DrScoles

My Feedback: (18)

Love the technology, not sure about battery draw. Have a jet with 14 servos to flying surfaces, having a tough time finding info on current draw and when/where you need to put additional power.

Thanks

aussiesteve

I have 1 x 30%'er using the Robbe 4.1 hub and a 35%'er using the full blown hub (PSS 2018) and am currently building a 50%'er with 2 receivers and the PSS 2018 (our rules here state we must use 2 receivers on anything over 25kg).

The thing with S-bus is it allows you to get very creative n the placement of some major items.

The current draw you will experience is no greater than what you woulds have with any other system as the draw very much depends on the forces the servo needs to overcome. The minor amount used to power the electronics is more than made up for with the efficiency of the system. Some would argue that S-Bus uses less current than other systems but I have no information to prove or disprove that.

As for where to place power, any power source whether it is additional or the primary source, the answer is you can fit it anywhere you want to in the system. I am currently considering placing batteries in the wings of one of my planes and when I was considering placing a heavier enigne that the airframe was designed around, I considered placing the batteries in the horizontal stabs.

So, to answer your question
There is no great addition on power requirements for S-bus. Just choose the servos to suit the model, Get the programmer to program the servos and enjoy setting them up and the great resolution, power and centering from the S-Bus servos. (assuming you use the S-Bus servos).

DrScoles

My Feedback: (18)

This could be a cool way to balance a plane without worrying about long leads. Gonna order everything as soon as I get it mapped out. Too cool!

TimBle

Just ordered some S9072SB for a 25% Edge. Going to use it as an aexperiment in matching SBus servos' to non S_bus via the Rx and via the SBD-1 decoder cables.
Throughing the whole mish mash into one pot.

TimBle

Just ordered some S9072SB for a 25% Edge. Going to use it as an aexperiment in matching SBus servos' to non S_bus via the Rx and via the SBD-1 decoder cables.
Throughing the whole mish mash into one pot.

aussiesteve

Hey TimBle
Do yourself a favor and get the ciu2 USB interface (programmer). It gives you a LOT of programming options for the s-bus servos.

I was pretty sceptical about the S-Bus system at first which was why my first foray was into a 50cc "expendable" plane using the 4.1 hub. Many people here were coming up with al sorts of reasons why not to use it. Including being locked into a brand (I am anyway because I am unlikley to change to another brand of radio in a very long time), relying on one cable to provide the power (and it is properly sized - so it works very well) and the cost (it is in fact cheaper for a full s-bus setup than it is to buy similar top of the line servos, a good quality power board and a good quality receiver).

Let me know how you get on with your setup mate. I was pretty impressed when I started using it.

TimBle

will do, order placed with Tower. now the wait starts.
I ordered 5 off the S9072SB
1x of the Decoder cable for the choke and throttle servo's
1x 1000mm hub with extension cable
1 x 4 way extender block.
1x male to male hub to Rx connector

I am thinking the 2 elevator servo's and the rudder servo can plug into the 1000mm extension cable with hub.

The extender, the Decoder and the two aileron servos will plug into the 4 way connector block.

Dan767

My Feedback: (19)

I think I might embrace the technology and give it a try. I have a 50cc 3Dhobbyshop Extra that I think needs S Bus. I'll post when I finally get it up and running.

airbornrc

My Feedback: (9)

I just got done setting up a 33% pawnee. We used servo's already in the shop (non s-bus) for the tail and engine control, and put s-bus servos in the wings and glider release. So far I am very impressed. It all went together easily and at least on the bench works great. We admittedly have a very diverse mix of servos but it all seems to work well. I hope to have all the bits finished up in the next few weeks and will pass on our experiences.

Mark

TimBle

still waiting for tower shipment to arrive. Being Christmas season and based at the almost as far away from Tower as Never never land it does take a few weeks via insured parcel's... :/

TimBle

I maidened my 30cc GW Edge 540 yesterday. All I can say about the S-bus system is that it is FANTASTIC!!

wind junkie

My Feedback: (1)

From a redundancy standpoint, I don't understand why it's desireable to minimize the number of wires going from the RX to the servos in your giant scale airplane.

Yes, the SBUS system seems clever and creative, but I didn't think GS was the ideal scope for its usage.

TimBle

1. How often have you had a properly engaged plug connection disengage?
2. Do you have redundancy in a conventional Rx to servo set up?
3. if "YES" above, please explain how

aussiesteve

SBUS is a complete system.
On a complex model, such as many turbine models and the larger Giant scale models, where there are many servos in the tail. the mess of wires heading to the back become messy. The single (properly sized) cable makes for a neater (and usually better secured because of it) install. But that is not actually the main point behind SBUS, it is just a beneficial factor.

What the SBUS system provides is
Servo programmability

Simplicity (you can plug any servo into any wire and it will act according to the right signal for that servo). For example. On my larger planes (50% and 60% sized), I need to feed between 8 and 12 tail servos. I can plug any one into any connector and they reposnd properly.

Servo Accuracy - I am not any sort of electronics guru so my explanation here may be a little basic but - The elecronic "signalling, receiving" and procesing used in the system gives an amazingly good servo response, repeatability and accuracy. Even I can feel the difference on it despite my old shaky hands. (When compared to the previous systems used by me which were other digital servos through powerboards with the only connectors in the lines being where the leads connected to the powerboards). The repeatability of the servo functions is also pretty amazing.

Servo power - the SBus servos are certainly powerful.

System efficiency. My batteries lose less charge in a day of flying my SBus planes than they do in a day of flying my similar non SBUS planes. I have yet to fully quantify it but I know there is about 85% of the "MaH" used to put into the planes now after a day of flying.

Could all these and other features be incorporated into "non SBUS" style systems? Probably they could but the fact is that Futaba have built them into SBUS.

This is pretty much the same as when 2.4G came out. The features that we were all sold on could have also been built into a PCM style system (and in fact Multiplex did so with one of their systems) but the manufacturers didn't do that, they built the features into the 2.4G and look where that is now.

Would I use it on say a 26cc sport plane? - probably not. Would I use it on a top end F3a plane? - Yes definitley as the weight savings and the quality of the servos make it worth while (Using the 4.1 hub etc).

aussiesteve

A couple of times - about the same time the plane "disassembled itself" when boring a hole into the ground under power.


Yes - I can cause a crash with either my hands or my brain farts.

wind junkie

My Feedback: (1)

No, I've never had a GS servo disengage. There are many ways of securing connections which could also be used for SBUS servos. I'm mostly questioning the wisdom in minimizing control and power paths in heavy and expensive systems known to be hard on their equipment.

I like Don Apostolico's (of Don's Hobby Shop) approach to redundancy. Two RX's, two switches and two batteries independently acting as two separate systems, controlling wing and opposite elevator on each side, with rudder/throttle split as well.

Of course this could also be done with an SBUS system. But in general, on a GS plane (ie 50cc or larger) I'm not trying to minimize wire weight, nor control path redundancy which is what I believe to be the prime attraction for SBUS.

Also, an SBUS system means I need SBUS servos. That's another issue, but still considerable to those of us who already have favorite high dollar high power servos.

I'm not saying there is no ideal use for SBUS, I'm just saying it offers no advantage to me as a GS flyer over a simpler and arguably more reliable system.

TimBle

Nice summary.
also you can add that since each servo receives a coded signal down the single comms line, that signal is less prone to interference, further increasing reliability.
The advantage of plugging in servo's into a LAN is that you can never get it wrong unless you got it wrong to begin with.

The servo's are fantastic! The S9072SB is superbly fast and accurate. They're fast enough to really assist with precision movement. There's no hesitation thats no overshoot. These are rated at 10Kg on a 6V battery but they feel like 15Kg servo's (I suspect Futaba rate their servo's for the rated torque value at the rated speed whereas others may rate each independantly, artificially making the servo's seem better)

My next project is a Black Horse Stuka 1.20. Going with the R6203SB and a few SBD-1 cables with S3010 analogues. Again moe than likely overkill but the Rx + the SBD-1 cables work out only slightly more expensive than the R6014HS. I have like 10 or 11 servo's to control and I feel this is going to be the best way. If I use S-Bus servo's i would have real flexibility on my hands

aussiesteve

When I assembled my 50% Yak, I did a cost comparison. This plane uses 4 x Elevator servos, 6 x Aileron servos, 4 x Rudder servos, 1 x throttle servo, 1 x choke servo, 2 x optokills (twinspark engine) and 2 x receivers. I only mention the optokills and dual receivers as they are mandatory on models over 25kg here.

I don't have the exact figures in front of me but the entire setup cost me around $3200 for the electronics (plus the batteries).

The S-Bus sytem actually saved me just over $200 when compared to the other option which was a Smartfly powerboard and regulator with the multiple extensions and (whatever your favorite brand of) high torque servos is.

I am running 9075's in this plane so alternative servos would be 9157's 79xx's or whatever the JR equivalent number is (I don't remember it off the top of my head).

I have planes set up with both systems and both work fine. The savings on the S-Bus were largely to do with savings on the cost of the servos (for the power actually provided - get any of your favorite servos, place a weight at 1cm or 1" frmo the centre of the servo shaft and see just how much they do actually pull - you may be shocked to find how low it is in some). The lower cost of the receivers (S-Bus receivers are pretty much only using a few channels), the in built regulation and the reduced cost of servo extensions etc (you don't want to use crappy extensions in a plane like this).

Would there be a saving on a 50cc or 100cc sport flyer? I doubt the difference would be much but on the "target audience" planes, there are certainly savings.

As has been mentioned above in different ways, S-bus is not required on all planes but for precision and simplicity in more complex airframes, it is a good way to go.

Now if only I could get "S-Bus" on my thumbs, I would be doing ok.