Alternative to multiple wing servo connectors

[Chris Bott - Moderator]

Who hates plugging in multiple servo leads when fixing a wing to a fus at the field?

We've seen mulipole connectors from Multiplex, Ashlok and even D Types. but what if we could just connect one servo extension.

Futaba's S.Bus system does indeed allow this, but expensive S.Bus servos have to be used. These are each set to a different S.Bus channel, then they are all connected to the same cable.

FrSky have a neat trick though, in the shape of a four channel S.Bus to normal servo, decoder. This little unit plugs into the S.Bus port of a suitable receiver, and gives us four standard servo outputs.

here's a pretty poor video too

[Stevo]

Why can't we have (what would equate to) a block of servo connectors connected together? Or some simple multipole connector? There must be some enterprising person out there who could do this?

I had a WOT4, with two aileron servos, one airbrake servo, and two separet wing lights (don't laugh).

I soldered them all into a 15w HD plug and socket. Took me ages, but the setup at the field was in seconds...

[Chris Bott - Moderator]

That was the whole point of the post Stevo, it's an alternative to all that soldering.

At about a tenner for the decoder, it can't be much more expensive than making up a plug and socket?

[Stevo]

Thanks for reminding me Chris.

This is the second post tonight that I've missed the point!! Is it an age thing? Should I be concerned?

 

But... I don't have S-Bus..

There must be a way to multiplex all that down one cable... (and don't say yes... S-Bus!)

But... did find this...

http://www.thunderboltrc.com/tboltharness/

Edited By Stevo on 20/03/2014 21:26:19

[Chris Bott - Moderator]

Posted by Stevo on 20/03/2014 21:19:15:

But... I don't have S-Bus...

There must be a way to multiplex all that down one cable... (and don't say yes... S-Bus!)

Edited By Stevo on 20/03/2014 21:23:45

This isn't very helpful if you don't have S.Bus - agreed!

Apparently it is compatible with Futaba S.Bus.
The unit will also decode CPPM if that's available.

Using all FrSky though, gives me an 8 Ch Rx for £23, then the £10 decoder can be set to respond to any four channels from 1 to 16. So I've set this one to be Chs 9,10,11 and 12.

PS, unfortunately it arrives with all 4 channels set to respond to Ch1. So an accompanying S.Bus servo - channel changer is a must, to set it up.

[Chris Bott - Moderator]

Those photos look extremely similar to Ashlok connectors, available from Fighter Aces which work well too, but need all the crimping doing.

[Stevo]

Yes they are ashlocks.. Ive tried crimping in the past even using different sets of crimpers with limited results. The purchased ones are so much better!

[Bob Cotsford]

One question Chris, can the decoders be connected through a Y lead or do they have to be cascaded? Eg for a two part wing with ailerons, flaps and retracts one sbus unit would be needed for each wing half but would another be needed to couple them to the receiver?

[Chris Bott - Moderator]

Hi Bob

They would be Y leaded. All 16 channels are coming out of the one S.Bus port.

Before installation, you choose which channel is fed to which decoder port using this as a once off programmer, much like an ESC programming card. Any Tx channel to any port, any order.

As I mentioned, you have to have a programmer or all 4 ports are Ch1.The programmer pretty much acts as a display and switches to set up the decoder.

Now I've worked it out, just holler if you need any help setting up.

[stu knowles]

Hi Chris,

Would you mind explaining this set up a little more and how it can be made to work using FRSky receivers

[PatMc]

Chris, does this mean the normal 8 servo ports can still be used, in effect turning the XR6 into a potential 12 channel Rx ? And if you used two decoders via a Y lead it's can be made a 16 channel Rx ?

[Chris Bott - Moderator]

Hi Stu

First the FrSky Rx has to have an S.Bus port. something like an X8R for example.
This port looks the same as a servo socket, i.e. 3 pins, but it carries all 16 channels. A normal servo can't be connected to it.

The original intent (possibly designed by Futaba) was to simplify wiring. S.Bus servos were required to use this. These also have to have their channel set before installation. Then, they are all wired back to the one port, the three wires to all servos connect to the same place, so the Y leads, (or hubs with multiple paralleled connections) can be placed where convenient.

This little decoder unit takes the 16 channel S.Bus signal, picks out 4 of the channels and provides those as normal servo outputs, so we can plug in normal servos.

The channels we program into them before installation can be ones that also appear on the usual Rx pins, or they can be extra ones. If they are to be extra ones, we need to set the Tx to send enough channels.

[Chris Bott - Moderator]

Posted by PatMc on 20/03/2014 22:40:50:

Chris, does this mean the normal 8 servo ports can still be used, in effect turning the XR6 into a potential 12 channel Rx ? And if you used two decoders via a Y lead it's can be made a 16 channel Rx ?

Absolutely PatMc.

XR6 can become a 10 Ch with one decoder, a 14 with 2.
X8R can become a 12 Ch with one decoder, a 16 with 2.

[PatMc]

Thank's Chris.

My typo BTW I meant X8R

[Chris Bott - Moderator]

Note: I only have one decoder, but can set ports to any of the 16 channels. So while I can't see any reason why two or more wouldn't work, as that's how S.Bus is intended, I haven't tried it.

[Depron Daz]

For multiple servo lead connections I use a 6s balance plug. All positives on red, all negatives on the next black and then up to 5 signal wires. However it still entails lots of soldering, but that isn't a problem

[Kevin Wilson]

On my current build I considered gluing all the servo connectors as they stand into one block making a single multi pole connector. I am sure it would work.

Instead decided to use a 9 pin D connector. But then I am very comfortable with soldering.

Interesting seeing a balance plug being used. I thought they were all crimped. I've never seen a soldered version.

[C Norton]

Wow you've done well to find a Frsky receiver!

[Depron Daz]

Posted by Kevin Wilson on 20/03/2014 23:20:02:

On my current build I considered gluing all the servo connectors as they stand into one block making a single multi pole connector. I am sure it would work.

Instead decided to use a 9 pin D connector. But then I am very comfortable with soldering.

Interesting seeing a balance plug being used. I thought they were all crimped. I've never seen a soldered version.

I chop the servo plugs off and solder to the wires on the balance lead. I buy the leads which have male and female ends and about 4" wire. I guess they are balance lead extensions? I cut them in half so now I have a paired set, and just solder as I described above. For a pair of wings I make sure one side has a male socket and the other wing has a female socket, and vice versa inside the fuz, so that when I connect the wings on, I know I will never connect the wrong wing to the wrong plug.

[Former Member]

[This posting has been removed]

[stu knowles]

Thats a clever piece of kit. I have a biggish twin nearing completion, one wing has four servos, the other three so it has the ability to cut down on the rats nest wiring that is building up. I guess that my only reservation is that it then makes the single remaining plug super critical, which might not be such a good idea in my situation

stu k

[Danny Fenton]

The more I see of this Taranis Tx the more impressed I am. That is a really neat feature Chris!

Yes sure you can wire up multi pin connectors but this is way simpler, and simples is good.

Cheers

Danny

[Chris Bott - Moderator]

Posted by Andrew Ray on 21/03/2014 08:41:16:

Chris, is that the SBUS to PWM decoder?

Enjoyed your review in the latest mag and looking forward to part 2.

Thanks Andrew, yes it is indeed the SBUS to PWM decoder

In typical FrSky fashion, there seems to be one or two unannounced versions.

Mine looks like this

T9 are advertising one that looks like this

and I've also seen one with pins, but the pins are all standing straight up from the PCB.

[Chris Bott - Moderator]

Posted by stu knowles on 21/03/2014 09:05:09:

Thats a clever piece of kit. I have a biggish twin nearing completion, one wing has four servos, the other three so it has the ability to cut down on the rats nest wiring that is building up. I guess that my only reservation is that it then makes the single remaining plug super critical, which might not be such a good idea in my situation

stu k

I agree Stu, we are then using one connection. But then, on the size of model I'm considering them for, I have a single servo plug carrying all the power to the Rx and all servos, not just the wing ones.

Ashloks have the advantage of a mechanical latch.

I like the idea of balance plugs too, although I don't know how they fare with vibration?

[Bob Cotsford]

Chris, I have just this very minute opened a delivery from Rich at T9 and the decoder is the same as your first picture.  It looks as though they just replaced the flyleads with headers for servo plugs.

Pity I only ordered one to play with as I could do with a few more for multi servo wing models.

I do wonder how they will cope with 3 or 4 high power servos drawing current through them. For the average 40-60 size model they should be fine though.

 

Edited By Bob Cotsford on 21/03/2014 12:28:01