JR HV Servos
 

In my Onas I have switched to using some new JR HV servos. These have allowed me to remove the regulator and run straight 2S Lipo power. On the elevator I am using JR DS378HV's. These are in the same case as the low profile 378's that were in the airplane before, but they are now rated for 2S. On rudder I am using an 8911HV servo. This is way overkill for torque, with a rating of over 400 oz/in. But it is a fast, extremely smooth servo. The ailerons were the biggest change for me. I have always used 8411SA's, as I have always found the extra torque to feel better to me. But Pete Goldsmith recommended I try the new 3711HV servos. These are the size of the 3421, and they seemed like they might be to small to me. But I have to say they are working great. Before anyone asks, all of these servos are metal geared with no plastic option. But they sure do seem very tight and smooth to me.

So if you want to get rid of one more piece of electronics in the model, you can use these HV servos and drop the regulator.

RE: JR HV Servos
 

I was thinking of trying the same with the new futaba, was wondering if they might feel jumpy.

RE: JR HV Servos
 

Tony,

does the performace decrease as the voltage decreases?

thanks,
chris

RE: JR HV Servos
 

I haven't noticed that at all after 8 flights on a 900mAh pack.

RE: JR HV Servos
 

Tony, what did you do for the esc? Can they handle the higher voltage?

Jim O

RE: JR HV Servos
 

Hi Jim,

I did nothing for the ESC. The Phoenix 85HV I'm using seems to have no problem.

RE: JR HV Servos
 

Hey Tony,
Can you mix & match these servos with a standard setup using a regulator? I'd like to try these on my ailerons only, but leave the rest of the setup alone...
OR
Do I need to replace everything and ditch the regulator?

Thanks!
Joe W.

RE: JR HV Servos
 

You really need to ditch everything and just use HV servos. On the lower voltage they will work, but not as well as they do on the higher voltage.

RE: JR HV Servos
 

Cool. Thanks Tony.

RE: JR HV Servos
 

There are ways you could do this if you wanted to bad enough to build some custom cables.

Jim

RE: JR HV Servos
 

Also Spektrum sells a small voltage regulator that was more commonly used in helicopters. It is the Spektrum VR5203 Dual Output Regulator. You can plug up to two servos in it and get 5.2volts regulated. It's about $30.

RE: JR HV Servos
 

Joe:
You can run most standard digital servos up to around 6.5V without a problem. In particular, JR digitals hold up just fine on regulated supplies in that range. You could set up a mixed standard / HVsystem that picks that as a compromise setting. The nice thing about regulating LiPo packs, even for an HVservo, is that you get the same performance in terms of speed and torque output throughout the usable discharge curve of the battery pack. It's really no different than what we did with 5 cell NiCad or NiMh packs a few years back, except that now the performance curve has shifted higher. Even if you go all HV, getting a regulated setup that is set somewhere around 7.5V, or slightly higher will give you that kind of consistent, high performance. There's something to be said for simplicity, but there is even more to be said for a setup that protects you against switch and battery failures.

Tony, I know this is an older tread, which servos are you running these day? and are you still unregulated?

In my Nuance and Episode I'm using 9411HV's on ailerons, 3711HV's on elevators. I have been using the 8911HV on rudder but JR has come out with an 8411HV so I am just trying that on rudder. Still not using a regulator.

Ok this was pretty much my choices....may I ask why switch to the 8411HV there's very little weight differences and its a little slower?

I see that you when to the 9411HV on the ailerons were the 3711HV as good for less weight?

I think the 9411's are a better choice for ailerons on a monoplane. 3711's might work well on a biplane. The 8911 is overkill from a torque standpoint and I've always liked the feel of the 8411 servo. I am trying it for the first time today and I will see if it will work for me.

Thank you for the quick reply...have fun, and please let me know :))

8411HV works just like normal 8411SA that we have been using.

I have 9411HV, 3711HV in my Mystic including the 8911 like Tony used. Yes 8911 totally is an overkill.

you will not be disappointed with these servos. I just replaced 3711 gears to 3121 plastic gears (total of 6 grams drop from both stabs).

thinking about changing gears on the 9411HV also.

I have about 20 flights now on the 8411HV on the rudder. I am very satisfied with it. I didn't change the gears and they are plenty tight. The feel of the rudder is, IMO, better then with the 8911. I'm quite happy with it.

I did notice one thing with the 3711HV servos on the elevators. While changing the rudder I noticed that when I was in my spin condition, which has a lot of elevator throw, if I went to full stick then just released the stick, occasionally one of the servos would overshoot the center then return. Both of them would do it from time to time. These servos are original with the model and have 450 flights on them. I replaced them with two servos that had new pots and gears installed and this issue disappeared. The model now feels much better. So keep an eye on the 3711's when your flight total starts to get high.

Well guys thank's a lots, I will get the 8411HV for the rudder and the 3711HV for the elevators, yesterday I couldn't resist with the price on the MP91T and got those for the ailerons hopefully it won't turn out to be a mistake will......the spec are good....much better then the servo I used back in 2000'ish when I flew pattern (any RC for that matter :) ) with the PLProd models...