Futaba USA

[Snoopy1]

Two Fromeco switches, two Fromeco 5200 mah batteries straight into a 14 channel receiver controlling 8 MKS 777's and a throttle servo or 8 Hitecs. No powerbox of any kind ever. But I don't fly aggressive 3D.

So from the Fromeco Switch you are probably feeding 2 or 3 JR plugs into the receiver. So what you are telling me is that the buss in that receiver is good enough to do job. Thanks good info.

 

[AKNick]

Ok how do you gentlemen power 100cc and up planes with a number of powerful servos, do you all use Smartfly or something like that.

I would think that two batteries with dual rx leads each would be enough to carry the current load and prevent voltage sagging.

This is a little off subject, but Im going to do it anyways:
If each JR plug can handle a 5A peak, do the math and that's 10amp peak per pack (with dual leads), so lets say a 20 amp peak combined (four leads two packs). Now each servo can draw up to 2A peak, so a 100cc has 8 servos under max load at the same time (rare) that's a 16amp peak load... okay now a 100cc engine burns at max rpm 800 mAh so less than one amp... so 17amps total now. . . okay add a smoke pump at full output is less than 2 amps, so now we are up to 19amps. To sum this up... everything the planes' got under 20AMPS max load, four plugs going into an Rx from two batteries can handle under 20AMPS peak. This also means that 4 inputs are used in the rx, nine servos+IBEC IGN+ smoke = 15 channels used.

The beauty of a powersafe Rx is that there is no runs of small gauge wire from the battery to choke down to the RX, so the voltage drop from resistance is next to none. AND you don't used up spare channels to feed power distribution. It would be nice if Futaba gets a chance to make a comeback with a true powersafe receiver. Consumer interest = consumer will buy. Like AJ said he doesn't like carbon all over the interior of an aircraft because of the extra weight, but did it anyway (more sparsely though) because that's what the consumer wanted. Futaba should be no different even though what they have works. Need to compete in order to have competition. (and competition is getting better/upping there game!!)

Now a very hungry servo that has a long servo lead, should have a larger gauge wire, and possibly a signal booster, remote battery, or glitch buster. . . none of which I've used.

If possible you can eliminate the switch and use a quality connector like and EC2/3/5, XT30/60, deans, and Anderson power pole instead to a Y-Harness JR plug 18-20AWG.

Futaba's take on servo draw on the Q&A page:
Can you tell me what the maximum stalled current is on (insert name here) servo is?
Stalled current is going to vary depending on many conditions, but a basic approximation is:
Hi Torque servos= 1.6 amps

Here is an excellent article on JR connectors and current draw.
http://www.hansenhobbies.com/products/connectors/Connectors.pdf

One thing that always gets overlooked as well is battery internal resistance. lower the IR number = lower the voltage sag. Batteries tend to gain IR over time and cycles, which is why they should be replaced to some frequency depending on the chemistry. If not, you can get voltage sag followed by a brief loss of connection.

As you can see there are many things that come into play here. My thoughts on not using a smart fly or power safe on a 100cc are as stated above in my first line as an educated guess.

Sorry for the off subject, but I find this interesting!

 

[Snoopy1]

I would think that two batteries with dual rx leads each would be enough to carry the current load and prevent voltage sagging.

This is a little off subject, but Im going to do it anyways:
If each JR plug can handle a 5A peak, do the math and that's 10amp peak per pack (with dual leads), so lets say a 20 amp peak combined (four leads two packs). Now each servo can draw up to 2A peak, so a 100cc has 8 servos under max load at the same time (rare) that's a 16amp peak load... okay now a 100cc engine burns at max rpm 800 mAh so less than one amp... so 17amps total now. . . okay add a smoke pump at full output is less than 2 amps, so now we are up to 19amps. To sum this up... everything the planes' got under 20AMPS max load, four plugs going into an Rx from two batteries can handle under 20AMPS peak. This also means that 4 inputs are used in the rx, nine servos+IBEC IGN+ smoke = 15 channels used.

The beauty of a powersafe Rx is that there is no runs of small gauge wire from the battery to choke down to the RX, so the voltage drop from resistance is next to none. AND you don't used up spare channels to feed power distribution. It would be nice if Futaba gets a chance to make a comeback with a true powersafe receiver. Consumer interest = consumer will buy. Like AJ said he doesn't like carbon all over the interior of an aircraft because of the extra weight, but did it anyway (more sparsely though) because that's what the consumer wanted. Futaba should be no different even though what they have works. Need to compete in order to have competition. (and competition is getting better/upping there game!!)

Now a very hungry servo that has a long servo lead, should have a larger gauge wire, and possibly a signal booster, remote battery, or glitch buster. . . none of which I've used.

If possible you can eliminate the switch and use a quality connector like and EC2/3/5, XT30/60, deans, and Anderson power pole instead to a Y-Harness JR plug 18-20AWG.

Futaba's take on servo draw on the Q&A page:
Can you tell me what the maximum stalled current is on (insert name here) servo is?
Stalled current is going to vary depending on many conditions, but a basic approximation is:
Hi Torque servos= 1.6 amps

Here is an excellent article on JR connectors and current draw.
http://www.hansenhobbies.com/products/connectors/Connectors.pdf

One thing that always gets overlooked as well is battery internal resistance. lower the IR number = lower the voltage sag. Batteries tend to gain IR over time and cycles, which is why they should be replaced to some frequency depending on the chemistry. If not, you can get voltage sag followed by a brief loss of connection.

As you can see there are many things that come into play here. My thoughts on not using a smart fly or power safe on a 100cc are as stated above in my first line as an educated guess.

Sorry for the off subject, but I find this interesting!

Agree with all you said. And all the power distribution. But there is a but. Do not get me wrong like Futaba and still looking at it, look at the Jeti power receivers do not have a fail safe switch but do have power lead and plug to the receiver that is smart gets rid of all the little JR plugs that you have to sacrifice channels for power. That is simply to do why is Futaba so stubborn.

 

[acerc]

I like Futaba enough I just might order a T14SG or that T16SZ to go along with the T8FG and T7C. Ohhh Yeeaaa!!!

 

[Snoopy1]

I like Futaba enough I just might order a T14SG or that T16SZ to go along with the T8FG and T7C. Ohhh Yeeaaa!!!

Of all the ones you mentioned I really like the T16SZ If I get Futaba that would be my choice.

 

[acerc]

Of all the ones you mentioned I really like the T16SZ If I get Futaba that would be my choice.

It is a real nice radio, and despite what people say, I think the all black look's better than the imitation chrome.

 

[acerc]

It is a real nice radio, and despite what people say, I think the all black look's better than the imitation chrome.

My only hold back on the T16SZ is the 6.0v 1800mah NiMh battery, NiMh is out dated in my opinion.

 

[AKNick]

My only hold back on the T16SZ is the 6.0v 1800mah NiMh battery, NiMh is out dated in my opinion.

This was my main reason choosing the 18SZ, however... you can buy the 18SZ LiFe 6.6v 2100mAh battery for $90 (grossly overpriced) and program LiFe in the 16SZ, and to my knowledge only external charge it... I don't think you can buy the 18SZ charger and plug it into the 16SZ charge port. The 18SZ charger does not balance charge through the given charge port provided. Couple shortfalls IMO. So to buy the 16SZ with the 18SZ LiFe batt would cost a fellow $800, and maintain warranty... whereas the 18SZ is only $200 more at this point with a charger that works. Plug and play if I may.
I must also say the fake chrome is actually annoying, trying to look at the screen you can get blinded by a sunlight reflection. . .
My suggestion would be to get the 16SZ and buy the 18SZ LiFe battery, then use the extra $200 to buy an additional receiver.

 

[acerc]

That sounds very doable AK. There is something about the 18SZ I just don't like, might be the chrome. My T8FG upgraded is more than sufficient but need a back up, the 7C is only used for trainer and is short channels for most of my birds. If something happened to the T8 I would be shut down and with TG coming in a week I don't like the idea of being shut down.
Thanks for the battery info.

 

[acerc]

Of course I am very comfortable with the T8 so the T14SGA would be a direct replacement. And I could transfer all my models with an SD card, don't know if that is possible with the 16SZ. I don't use any mixing of any type so any of these radios are beyond what I need.

Decisions. decisions......

Forgot to mention, there is no where to get the 16SZ relatively soon but an hours drive away I can get the 14SG.