Futaba SBus Questions

[HRRC Flyer]

I realize I should have asked these questions here and I hope @Bartman doesn't mind me asking the same questions in more than one place, but I have a few questions about SBus. My first set of questions are as follows;

1. Since my Laser has four servos in the tail, what is the best way to set it up? Will I need a 6-way terminal block or will the 4-way work?
   
   
2. Should I be concerned with the power consumption of running four HV servos off one Sbus cable from the receiver?
   
   
3. Is there any difference between an SBus extension and a regular servo extension?
   
   
4. Does Futaba make the cables that go between the receiver and the terminal block longer than 13" (350mm)? I saw the 1 meter cable that goes from the SBus port in the receiver to a three way plug, but not one that can plug into a 4-way or 6-way terminal block.

I am sure I will have more questions, but this is a good start.

Thanks Fellas,
David

 

[Dan767]

What I have done: A short female to female cable from the receiver to the 6 way block. For the tail servos, use two of the short sBus extensions and two heavy gauge extensions routed to the tail, unless the longer extensions will reach the tail with out them. The SBus receiver is connected to the 6 way block using the end connector, makes it easier to connect. Keep the lead form the receiver to the six way block as short as possible, I use them on my 42% PAU Extra. I prefer to use a heavier gauge extension then add the shorter gauge sBus cable when making long runs (More than the 1 meter extension).
There is no difference between the sBus and regular extensions, just the ability to plug three servos in.
I am running two receivers and 13 HV servos on the Sbus system, higher voltage requires less current draw so the use of smaller gauge wire is possible.

Hope this helps,

Dan

 

[Judge]

There is nothing special about the S.Bus blocks/connectors. They are electrically the same as a "Y". So you could make up your own pigtails if you want.

 

[HRRC Flyer]

@Dan767 & @Judge, Thanks for the quick response. I really appreciate it. . . .

Please read the following and tell me what you think.

1. Install a short female to female SBus cable from the receiver to a 4-way block.
2. From the 4-way block, run a 3 into 1 end connector up to the front of the plane. One port for the throttle servo, one port for the choke servo and 1 port with an adapter for non-Sbus devices for the ignition kill switch. This leads to another question, how do you program the adapter to a specific channel?
3. Even though my Laser is a kit built 1/3 scale Lanier, I'm fairly sure that the receiver battery will be back near the receiver since the original owner flew the plane with a DLE61 and I'm using a 3W70. Therefore, I'm planning on plugging the battery directly into the receiver.
4. Plug the ailerons directly into the receiver as well.
5. This is where I am unsure which way to go. Since I have four servos in the tail, I would like to use a long female to female cable from the four way block at the receiver to a six way block near the tail and plug the two elevator servos and the two rudder servos into the block. My reasoning is that if I still need to move the receiver battery further back, I can do so and plug it into the block in the tail.

So, what do you think?


Thanks again,
David

 

[Dan767]

David,

I would run an extension from the kill switch back to the receiver, this keeps that part simple.
The 4 way block at the receiver sounds good, I believe the Laser has four aileron servos. As long as you have a way of getting to the 6 way block in the tail, that's great. Another option would be to put a 6 way block at the receiver, and plug all of it into the 6 way, even the extension going to the tail.

Regards,

Dan

 

[HRRC Flyer]

Dan,

I like your idea about running the kill switch back to the receiver, it is allot simpler that way.

I think with the location of the servos in the tail (they are all right in front of the leading edge of the stab) and the length of the servo leads, I should be able to reach in through the turtle deck on the fuse to access the 6-way block. If not, I don't mind pitting a hatch on the bottom of the fuse. Besides, if I have to move the battery back there for balance, I will need access to it for removal and charging.

Speaking of batteries, do you think a 2800 mAh LiFe battery is enough for the receiver only? I have 6 HV servos and 2 additional servos going in the plane.

I'd love to have a monster PAU like yours, but I'd have a hard time fitting it in my Durango. . . . . .

Thanks again for all your help Dan, I really appreciate it.
David

 

[Dan767]

David,

It would be better to use a larger battery. If you can do it, Taildragger RC or your preferred source of batteries, I personally would use something near 5000mAh. As long as you know the orientation of the plugs going into the block, behind the turtle deck is fine.

I don't own a trailer, I take the stabs off, and gingerly weave the rudder through the overhead entertainment center of my 2005 Explorer.

Let's figure a way to get one into your Durango next

 

[HRRC Flyer]

5000 mAh it will be. I happen to have an extra Duraflight in that size too.

Your last comment cracked me up. I am getting ready to build my 50cc AMR Stick and I'm going to have to make the horizontal stab of that plane removable if I want to get it in the back of my Durango. Besides, I was joking with a friend of mine about the way his hands shake from nerves when he is doing maiden flights. I told him my hands never shake with my maidens, but when I did the maiden on my scratch built Kaos, my heart pounded so hard it feels like it will come out of my chest. If I had to maiden a 40% bird, I'm afraid I'd have a coronary right there on the flight line. . . . .

 

[Dan767]

Bigger flies better/easier. You can do it!

 

[AKNick]

Maybe someone can help me figure this out. Can you use any programmable servo for SBUS or do they have to be SBUS servos?
Here is what I am thinking about doing:
Futaba R6208SB is running out of channels to plug into. I'm curious if I can program two HS-7955TG (all surfaces using this servo), one for each elevator our of the SBUS port using a hub or Y so I can free up a port or two. I have zero SBUS experience.
Current Channel Inputs
1-Ail1
2-Elev1
3-Thr
4-Rudd
5-Elev2
6-Ail2
7-Opt Kill
8-Batt
SBUS - ??? would like to add a channel for a TME/Powerbox smoke input

Thanks!