hi...-blade-tail-grip-assembly-with-hub-p2320.html


The logic being their design and ability to improve tail holding / performance is that a normal grip will naturally want to spin with zero pitch on the blades. To twist the blades away from zero pitch requires an increasing amount of force. The chinese weights change the moment of inertia, so that the force required to rotate the blades changes much less over their range of travel. Therefore, your tail servo doesn't have to work so hard, and can respond faster to required pitch changes.


Here are some videos showing the improvement that a chinese weights approach design provides.

Thoughts?

 

Actually SAB copied 1:1 all tail diameters from Align. Align parts will fit Goblin tail.

(This info comes from Benji. He had G700 and now has second Goblin 700 Competition.)

 

@gonehelimad Chinese weights are standard on tge avant mostro .. must be one of the tuffest yet still smooth tails ive owned (srimrok faifa still holds the mantle )

 

Kasama kept my attention for a long time. It looks like jewelry job.

I wonder why it is so rare.

Probably:
- price tag
- over ingeeneering, very high parts count
- ugly shape of canopy this is subjective I do not like it.
- frame looks very fragile
- lack of global parts availability

I wonder if they really use exceptional materials.

Looking at photos it definitely stands out of the crowd.

I would love to flight check one.

 

@utrinque I had a 2 year love affair with the faifa owning 3 off them .. all destroyed in high speed crashes -230kmh frames are the sacrificial piece and from memory around $99au each . That +parts here in oz was the biggest issue . Yes they do use titanium bolts etc and it was over engineered but who doesnt like that ! Really stood out in the crowd & was the fastest thing on the planet at one stage . mine clocked 238kmh .
One thing that was an issue .. the small tsil boom used to flex & I had a mad vibration issue in the tail drive I couldnt sort ... off to the big knackery in the sky (stripped and sold as parts to fund my current gauix7

 

after trying Align , Synergy , SAB,JR,Kasama,TDR,Banshee and Mikado

Mikado Logo 700 Xxtreme tail knocks all of the above out of the ball park , so solid and such a beautiful feel its amazing . gives such confidence to really push .

 

Ive only got a poor little logo xxtreme 480. But tail sure holds well.

 

Did you fly the same RPM, tail gear ratio, same tail servo and FBL unit? Did you use governor? It can deteriorate tail performance.

 

Please check this pdf:

https://www.google.pl/url?sa=t&source=web&rct=j&ei=rWtLVcT4Icj_ygOLp4CIBA&url=http://www.helifreak.com/attachment.php?attachmentid=408413&d=1364786988&ved=0CCwQFjAE&usg=AFQjCNHpH5NEy3gmsSZTzZzv9EGWn5qPLw&sig2=qlIOUHWBi1UjykquNZ3tEg

 

1 have 3 banks setup on every heli with 3 different headspeeds , only ever used Vbar and I use Ksomik gov , its all about getting the right motor and gearing for the job .