kylenlord

I was reading over the latest tower talk, and went to look under the specifications of some of the futaba digitals. Under the first few of them it said the output, then in parenthesis, 4.8 only. I assume this means that you're not supposed to use a 6.0 volt receiver battery with these servos. I just purchased a few digital Hitec HS-5645MG Torque Metal Gear Servos, will it be alright to run a 6.0 volt battery for these?
Thanks,
Kyle

RCPilot100

My Feedback: (4)

Kyle,

Several of my friends are using Hitec digital servos in their 3D birds and both are using 6 volts. Kris has been flying his FiberClassics for three years now with no problems - Larry has the same all this season. As for Futaba digitals, I read an AM posting talking about the fact that their gyros can't take 6 volts - and that the servos that are used with them are listed at 4.8 volts so the gyro isn't over voltaged. Forget the gyro and 6 volts is ok. The question came up because someone checked the specs at ServoCity.com and noticed the 6 volts specs listed for the Futaba digitals. So, when I finish my Edge, I have Futaba servos that will be on 6 volts.

Dan

bpryor

My Feedback: (45)

Hi Kyle,
Absolutely. They are designed for 6v and work great at that voltage. I can't imagine any reason to run them at 4.8v....unless of course you had something else running off the same battery that couldn't handle over 4.8v...but then the best thing to do would be to put a regulator inline with that component(such as the above mentioned gyro) and keep the rest running at 6v.

edge_fanatic

My Feedback: (4)

Mike Mayberry (the hitec rep) tells us that 5-cell nicad packs are fine. Remember that we are talking about a pack that peaks at over 7.0v.

However, Mike recommends that folks run these systems unregulated, due to the current limiting effect of the regulator. Thus, using a regulator in effect starves the servo of needed battery power.
I run 5945's right now, and they seem to be doing fine unregulated on a 5-cell pack.

The only aircraft item I can think of that runs only on 4-cell packs is Heli gyros.

Cheers,

Sean

bpryor

My Feedback: (45)

Hi Sean,
I agree completely with you Sean. Just to make sure I was clear, and nobody else misunderstood my statement, I was only suggesting you run a regulator on the one component that was limited to 4.8v. All the servos would still run on unregulated 5 cell output.
This is actually not the case. All that will happen is the servo will run a little slower, and will be a little less powerful. The servos do not "need" 6v, it is just desirable for the obvious benefits. The benefit of running a servo on 4.8v is that it will last longer, though probably not enough to matter for most people.

edge_fanatic

My Feedback: (4)

Hey Bill,

You actually brought out a point I hadn't considered, and that is the use of a regulator for 4.8v, rather than 6.0v....heh

I had been thinking in the 6.0v mode....my mistake.

I agree with your description of the effects of a regulator being slight speed degradation and torque degradation...

Cheers!

MikeMayberry

My Feedback: (1)

bpryor- Most regulator limit the current not just the voltage; that is why you should not use them with the digital servos. The digitals will work fine on an unregulated 4 or 5 cell pack but there can be problems when using a regulator because of lack of available amperage.

For example... you cannot use alkaline batteries to run Hitec digital servos. Even though there is plenty of voltage, there is no amperage.

Mike.

bpryor

My Feedback: (45)

Hi Mike,

Thanks for the info. You say "most" regulators limit current, does that mean that some don't? Do you know which ones don't?

Bill