extra 300

My Feedback: (3)

I am about to receive my Futaba MZ 18 radio and would like to install an S-Bus system in 2 jets that I already own:
A- Feibao F-15E 1/7 scale
B- Skymaster large Viperjet (2.5 meter wingspan).

I have (and still) read about S-Bus installations but I am still extremely puzzled about what exactly should I buy to accomplish required setups and have a lot of questions regarding S-Bus:

I presently do not have S-Bus servos but have High end JR and Hitech servos which understand can be used in S-Bus installation:
1- Please advise in details what exactly do I need to purchase to install non S-bus servos (programming, installing etc...)
2- how can I simply decide the layout of each jet to know exactly what material do I need to purchase (at one time) without having to go into trial and error process...
3- Can a normal extension be used if for some reason same is needed or extension has to be "S-Bus compatible"??
4- Any information you can provide to guide me through this venture would be appreciated.

As regards, to S- Bus servos, I have noticed (and wonder why) new S-Bus servos are popping up and many others are discontinued which reluctantly prevents me from going this way besides the fact that performing S-BUS servos are highly priced compared to similar non S-Bus ones.
Any particular reason why should someone go for S-Bus servos in his installation?


Please excuse my ignorance in this specific field, although I have been flying model airplanes for more than 32 years, it seems that there are limits to mental capacities and maybe some deep teaching is needed to be able assimilate new technologies...

Thanks in advance,
Regards,

mick15

I would go with a Powerbox SRS, a Cockpit, Compettion or the new Royal/iGyro, then all your old servos will work.

m

Dave Wilshere

Powerbox will release there converter this week where std servos can be used on a full S-Bus system
(see the latest RCJI mag)

Dw

Chris Smith

My Feedback: (2)

Non S-Bus servos can be used with the decoder extensions. Each decoder has leads for 3 servos. The decoder is plugged into the S-bus at any hub. The decoder is programmed so that it knows what function is on which of the 3 leads. The decoder handles the serial communication thus allowing use of any digital or analog servo.

On the other hand, S-Bus servos are programmed individualy then plugged into the serial bus at any hub location.

The jet must have an S-bus receiver. Extensions, hubs, and s-bus servos are plugged into the s-bus which is all plugged into the receiver using the s-bus port. Non s-bus servos plug into a 3-lead decoder which is then plugged into the s-bus hub.

Chris

extra 300

My Feedback: (3)

Thanks guys for all the input. will be looking at the Powerbox SRS cockpit option but afraid that solution might be a bit expensive....

Dave,

would love to get some info on the Powerbox converter just in case...

Chris
Still need some info on points 2 and 3 of my original post, which somehow maybe difficult for you to explain in writing but any help in deciding where to start from would be much appreciated.

regards,

john4648

My Feedback: (24)

Without stirring a debate as to the practicality of S-Bus in its current configuration perhaps an analogy might help. S-Bus sends the data for all servos down a single conductor much like a freight train traveling down a track. If you want to get to the forth car (channel) in the train you have to break the train apart to get that car. Hence a switch yard. In a switch yard as the train is separated each car (channel) is sent down its correct path. Our current and familiar non S-Bus radio systems do the switching for us and each servos information (freight car) is sent to only the correct servo. On the other hand each S-Bus servo has to have the circuitry built in to pick off its information (like the switch yard). Slightly more complex than a standard servo (convert to more expensive). If you want a standard servo to work on S-Bus than you have to provide this circuitry to get your specific freight car (channel) of information off the track, called a decoder by Futaba. So an S-Bus servo works directly off the S-Bus line where as a non S-Bus servo requires a decoder to fuction on S-Bus.
Lets look at a normal wing. You probably have at least four servos two aileron and two flap. Futaba (Hobbico) in the USA sells a 3 channel decoder (Robbe in the rest of the world sells a four channel decoder). So in concept you would take 2 each 3 channel decoders (USA) and plug in/program them for your four servos (No Y harness here). Then you would plug the two decoders inputs into a terminal block in the wing. Then you could take one extension from the wing and plug that into the S-Bus of the fuselage and away you go very convenient and simple. If you had S-Bus servos in the wing you would take the four leads from the servos plug them into a terminal block in the wing then have one extension to connect to the fuselage. Again I do not wish to stir debate but the issue here is lack of redundancy and possible lack of sufficient power. If you have four servos in you wing and you plugged all four separately into your receiver theoretically you could loose one aileron connection and possibly retain control. Then the issue of power, a standard HD servo lead is 22 gauge and commonly we think of the servo connectors (the real weak link) as being able to handle about 4 amps when new and of high quality. We generally install servos with torque capability of a larger amount translate this to more current draw. Stall current of some of the high torque servos can be at the limit of what our little servo connectors can handle. Now multiply that current by 4 (your wing servos) and try to pull that through one extension (two connectors) and you begin to see the issue. a Battery could be installed in the wing or other measures taken to improve power delivery and redundancy. But then the system is no longer simple is it?
Futaba is to be commended for its forward thinking. It is up to us as users to incorporate or not based on our needs/uses. I own Futaba radios including the 14MZ and the 18MZ and use some of the S-bus on both a Nano and a Flash. S-Bus is not for everyone or every application. It is not a panacea. Power boxes are nice and have their purpose, remember there is a large component count increase in an added system like a power box, more components more chance of failure.
Gosh, hope this helps more than it confuses!
John

DrScoles

My Feedback: (18)

OP, if you already have the jets wired for regular servos, I don't see any benefit to using sbus receivers. I have three planes wired for sbus now, I love how clean the installs are. I have a warbird with four servos in the wing, one wire coming out to connect into the fuse... pretty cool.

But using the decoders everywhere just to run a few less wires and having to re-wire... total PIA IMO.

The powerbox option puzzles me, sbus is meant to reduce components and wiring, not increase it. I think jet guys really like to over do stuff

My only complaint is the lack of clarity with powering multiple servos with multiple packs. "Just plug a pack into the hub and it will power those servos." But it still works if I only have one pack plugged in anywere...

I did buy the new powerbox SRS with the igyro and sequencer for a big plane, but primarily for the gyro and sequencer. Then I find out the sbus extensions aren't available for it. Not a big deal, I'm a ways from using it.

schroedm

My Feedback: (1)

Good explanation John.

I know it's probably wishful thinking but I really want to believe Futaba know that their new hi-power servos are able to pull 'X' amps and thus their 4 port connectors should be able to handle 4 x 'X' amps.............

For me right now, the ultimate setup is a Powerbox SRS unit and keeping the regular hi end servos many of us have.

FenderBean

I know every goes to the powerbox stuff but they really don't use the sbus system like it was intended. If I were I would take a look at the the Robbe/futaba sbus system. Super easy and it support s both sbus and non-sbus servos like the others.

dbsonic

My Feedback: (3)

Agreed if the airplane is already wired and equipped with servos go with a Fut r6014 and save sbus for another jet.

ww2birds

My Feedback: (14)

Good comments so far, especially about power consumption by servos, wire sizes, etc.

It always seemed to me that the main folks interested in S-Bus would be the Jet community and the guys who build large 3D aerobatic planes, because if offers a potentially much simpler install when you have a lot of channels, a lot of servos, or both.. simpler still if you incorporate telemetry.

But if these are the target communities for the product, then I think the US-based product offerings are not really sensible .. using skinny wires and standard connectors. Most people who build large 3D planes and Jets go for much more robust wiring and power distribution, mostly for good reasons.

The best answer I have seen is the Robbe/Futaba PSS 2018 ([link=http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=article&ProdNr=RF1660&t=2378&c=2404&p=2404]http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=article&ProdNr=RF1660&t=2378&c=2404&p=2404[/link]). It has in my opinion the best set of connectors, wiring and power management for Futaba S-Bus systems. I have purchased via Emcotec, along with the requisite accessories and am installing in a Skymaster F-4 and an UltraBandit. I wish the US distributor would wake up and offer something like this here. I have offered this feedback to them directly as have others .. hopefully they will listen.

The Powerbox guys also have some nice products and are embracing all the bussed systems, which includes almost all major radio mfrs now, including JR whose satellite connection wires are essentially S-bus functions (the digital bitstream not demultiplexed).

I have retrofit one existing plane to S-Bus and the 7008 receiver so I could use telemetry .. it's the large Skymaster Viperjet and I used the iGyro .. so the conversion from S-Bus to conventional servos comes "for free" with the iGyro for 2X Aileron, 2X elevator and 1X rudder (5 servos in all) and the 7 dedicated outputs on the RX (you lose the 8th channel on the RX in SBus mode) handled the rest .. so I didn't have to use any of the 1:3 SBus "splitters" .. it's a pretty clean install and working very well.

A "generic" Sbus upgrade, for example from a 6014HS receiver to the 7008 SBus receiver would need three of the 1:3 Sbus to conventional adapters, plus the 7 native channels of the 7008 to replace all 14 channels (using only two of the 1:3s would give you 13 channels, 2 of the 3 outputs on the third adapter would be wasted). The only reason I could see doing this is to get telemetry working in an existing airplane (that's why I did it) .. otherwise you are upgrading but with no improvement in actual function.

Dave

stevekott

I like to keep it simple and don't use any expander boxes or regulators. Usually two 2300 A123 Packs into the RX. One on a Y to the 7008SB and the other on a Y to the S.Bus2 port (doesn't really matter where as they all wind up in parallel). I use the 8 PWM outputs on the RX and any channels in excess of that I use the Futaba S.Bus to PWM 3 channel converters. I don't have any S.Bus Servos.

Sometimes it's nice if you have a collection of servos in one area to use the PWM converters close to where the servos are and run the 3 wire extension to the RX. Robbe makes a 4 channel PWM converter and on the Flash I'm building I'll mount that in the wing (RtFlap, LtFlap, RtAil, LtAil) then I'll just have the one 3 wire connection to plug in when assembling the plane at the field. I'll go up a wire gage or two on the Red/Black wire just for insurance as I'll be powering 4 servos with one wire.

I've put together 7 jets so far with this setup and have never had a single glitch or hiccup.

mr_matt

My Feedback: (10)

Steve, you could run SBus as a ring network and if you set up the battery correctly you could tolerate a break in the bus wire, no?

stevekott

I think you could Matt, No problem. I have a slight concern with a ground looping wire acting like an antenna. But without High Current ESC's and we are not trying to transmit any video or anything like that the signals collected would be pretty negligable.

On that loop you can locate your batteries anywhere you would like. I like to put Shottky Diodes in series with my batteries to isolate them in the unlikely event a cell shorts out in one of the packs. I haven't seen that in A123's but it seemed pretty common in NiMh batteries. If you don't use a loop i guess it makes the most sense to put one battery on each end of the +/- bus.

Steve

dbsonic

My Feedback: (3)

the ring, I'm not picturing it. schematic/dwg?

But was thinking the 7008 has some interesting versatility with the channel modes and also the possibility to get a dual sbus going for distribution to avoid the "single point of failure" complaints often heard. I believe that requires using 2 of these.

extra 300

My Feedback: (3)

Thank you all for sharing your thoughts but frankly speaking for an S-Bus novice point of view it is getting more complicated.... seeing the various alternatives!!!

I liked stevekott approach which sounded fairly easy and would like if possible to elaborate on:
Going into details for the various functions how would you start your install and choose the layout and components needed if using non S-BUS servos (for the SM large Viperjet and The FB F-15E 1/7 scale)?
Can you still use standard servo extensions if needed to reach a hub or a decoder?

I know that at some point it will all start to make sense and be less confusing. The hole idea is to achieve a simple layout and reliable system... Hope I will be able to figure it all out soon.

Thanks

Regards,
Dany

ww2birds

My Feedback: (14)

Dany,

I did set up a Skymaster T-38 just they way you and Steve are describing. It is a smaller, lighter jet so this seemed like a sensible approach. I used all stock S-bus gear from the usual suppliers (Tower Hobbies here in the USA), and dual A123 packs each with its own switch, and both switches feeding the RX directly. No buffers, powerboxes, etc. Worked out very nicely from an install point of view. I did use heavy (but "stock") servo extensions to take the one SBus line to the tail to feed the two elevators and the rudder via a 1:3 splitter, and it is nice to only use 1 wire per wing with a 1:3 splitter feeding the aileron and flap servos. Used all standard (not SBus servos). Caveat .. the plane is pretty much done but not yet flown :-) Sounds like Steve(kott) has many planes done and flown this way, so I'd rely on his experience.

Dave

stevekott

You can use Std extensions to go to the hub or decoder. The decoders usually have pretty long extension wires built in different lengths and the signal wire is shielded (small advantage) so you might not need extensions.

Like I said earlier I've never actually used an S-Bus servo. Most of the planes I've done already had JR Servos in them or I had other non S-bus servos to use. You can serve 3 non S-Bus servos per decoder and 8 direct from the Rx so I just never felt a need or desire to use S-Bus servos. I'm sure they are great servos but I just never used them.

You can also ignore all the stuff in the manual about using channel 8 for S-bus (unless you are using the older S-Bus servos). Just use the S-Bus.2 port on the bottom of the Rx to plug the decoders into. You can also use a hub or "Y" to plug any telemetry sensors into the same port.

I wouldn't worry too much about over-current on the wires or connectors. While it is true they are only rated for 3 or 4 amps that is a constant 3 or 4 amps. Some of the real heavy duty servos can hit that at full load but it will usually be for an instant. Flaps may be an exception as the forces do remain constant. I had a flap servo mechanicaly jam once and it cooked the electronics inside the servo like a smelly charcoal briquette but caused no damage to the std servo wire and connectors.

The whole S-Bus thing really isn't much different than any other install other than channels 9-18 are handled with decoders.

Happy Flying,

Steve

dbsonic

My Feedback: (3)

I thought sbus2 port was only for telemetry sensors that signal back for the downlink?
You are saying it can be used to drive servos just like the regular sbus port?

stevekott

Yes I guess there is an S-Bus and an S-bus.2 type of communication. Telemetry sensors need the S-Bus.2 type of communication. And the newer Futaba Servos are also S-Bus.2 communications. The 3 channel decoder I know also works on the S-Bus.2

There is some VERY confusing language in the R7008SB manual that makes it look like channel 8 is for S-Bus servo usage and you have to configure the Rx mode for that and that the S-Bus.2 port is only for Telemetry. That is not the case as I see it..

I think the manual was written early on when the Futaba Servos would not communicate with the new protocol (S-Bus vs S-Bus.2) Most of the Newer Futaba S-Bus servos mention they use the S-Bus.2 protocol.

In ALL of the installations I've done I have never set up channel 8 as an S-Bus port and I have hubbed all of the decoders and telemetry devices to the S-Bus.2 port. A year and a half later and 200+ flights with NO radio problems. (knock on some wood)

Happy Flying!,

Steve

afterburner

My Feedback: (18)

Some good info in this thread. Like others have said, there really is no reason to retrofit an existing setup unless you want telemetry. While I was putting together a Carf Hawk, I purchased an 18MZ and even though I was initially going to use a 6014 RX in it, I knew I would eventually switch it out so I could get telemetry so I used three sbus mini servos for gear and brakes(two gear valves to have scale gear doors on the Hawk/T-45). They were used as normal servos with the 6014 and then hooked up to the serial bus when I switched out the RX. All flight surfaces were put on the PWM outputs of the 7008. I should also mention I'm using a SmartFly power expander pro in this setup. Since the SmartFly regulates logic power to the Rx to 5V/1 amp max, I tapped the servo power bus off the SmartFly and fed it to the sbus servos since they couldn't be directly hooked up to the SmarFly. The nice thing about the sbus servos is being able to program many different variables like dead band which is helpful especially for controlling air valves.

Marty

extra 300

My Feedback: (3)

Steve,

Below is a layout of the large FB F-15E that I would like to wire using S-Bus. could you please help figure out how many decoders cables would I eventually need? as well as hubs etc...
Presume that from a 3 output decoder cable running from one side (L or R) from the back I would connect elevator and rudder and leave the 3rd socket free??? or should it be done differently?

Thanks in advance,

Regards,
Dany

extra 300

My Feedback: (3)

A small additional note. Landing gear has been converted to electric. Airbrake and cockpit will also follow same trend. As for gear doors have not yet figured out a simple way to convert them to electric and might end up keeping them air actuated along with brakes....

Regards,
Dany

myersflyers

My Feedback: (33)

Dany,
You could use something like JR3421 or Fut3156 servos for doors and program your 18 using slow (close) and fast (open) speeds to sync with the gear going up and down. Easy to setup and get timing between gear and doors just right.
Rgds,
Keith

extra 300

My Feedback: (3)

Keith,

Thanks for below. Correct please if I am wrong, I would have to connect servos/doors that move the same way together accordingly I would be using 2 or 3 channels out of existing 18 correct?

Regards,
Dany