miroker

Want to go with 6 volt BEC to get better performance from servos. Tech at LHS told me the GY401 does not work well with 6 volts. Anyone here have any feedback on this?

jh4db536

My Feedback: (2)

401 works fine on 6v.

BarracudaHockey

My Feedback: (11)

Its some digital servos that have a problem. That being said, if its regulated voltage you probably won't be able to tell the difference in flight between 5.1 and 6 volts.

miroker

Asked Futaba about this and they replied with following:

1) CAN I USE A 6VOLT BATTERY PACK WITH MY GYRO?
No. Futaba gyros (such as the GY401, 501, etc) are not rated for 6V packs which, when peaked, put out as much as 7.2V. Always use 4-cell, 4.8V packs with Futaba gyros. If you must use 6V packs, be sure to use a regulator (Futaba does not offer one) to keep the maximum voltage to the gyro under 6.0.

I am using the 6 volt ParkBEC and am now wondering if I am damaging the gyro by using it. Does anyone know if it is regulated to output no more than 6.0v or less?

ultraviolet

Correct ......... A BEC provides a regulated 6 V output. Futaba told you not to use a 6 V ( 5 cell ) BATTERY !!!

Go Fly

miroker

Part of it is the fact that now after putting 10+ flights on heli with the 6v BEC, I am getting quite a bit of tail wag that was not there before. This makes me wonder if gyro is failing or could it be caused by other factors?

ultraviolet

Other factors........... gyro gain , too much servo throw, poorly trimmed tail, control rod binding,
output shaft dirty and dry causing the pitch slider to bind, etc. etc.

Whenever you troubleshoot a problem, check the basics first. Don't create problems that do not
exist.

Happy Flying !!

Nankin Hobby

Yep those are some common factors of the wag.....the gyros are fin to run off a 6V BEC system. Most BEC systems arent a true 6V alot these days are 5-5.5 or there abouts. I havent seen any trouble running any Futaba Gyro off a BEC at my store. My MX400 isnt having a troubles w/that setup either....so its ok to use the gyros this way.

miroker

Asked tech support at Dimension Engineering (maker of ParkBEC) and here is response:

> ParkBEC will put out 6.05 to 6.1V in the worst case scenario, so if the
> gyro's limit is 6.0V I wouldn't advise pushing it so close to the limit.
> Best regards,
> Hisham Sakr Dimension Engineering

So according to Hisham, not a good idea to use their 6v product with the GY401. I am waiting on response from Futaba regarding the 6.1V output and whether that would fry gyro.

ultraviolet

6.1V is perfect. You will not have problems until the voltage goes past 6.5v and probably
not until 7.0 V. The only thing a 6.0 BEC will effect is a SERVO that is rated for 4.8v.

RELAX !!!

Clean and lube the tailrotor output shaft and go fly !!

miroker

I ended up swapping out the JR servo I was using on tail with a HS-55 and now wag is gone. However, until I hear from Futaba regarding the 6.1v, I would not recommend using 6v with gyro. Electronics can be sensitive to excess voltage and given cost of $140, not willing to chance it.

I do notice some crud on the shaft though, so will take it apart and clean it. Silicon oil should work as lube?

miroker

Got reply from Futaba tech support regarding the use of ParkBEC 6v:

> Thank you for your recent e-mail.
> That is possible and we do not recommend using that with the GY401.
> Sincerely,
> John G.
> Product Support Lead Technician
> Futaba Programming Technician
> Great Planes Model Distributors
> www.realflight.com
> NO AUTORESPONDER

>>> <[email protected]> 7/3/2006 10:52:49 AM >>>
>> Additional update: Received reply from maker of the BEC I want to use:
>> ParkBEC will put out 6.05 to 6.1V in the worst case scenario, so if the
>> gyro's limit is 6.0V I wouldn't advise pushing it so close to the limit.

> Given that information, would the 6.1v cause gyro to fail?
> Regards,
> John

So it seems that using a ParkBEC 6v is not a good choice according to Dimension Engineering and Futaba. Oh well, it was a good idea while it lasted.

ultraviolet

miroker, A lot of people have been running 6 v regulated systems for many years
with 0 issues. Futaba rx 's and gyros ARE designed to handle it.

It obviously makes you very uncomfortable to run 6v , so I would suggest that you
go back to 4.8 v.

Go Fly !!

Billy Haynes

I've got 70+ flights so far with my Trex SE/401/Dimension Engineering ParkBEC 6v with out any problems.

NateSD

I have been using a 6Volt park BEC with my 401 as well. Around 40 flights and no issues, but this thread makes me nervous. I would hate to burn up $140.... Oh well, I like the response from the servos I get using 6v. What to do?????[&:]

miroker

I did get second reply from Hisham at Dimension saying he checked further and it should be okay to run the 6v with gyro, but Futaba says no. I went back to the 5v BEC and will live with that as I am not willing to chance frying the gyro. And to be honest, can you really tell the difference between 0.11 and 0.09 seconds? Somehow, I seriously doubt any human can.

Karyn

You're right, no human could tell the difference between .11 and .09 seconds, but your gyro can...

The faster you can make the TR servo work, the more solid your tail will be. A slow servo will allow the tail to overshoot when the gyro corrects the position, wag wag wag.


Seriously, don't worry about running a 401 at 6v. Futaba, Hitech and JR rate all their servos for 6v (except the realy micro servos like the HS50). Why would they build 6v servos if gyros can only run at 5v?

This is what the manual says... (copy/paste from .pdf)

• Control system:
Digital advanced PI (Proportional Integration) control
• Gyro sensor:
SMM (Silicon Micro Machine) system vibration gyro
• Operating voltage: +4 to +6VDC
• Operating temperature range: -10°C to +45°C
• Dimensions: 27 x 27 x 20mm
• Weight: 27g (including connector)
• Functions:
Gyro operation direction switch, DS mode switch, Control delay
trimmer, Limit trimmer, Remote gain control, AVCS/normal mode


Futaba clearly state the GY401 runs from 6v.

BarracudaHockey

My Feedback: (11)

Thats not true, many of the Futaba digital servo's are not rated for 6 volts, most notably the 9253 and 54 tail rotor servos.

The gyro won't have any problems with a regulated 6volts or even a 5 cell 6v pack. The problem is the servos. Digital servos have a narrow dead band to being with, thats why they chatter. The higher the voltage the lower the dead band, so as the voltage rises, the dead band narrows and the servos that arent rated for 6v chatter worse, wear faster and draw down the battery faster.

Also most of these warnings about 6v stem from the use of 5 cell packs that come off the charger at 7 volts.

Now all that being said, all you really need is 5.1 or 5.3 volts regulated, I doubt you would be able to tell the difference between running that and 6 volts and your equipment will last longer.

PlaneHeli

Was just looking at buying a Parkbec 6V. It will be with a Futaba GY401 gyro & S9650 Servo.

Servo is rated at 6V.

What is everyones experience with 6V with their GY401 Gyro.

Any failures / problems

Andrew McGregor

What was said above... you only have trouble with exceeding servo ratings.

The poster who was having trouble with an HS-55 after 40 flights at 6V is typical... he just wore out the tail servo working it harder than it was designed for. That's why people recommend digital tail servos... they're more capable of taking the constant motion a tail servo has to deal with. But not all digitals are rated for 6V, so keep that in mind.

PlaneHeli

Thanks again Andrew.

I assume you have a Trex.

Do you operate an external BEC. If so what voltage.

Also I asked on another thread. (Do you use the Align 35A ESC). What low voltage protection is built in to the Align ESC. Does it cut the motor power (or soft cut) the power to avoid over discharging the battery. If so what voltage does it cut off at (2.8V, 3V, 3.2V).

Ive read 3S Lipos should be set to 3.2V.

If the Align ESC does not have any low voltage protection I was looking at buying a Liposhield from Dimension Engineering. Soft cutoff at 3V.

Do I need one. I would prefer a cutoff rather than just limiting flight time. Too random.

Cheers.

Andrew McGregor

Yes, I have a T-Rex. I use a ParkBEC from Dimension.

Don't rely on ESC cutoff, you'll toast your packs quickly. The reason is the cutoff voltage is right at the 100% limit, and there's no margin at that point... it's just there to prevent the worst accidents. Instead, get an LED lipo alarm and set it for 10.0V, that's 3.33V/Cell. When it lights up, you know you can safely (but right away) come in and land, because you've got roughly a minute left. If you do that your packs will last a long time (I don't know how long, I haven't worn one out since I started using alarms).

PlaneHeli

Andrew,

LED Lipo alarm sounds perfect. Only found one LED and one alarm only on the web. (both in US) Did you buy from NZ. What one did you get and from where. Im heading back to NZ soon on holiday.

Are you using the 5V or 6V Parkbec.

Im thinking of bringing my Trex and radio gear back to NZ while on holiday. You dont need a radio licence anymore in NZ Ive read. Im wondering if customs will give me a hard time with the Futaba Tx. Are you required to get them tested before you buy in NZ or are They OK if theyre within the Hobby frequencies.
The country im living in now requires imported radios to be inspected before you can use them.

Would not bring it if NZ was the same.
I cant find any info on the internet that it would be a problem.

Cheers

Andrew McGregor

You should be OK with the TX if it's on an NZ legal frequency, it won't need testing... the list is here: http://nzmaa.org.nz/frequencies.asp Customs probably won't notice anyway, but you can get in a lot of trouble by transmitting on illegal frequencies.

As for the lipo alarm, EflierNZ makes them, you can buy them on trademe or rchelis.co.nz (and probably other places too).

Oh, and yes, I'm running a 6V BEC with a 401, HDS877 tail servo and JR micos on the swash, DX7 radio. Works just great.

PlaneHeli

Damn that was quick, id only just finished editing it and their was a reply

Thanks.

Im on channel 40.830 so its legal in NZ.

Thanks for the alarm info. Will buy one online and get it sent to my NZ address.

Cheers