RunRyder RC
 10  Topic Subscribe
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 510 views POST REPLY
HelicopterRadio - Futaba FASST › Futaba R6014FS Receiver Voltage?
05-13-2018 03:46 AM  8 days agoPost 21
rcscaleguy

rrNovice

CA, USA

My Posts: All  Forum  Topic

Futaba R6014HS 14-Channel FASST Receiver

Just a note, being your trying to run more voltage but you are not using the 6014HS which enable the use of High-Speed Servos functioning at there peak performance. So before going up on voltage why not take advantage of all of a digitals servos ability before trying to pump up its power instead of pumping up its precision.

Nice plane by the way.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-13-2018 01:41 PM  8 days agoPost 22
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

I suppose I could have posted this earlier to give some structure to the original question...

I've been making my own flight battery packs for a number of years now. I have really learned to like LiIon batteries for a large number of reasons. Some qualities I like about them are:
- They are sturdy.
- Near zero self discharge. All of my models are always flight ready.
- Tolerate being stored fully charged. No need to put 'em in storage.
- Compact and powerful. 3,400 mah and 4.2 volts.
- Affordable. About $8 a cell.
- Readily available.
- I get the prettiest, most repeatable, battery performance graphs of any battery I've tested. 5 years from now I get almost the same graphs.

In short, for about $20 I can build the battery pack I've been looking for for decades.

Having built the battery pack I seek, I have a compact and reliable 8.4 volt flight battery.

Convenient for me is that R/C equipment manufacturers now make servos and receivers that will accept this battery with no further technology required. Servos, receiver, battery and done -simple. While voltage regulators have come a long way, I'd like to avoid cluttering this elegant battery solution with more electronics and connectors. I'd like to avoid the conversation about regulator current capacity, cooling, etc. With HV battery, servos, and receiver there is no reason for discussion - just plug it all together.

If anyone needed more reason consider this solution, servo performance only improves with HV input.

Obviously none of this post is required for this thread but it may give a reason for it. As I said in post #1, I have some older receivers that are too nice to be sitting in a plastic bag under my workbench and I'd like to get them airborne. Unfortunately they will not serve my purpose for this project.

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
05-14-2018 04:42 PM  6 days agoPost 23
JLF92677

rrApprentice

Southern California

My Posts: All  Forum  Topic

Bill, what is the C rating of the Li-ion cell you are using?

PM  EMAIL  GALLERY  Attn:RR  Quote
05-14-2018 05:56 PM  6 days agoPost 24
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

JLF92677
Bill, what is the C rating of the Li-ion cell you are using?
A very good question. Typically the C rating for Panasonic 18650 cells is 2C continuous. I've been using 3,400 mAh cells and feel comfortable pulling 6 amps from a 2 cell pack.

A more detailed discussion:
While this is largely a Futaba thread, a few of my helicopters use MKS X8 servos. I think the "X8" stands for 8 times the current draw. A set of 5 X8 servos in a FBL helicopter draws about 700 mAh from a pack in an 8 minute flight. I flew my Align 700XN three times yesterday and I put 2,100 mAh back in the pack. That calculates to an average amp draw of 5.25 amps.

Two things to note: First, 4 flights on a sunny day could use more than 2,800 mAh from a 3,400 mAh pack. There almost certainly would not be enough capacity for a 5th flight.

Second, while the average current draw is 5.25 amps, the peak draw will likely be well above that.

These two combined scares me.

If a particular helicopter setup appears to be approaching my personal current/capacity buffer zone, I put two packs in parallel. By doing so I up the capacity to 6,800 mAh and current draw is no longer an issue.

Of interest to this thread - All of my most valuable helicopters have FASSTest receivers and are linked to my 18MZ. With this setup I'm able to see real time receiver voltage. More than that, I'm able to pull up the minimum receiver voltage seen in a flight. Of course I can and do also set up a receiver low voltage alarm.

The last batteries I bought come from the link below. I have bought them from an assortment of places over the years. For R/C use I would not recommend "protected" cells.
https://www.ebay.com/itm/2925409506...em=292540950662

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
05-14-2018 10:12 PM  6 days agoPost 25
Heliguychris

rrKey Veteran

Perth, West Australia

My Posts: All  Forum  Topic

Hi there, i have been extremely reluctant to add to this thread, but i figure since no one else has chimed in from the other side of the coin, for balance let's throw my experience out there. I don't speak for anyone but myself.

With all due respect to Dr Ben, and the huge experience of the membership here, i don't wish to disagree with them, simply pass on my own experience. I would always respect anything that many of the members here would contribute.

That said. I have been using about half a dozen 6014HS rx's for nearly 10 years, in many models on Lipo voltage. I know of several others here and many others abroad who have as well, and i haven't heard a single example of a failure. When they first came out, no one could say for sure whether we could use lipo rx voltages with the early lipo voltage servos, so we just did. There may well have been failures of course that i don't know about, and in fact law of averages would say that there must be. All things fail eventually.

I use them primarily in jets and 40% planes as twin receiver setups. I'm big on redundancy for the really expensive stuff. I split my planes in half for all intents and purposes.
I have also used these rxs on helis as single setups, and on smaller 50cc planes without issue, for thousands of flights.

I also use the R617FS 7 channel fasst rx on lipo voltage. I have 3 of these that must be at least 10 years old by now, that have only ever run 2s lipos.

I only run HV servos now, but in the early days of HV setups, the choices were limited, and it was largely trial and error. Align 610s held up pretty good, as did some futaba servos.

When explaining my logic behind my thinking with HV setups, i would point out NIMH pack voltages.
A 4.8 volt nixx, fully charged off the charger is nearly 6 volts when you plug it into the rx.
A 6 volt NIMH is nearly 7.5 volts.
The engineers who developed these rxs must surely have know this and have it appears built in a suitable safety margin.
Futaba RX's work down to 3 volts after all, when most servos would of turned to mush long before.

Me personally, i would not run a single 6014 on lipo voltage on your pretty bipe. But i do wish you all the best with it, i bet it looks ace in the air!

Happy flying!

Licensed (CASA) UAV operator certificate holder 1-YFOF5-01 www.helicamaerial.com.au

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-14-2018 11:59 PM  6 days agoPost 26
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

Hey Chris...

I really appreciate your input and I don't find anything you said in contradiction to what Ben has contributed. Ben has contacted the people at Futaba and they have officially said they do not recommend unregulated LiXx batteries for the receiver in question. Certainly valid information and not to be taken lightly.

Equally valuable is your real-life experience suggesting that, while it may not be recommended, many people have been doing it for years without incident.

Both of these bits of information are something modelers can use.

I am holding at least 3 Futaba receivers that I know of that are rated for 6.0 volts. As my airplanes come due for new servos I've been replacing them with HV servos. Airplanes that are less valuable to me will still get HV servos but will get one of my R6014 receivers. Your comments make this a pretty easy choice.

Using the information provided by Ben -- For this Pitts, I will install the R7008SB HV FASSTest sitting here. I had been keeping that receiver for a project that could use its serial bus function but the Pitts is too important to me to take a chance.

Thanks... Thank you both.

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <     1     ( 2 )    >    >> ] 510 views POST REPLY
HelicopterRadio - Futaba FASST › Futaba R6014FS Receiver Voltage?
 Print TOPIC  Make Suggestion 

 10  Topic Subscribe

Monday, May 21 - 4:20 pm - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online