worlds best tail servo

[thomascoleman]

Just brought a 500L tail blows out regually, same with my mates

money no object - whats the best servo we can install

Was looking at the MKS-8010A, BK servo range 7005 or Savox..?

Need something ultra fast and torque

[Mr. Rmz]

Originally Posted by thomascoleman

Just brought a 500L tail blows out regually, same with my mates

money no object - whats the best servo we can install

Was looking at the MKS-8010A, BK servo range 7005 or Savox..?

Need something ultra fast and torque

I'm looking into this model, i saw someone dremeled the frame on left side and installed a full size servo.

That would be your best option.

If anyone knows how this is done please share some info and pictures

[vtown nick]

Nothing out there matches the BK DS-7005HV

You will need the mini top case sold separately.

There is a rjx version of this servo too. But torque and speed is higher than all the other mini options out there. I fly mine at only 6v and it can do funnels and good 3d at 2800 rpms governed and it holds great. Kick it up to 3200 rpms and beat the tar out of it!! This is a pro dfc too with the same gearing as your 500L

Also look into some zeal tail blades. They are a good deal wider.

[thomascoleman]

Do you have both part numbers for the bK?

[vtown nick]

http://www.helidirect.com/mini-size-...vo-p-36141.hdx

http://www.helidirect.com/bk-hv-mini...ed-p-32265.hdx

It mounts in the factory location but from the outside of the frame. You run the screws all the way through the black mount so you can see all the holes then but the servo up to the frame and run th screws in backwards. I'll get you a pic of mine.

[vtown nick]

[thomascoleman]

Perfect cheers mate.

Just trying to find UK stock

So no blow outs ?

[vtown nick]

Here she is

This is around 2900-3000 rpms on a 13t pinion which is about end of flight on a stock 500 and the tail is great. If your flying higher head speeds it will hold even better with that servo.

Trex 500 (2 min 58 sec)

[thomascoleman]

sweet cheers i'll order up

[Kap'n Krunch]

Originally Posted by thomascoleman

Just brought a 500L tail blows out regually, same with my mates

money no object - whats the best servo we can install

Was looking at the MKS-8010A, BK servo range 7005 or Savox..?

Need something ultra fast and torque

first make sure the mechanics are set up with no binding my tail slider moves freely with zero resistance with that being said im using the mks 9780 tail and 9767 on the cyclic im running about 2800+ with close to 13 degrees of pitch

[geouginator]

+1 on the BK DS7005HV, nice servo. I mounted mine on the inside of the frame, using a dremel with grinding wheel to cut slight arches in the plastic for the motor to fit through. Works great!

[Luigi_tuga]

This BK has monster specs.
I had a MKS bls 980 servo (made for turnigy by mks)for two good years (till i killed it with custom wiring for Copilot II), had same speed but at 6 v. Now talking about torque this BK has only a bit more than the triple, on a mini case

[vtown nick]

Originally Posted by Luigi_tuga

This BK has monster specs.
I had a MKS bls 980 servo (made for turnigy by mks)for two good years (till i killed it with custom wiring for Copilot II), had same speed but at 6 v. Now talking about torque this BK has only a bit more than the triple, on a mini case

Yessir thats why when people ask what is "the best" I have yet to find a mini servo with these specs. Hell it's better than half the full size out there! I run one on my rex as well as it comes stock on my goblin 500. Lets just say I don't have any tail tuning to do on those helis!! haha

[Bluelunatic]

Nick,

I did as you recommend, only I mounted the servo in a standard fashion and dremelled out the mount a little bit for it to fit. This BK servo with the Zeal 72mm blades are a whole lot more confidence inspiring. I'm flying full collective now. I've noticed some high speed wag only on very fast manuvers and I think I need to dial back the gyro gain a little and it should be fixed.

Thanks for the tip!

[Mateyhv]

Wow guys, the BK DS7005HV is really the best performance servo. I know its nice to have a great electronics, especially a fast and powerful tail, however I can't see the need for a 10.8 kg/cm servo for the Trex500 (ok for the Goblin 500/570). In fact if that torque is needed there is something totaly wrong with the tail setup, and sooner or later something will brake.

I say that because I have a 2.6 kg/cm servo and its enough for a total tail control. I think the BK is better employed in a 550 or 600 heli.

[Gladius]

It's not the "best", but a tail servo that is pretty damn good is the Protek 230S. You can get them from AMain for $44 right now.

I've had one on my 500 since I bought it 2 years ago. I've upgraded just about everything on my heli, but I'm still using the 230S because I've never had any problems with it.

[nabl74]

Originally Posted by Mateyhv

Wow guys, the BK DS7005HV is really the best performance servo. I know its nice to have a great electronics, especially a fast and powerful tail, however I can't see the need for a 10.8 kg/cm servo for the Trex500 (ok for the Goblin 500/570). In fact if that torque is needed there is something totaly wrong with the tail setup, and sooner or later something will brake.

I say that because I have a 2.6 kg/cm servo and its enough for a total tail control. I think the BK is better employed in a 550 or 600 heli.

Agree this force is really not required on a 500 heli, however, personally don't see this as a problem (as whilst the servo has the potential to provide quite a larger torque, if your tail is setup correctly and there is no binding, then this force should not be realised.

The real servo charactertic of interest is the servo speed.

Ive seen these servos in 450 size protos and even the goblin 380 with no issues.

BTW, the values you refer to are typically torque values.

Torque is not a force unit. T = F x d (or r), so your distance away from shaft on the servo horn is actually just as important.

Think of torque as an ability to twist something. You can extract force from it but that value depends on how far away the force is applied from the centerline of the shaft. The closer your connection to the shaft, the larger the force it can handle and vice versa.

We often look at speed rating of a servo for rapid response. Let say you have a 2kg/cm servo with 0.06s speed and a 10.8kg/cm servo with same speed rating. Under zero load, both servos will reach the goal in exactly same time. As your load gets near 2kg/cm, the first will crawl to a stop while the latter will still run (perhaps at a slower rate compared to no load but still fast).

So, sometimes, slightly slower but much higher torque servos will actually run faster than a faster servo with lower torque rating.

The BK give you the best of both worlds.

[Kap'n Krunch]

then what servo should we use for a 700 size heli if there's really a need to use a full size servo on a 400 size heli

I use the mks 9780 and the tail is rock solid

[nabl74]

There isnt really a need to use full size servos on most 500 or lower helis.

However from my understanding the 500pro and 500L had their tail ratios reduced to allow higher main blade rotor headspeeds). This really downgraded the 500pro and 500l's ability to provide a steady holding tail at lower head speeds.

Running your head speed at 3000+ rpm might fix most of this, but for us normal folk who are running a stock pinion 12t and max 2800 rpm head speed, a beefed up tail servo becomes the norm upgrade path towards better tail holding (particularly in more demanding 3d) like fast backwards flight, heavy pitch pumping etc at lower headspeeds like 2700-2800.

Whilst the bk7005 boosts some apparently amazing specs and i have it on my heli also , agree there are equally impressive servos that work just as well (rjx, mks etc).

Just saying thaz all.

[Kap'n Krunch]

just saying its not JUST the tail servo or necessarily lower head speed i've seen guys at the field with gain as high as 70 and 80 and there like I still cant get my tail to hold and then ask me how much gain i'm running , 20 percent.....

but what the original poster was describing (I believe) was the heli doing the twist in certain maneuvers with the stock align servo which improper setup or any type of binding would intensify the problem.. I would consider checking the mechanics first and that its buttery smooth with zero resistance. Mine I can easily shake the tail slider back and forth with the control rod disconnected