7HV rotorhead on servos

[Lorbeer]

Hi Guys!

Planning on getting a 7HV. Would like to ask those of you who have crashed a 7HV if the servos held up good? Been reading some stuff about the direct flight control head that the 7HV pioneered is hard on the servos compared to a traditional linkage type head, and can damage them in the event of a crash. Any thoughts? Also, how is the durability of the belt drive? I tend to be a Tareq type of flyer. Not the 3D part but the crashing part! LOL ;-P. Sadly I have the tendency to wreck a heli whenever I enjoy it too much and take it to the edge too soon. So crash worthiness is a top criteria for choosing a heli for me.

[mtuccio]

Originally Posted by Lorbeer

Hi Guys!

Planning on getting a 7HV. Would like to ask those of you who have crashed a 7HV if the servos held up good? Been reading some stuff about the direct flight control head that the 7HV pioneered is hard on the servos compared to a traditional linkage type head, and can damage them in the event of a crash. Any thoughts? Also, how is the durability of the belt drive? I tend to be a Tareq type of flyer. Not the 3D part but the crashing part! LOL ;-P. Sadly I have the tendency to wreck a heli whenever I enjoy it too much and take it to the edge too soon. So crash worthiness is a top criteria for choosing a heli for me.

All DFC designs are hard on servos in a crash. When you are dealing with 700 sized helis this is minor collateral damage in the scope of things. Servo gears are cheap and can easily be replaced after a crash. It's the re-kit for the model that hurts your wallet....You really shouldn't be worrying about crashing when you get into birds this size....Sometimes it happens and you just need to pick up the pieces and move on....Trying to aticipate what is going to happen in a crash is nearly impossible since no two crashes are the same.....

[salmonson63]

In my experience the 7HV is not too bad on servo gears. I have had 4 crashes on my machine and 2 of them have been pretty bad, and I have yet to strip a set of servo gears. The saving grace is in the swash driver ams. Since these arms are made of plastic I have found that these will break before you will actually strip a set of servo gears, at least this has been my experience. Also in general these arms add more dampening to the whole head allowing us to use regular dampers. So unlike most other DFC head designs that have a rigid connection from the main blade grips to the swashplate the 7HV does not. In my opinion the 7HV head is somewhere in the middle between a tradition FBL head and a standard DFC head when it comes to abuse on servos. Hope this helps!

[GimpyGolden]

My 7Hv has been good in this regard, only servo gear to ever strip was tail.
The swash-grip links tend to pop off or snap unlike other brands.

Belt has stood the test of time for me. 500+ flights without any breakage or wear.
I think the tensioner helps here. In a crash it will allow belt to give some instead of snapping. Good for when you bend a boom too, allows some slack.

[Daniel880516]

Don't know if it applies here or not, but I had 2 crashes with my Atom 500, and one awful frame rekit crash with the 6HV, the servo gears all survived, but I have small dents in 2 of my DS610. CC 80HV failure I've seen a friend's Trex 600 with bellcrank strip servo gears in a crash
Otherwise 700 size, are definitely not meant to be durable in a crash, they are all heavy! The 7HV is very beefy though!

[Lorbeer]

In that case, I guess I'll slap on some Savox 1258TG on the 7HV I'll be getting. For some darn reason, these (and it's twin, Align DS610M) last well in my crashes. Never had to replace a gear. Must be the Titanium gears or something. Now it's time to find out if that will hold true in the 7HV!

What headspeeds are y'all running on your 7HV's? Was thinking of the "median headspeed" of 2250 with a Scorpion 4525-520kv.

[Ah Clem]

"Been reading some stuff about the direct flight control head that the 7HV pioneered is hard on the servos compared to a traditional linkage type head, and can damage them in the event of a crash."

Direct Flight Control is the product name of a similar looking head manufactured by another company. It is not the same design.

The Compass/TracX (SZ) heads may look similar, but appearance is where the similarity ends. The Compass heads have flexible drive tubes, rather than rigid links between the blade grip arms and the swashplate. The tubes allow the head to flap normally, and are also a sacrificial part, in the event of a crash.

salmonson63 was pretty much right on (with the exception that the drive tubes do not play a part in the damping equation-the allow the head to flap normally, and allow the use of dampers of various firmness).

While I have not crashed a 7HV (yet), I have crashed several machines equipped with the 600 size SZ head (one particularly nasty and inverted, which was pretty much of a re-kit for the helicpopter). The drive tubes shattered, and one of the blade grip arms wrinkled (requiring replacement). The servos were not damaged in any of these crashes.

Oddly enough, the spindles were fine, too (the main shafts were not).

Servo damage in a bad crash with an SZ head, should be no worse than on a conventional head with conventional linkage.

[GimpyGolden]

Originally Posted by Lorbeer

What headspeeds are y'all running on your 7HV's? Was thinking of the "median headspeed" of 2250 with a Scorpion 4525-520kv.

2250 is pretty lively.
With 4525 and a good Gov you will have good performance at a broad range.
With my rewound Pyro I am running 1800-2050, still lot's of PoP.

Play with different speeds to see what suit's you, it's the only way to know.

[Lorbeer]

Originally Posted by GimpyGolden

2250 is pretty lively.
With 4525 and a good Gov you will have good performance at a broad range.
With my rewound Pyro I am running 1800-2050, still lot's of PoP.

Play with different speeds to see what suit's you, it's the only way to know.

Yea I guess you're right. I've just gotten so used to my Aligns that usually use that headspeed. Ah Clem, thanks for sharing that valuable piece of info. Now you've given me a big problem: I want my 7HV tomorrow

[heathy]

Well, I think I can safely say that I'm the number 1 7hv crasher on the planet. I've got 2 and they've both been smashed up bad. No servos damaged yet, outrage on 1 and align ds615's on the other. Usually the elev servo arm strips the splines and in most cases 1 or both the delrin drive tubes pop off. Sometimes snap.

This Heli is a tank.

[crf69]

14t 4525-520 yge gov

87% 2280.

insane!

[Andyzboy]

I've crashed a couple times, each time stripping the arms rather than the servos. Running 610's and JR heavy duty plastic arms, delrin rods and servo arms tend to go for me. Servos holding up well but I'm sure each crash isn't great for them