Guys,

I just got off the horn with Robert regarding one of the threads today regarding servos with the ability to handle 7 volts. The Hitec and new JR servos apparently can do so and in the case of the 5955 your looking a 400 oz plus with the 7 volt setup.

Assuming you were going to use a power expander system you could run your throttle servo directly off the RX so it sees only 5 volts ( thus a cheaper servo) while the rest of your beast runs on supercharged 7 volts.

Theres a catch of course and thats the cost to make these and the demand but how many of you would take it up if we could get say 50 or 100 of these built. They would run around about $130 a unit so its not chicken feed but man 400 plus out of your servos means two less on some ailerons so thats a $230 saving for a start.

Guys comment away please and hit the vote button if you have any firm convictions on this.

Kiwi

Well, let's see how much we really gain. Looking at Hitec's website and the specs for the 5995TG, which is the same as the 5955TG, except for a few nuances. The 5995TG and 5955TG are both listed with 333ozin on 6.0V. The 5995TG is listed with 416ozin on 7.5V (so has less than 400ozin on 7.0V). Assuming it's a linear relationship between voltage and torque, you are looking at gaining 27.67ozin if switching from 6.5V, which the Turbo Regulator is capable of supplying, to 7.0V from a $45.00 more expensive regulator.

I should be getting 361ozin from my 5955/5995TGs right now on 6.5-6.6V, does 27ozin more (388ozin) from each servo really justify running two in place of three, I doubt it.

Also, according to Hitec, the life expectancy from these servos go down considerably when running higher voltage to them.

The higher the voltage the shorter the life of a servo. The shorter the life of the servo the greater the chance of loosing a plane. I will stay below 6 volt, my 5955s give me lots of power now

Question: If hitec specified that the voltage for the 5955 is 7.4, does that mean that it can handle an unregulated 7.4v pack, or it has to be exactly 7.4v or lower?? usually when the servo is rated at 4.8, our pack will be running at around 5+, and for the 6v rating, our unregulated packs run around 6+ to 7. I have been using 6v pack unregulated with no problems so far on other servos, so am curious, anyone have some solid onfo on this?

I ran the 5955tgs on unregulated 2s Fromeco packs all last season. Still going strong, no problems to report. That's better than 8 v (8.4 IIRC) when they come off the charger. When I asked Hitec about it,
I was told that they will handle an unregulated pack just fine, but Hitec doesn't recommend it on aircraft because it shortens the life of the servo.

That said, I'm in the process of putting regulators in the plane and regulating them down to 6.2v in the interest of longevity.

MalaysianFlyer, Hitec does not list the 5955TG at anything but 6.0V. The reason is in the last paragraph of my previous post. Hitec does not advocate over 6.0V for the 5955TG due to reliability issues. If a robot servo (5995TG) quits, it doesn't fall out of the sky. And I have had two 5995TGs burn out on unregulated 2-cell LiIon, and others starting to act weird before regulating the voltage. And as I asked in the first post, is an extra 27ozin worth the trouble?

Wait a minute here. I just resently read a post, in another thread, where people are actually removing, or not installing the third servo into the main wing panel for the simple reason, of them not being needed, because two servos such as the HS-5955TG's can -more- than handle the work.

i would put the third servo in just for redundancy. it you have only two servos and one goes out, and then the aileron starts to flutter and you crash your plane that blows. i would like to have my 20 lb plane 6 oz heavier and be safe in case of a servo going out. IMO

Freddy, it all depends on the airplane, and what you mention IMHO is really not the issue here. What I see as being the issue is, that you can presently get 6.5-6.6V to the servos, is it worth the extra money to get 27 more ozin from each servo, as well as shortening their life?

mmmmm - i will stick with 6.5v!!! with almost two years of great service with 5955's - the extra umph no i dont need.

Ok I get the feeling but my use of the number 7 as being an exact voltage might have been erroneous, It could be 7.4 or as much as 7.6, thats just depends on what is wanted.

Again its just a rough survey to gage the feelings of you guys who fly big stuff with 7 plus volt capable servos.

For me 6.6 volts is plenty but there were a few other posts showing guys going direct to the Li-Ion packs and what my thoughts were is that is NOT TO GOOD. The initial voltage is easily as high as 8.4 and while it does not kill the servo you do get a huge difference in speed and torque as the packs discharge.

Keep it coming please everyone. If nothing else it helps us see what you want from products and what Bob may be able to do if the demand is sufficient.

KIWI

I dont understand why these companies keep antying up with the power. Do we really need those extra ounces of torque? Was talking with Dennis from Carden the other day and he was telling back in the day they were running servos that were comparable to the JR 4721 on all of there 40lb 40%er's. I dont even think that servo has 100oz's of torque. Unless you have a plane that is above the say 42, 44% level why would you run 3 servos? Is it necessary? With two servos on an aileron and one goes out chances are you probably wont know until you come down and possibly check it. Its not going to flutter off unless you are doing some 100mph high speed pass. How many of us do that now with our 40%er's. I sure as hell dont. Heck the wing is going to blow off before the servo goes out. I'll probably stick to my 8611's till the cows come home. I already have 600 oz's of torque on the ailerons why would I need 1200+ oz's of torque on them? Kinda idiotic because if they are rated at 7 volts you'll never get there unless they come out with a 7 volt regulator or just run it wide open straight to the battery and when or if they have already (havent heard about it) its going to be ridiculously expensive. I just dont understand all the extra power when all we have now is more than enough. Maybe someone else can shed some light on this subject.

Originally Posted by flybye

i would put the third servo in just for redundancy. it you have only two servos and one goes out, and then the aileron starts to flutter and you crash your plane that blows. i would like to have my 20 lb plane 6 oz heavier and be safe in case of a servo going out. IMO

That would be crazy to put 3 servos on a 20lb plane. Heck that 2nd servo you would put on a 20lb plane would be your safe guard for redundancy. People would say you are crazy if they saw 3 servos on a 20lb airplane.

I agree on that point, I have one servo per surface on my 23 pound plane (5955TG), and it's plenty. I can see 2, just for redundancy, but 3 makes no sense. And even 2, it's an odds game, you only have one on each elevator, do you think it's less likely to fail than the aileron servos?

A thought I had, smell the smoke, if you are regulating at 7-7.5V you limit battery capacity till the voltage drops to 7V and regulators dont work any longer