Full RX Wiring Diagrams

[Andy-B]

Originally Posted by rdlohr

Thats what I started with and I had problems. There are a number of threads related to it but as I remember the bottom line was you may have problems with sats. I have used many sats on VBARs without issue, but using them with the Bavarian Demon was problematic for me.

Rick

well this is a bit of a bummer. Were you getting the brownouts happening?

Sorry for the poor grammer above. My phone thinks it's pretty smart.

Originally Posted by rhodesengr

take a look at the FAQ for newcomers in the stickies. It discusses the Sat issues and what they are sensitive to. Sats can be made to work. I have a 550 setup with Sats-only and never had a problem but I have a big external ESC, a 5S NiMh buffer battery and running DSMX at 11ms frame rate. Demon Joe himself has posted here that full RX is the preferred setup. Plus, that lets you use preset failsafe which allows you to have SL come on if you lose signal. Sats-only does not allow that.

Yeah, I did read the faq. Thinking about it now though, I sort of quickly read it and to me it was "can I use just sats? ... oh totally you can" hahah

That's why I went ahead and picked up a used 3x for a good deal.
Going and reading it again now, reads a bit more like "dont do it"
I just assumed all these modern fbl units are fully capable to work with sats.

The 3x is for my first build on a x3 (hahah never noticed that little word play before) I also got a good deal for a used koby 55 esc and will be using the align 460mx motor, mks ds93 / 95i servos. On 6s
Any way to say if that can work?

[rhodesengr]

Originally Posted by Andy-B

Any way to say if that can work?

so the truth is that you can find Sat issues with every FBL controller. It is not an issue only for BD. I have been through the VBAR thread and you can find Sat issue there. I am surmising this is because none of them have actually licensed the technology from Spektrum and they have all reverse engineered it. There are plenty of guys (including me) that have it working. The keys to success are solid voltage supply at 6V or more and binding DSMX at 11ms (not 22ms). Some of the older Spectrum TX's like the DX7 did not give 11ms option.

There are various ways to get a solid voltage supply. If you have 6V servos, then you should use an external BEC set for 6V. You can also run most 6V servos with LiFe (nominal 6.5). Even better if you have HV servos so you can run higher system voltage. The problem with small models is that guys tend to use ESC's built in BEC's and a lot of them are under powered. The Talon series has bigger BEC's. Not sure about yours.

At the end of the day, you can make Sats work but no one here is going to say it is as good or better than full RX. The best you'll hear is "mine work and I've never had a problem"

[Andy-B]

Maybe I should just use a full rx then.
Does a full rx solve the voltage issues. ? Edit: or is a full rx solving the communication issue between tx and fbl, those things that needed reverse engineering?
Would I still need an external bec?

Thanks for the help by the way

[rhodesengr]

Originally Posted by Andy-B

Would I still need an external bec?

I think a lot of folks run 450's and such with an ESC BEC combo. You should ask that question or search in the section for your model. You will probably find that some do and some don't. I am most familiar with Castle and they say on their website bot to use the Edge series ESC BEC on helicopters bigger than 500. The Talon series have big BEC's but no data logging.

Using an a full RX makes your system less prone to brown-outs due to voltage sags and the DSM mode and frame rate become nonissues. Use a Sat with an RX designed for Sats and you will probably never have any signal issues.

[rdlohr]

I really like sats and really wanted to use them but I caved and went with a full size RX. Have not had a glitch since.

I could have tried to beef up my BEC but there was at least one guy that was having problems even with a high end BEC. At the time it was unknown what his problem was. Maybe he was using 22 mS.

Rick

[Andy-B]

Thanks for the detailed information guys.

So I picked up an ar8000.

On the diagram with using an esc with bec -in my case a koby55- the first one on top.
The throttle lead wire is split ??? My esc only has one lead coming out of it with three little wires, red brown orange or black brown orange I think, on the connector. What's going on there?
Will I need to splice in and add another connector?

[rhodesengr]

Originally Posted by Andy-B

The throttle lead wire is split ??? My esc only has one lead coming out of it with three little wires, red brown orange or black brown orange I think, on the connector. What's going on there?
Will I need to splice in and add another connector?

The idea in diagram 1 is to use a Y cable. So the ESC plugs into the Y. One leg of the Y goes to the AR8000 throttle port with no cutting. You want all three wires there. The other leg of the Y goes to the 3SX servo4 but you want to snip the orange wire on that leg. Orange is the signal wire and you only want power (red and black or brown). You could plug the ESC cable direct to the RX and tap into the red and black wires for the 3SX but you should probably just use a pre-made Y. This does add an extra connector in the power path but unless you are very comfortable with soldering and working with small wires you should use a Y and not do the tapping yourself.

Another option is to just plug the ESC cable directly into the RX throttle port and forget about the tap or Y going the the 3SX. The 3SX and servos will still get power through the cable loom. It will work fine although the 3SX instructions say to route power directly to the 3SX

[Andy-B]

Makes perfect sense now.
So just one of these would work

http://www.helidirect.com/electronic...flat-wire.html

[rhodesengr]

Originally Posted by Andy-B

Makes perfect sense now.
So just one of these would work

http://www.helidirect.com/electronic...flat-wire.html

well sort of. Want you really want is a Y with one female and two males. I just looked around and was surprised to see that they are all one male to two female. frustrating.

You can use ones like the one you posted but you also need a male to make to make the second female a male. So that adds yet another connector. Seems all the ones on the market are intended to drive two servos from one RX output which is very common for planes with ailerons. Nobody making these cables is thinking about splitting an ESC output.

With that in mind, I suggest you simply plug your ESC into the RX Throttle port and be done with it. Like I said before, the 3SX and the servos will get power through the cable loom.

[Andy-B]

Yes it was hard to tell, but I thought it looked like it was backwards from what I need. Also frustrated that nothing seemed to be on the market for this.
There is a great electronics shop in town, I'll see if they have the right connectors. I'll bring the esc in there and see if we can make a nice Y .... otherwise I'll just hook it up to the rx and call it a day.
K that problem is solved.

I'm feeling a touch of anxiety and intimidation about the whole build -hence all the endless questions- I'm thinking that, I just need to dive in and start learning hands on as I go.

Thanks again for the help rhodesengr

[rhodesengr]

Originally Posted by Andy-B

Thanks again for the help rhodesengr

anytime. I think we all get that anxiety on a new build and when learning a new FBL system. You will see, it is really pretty simple. Just go through the setup two or three times following the wizard.

[jrvetter]

Hi, I am new the this forum. I am considering purchasing a Trex 450 w/
a BD3sx and the new DX7. I read that it is best to use one or two SPM9645's due to space limitations. However I am not clear at all on what I need for power. Can you provide a diagram for this configuration? Also what
tail and head Gyros ar best for this? Any advice would be greatly appreciated.
Thanks

[rhodesengr]

Originally Posted by jrvetter

Hi, I am new the this forum. I am considering purchasing a Trex 450 w/
a BD3sx and the new DX7. I read that it is best to use one or two SPM9645's due to space limitations. However I am not clear at all on what I need for power. Can you provide a diagram for this configuration? Also what
tail and head Gyros ar best for this? Any advice would be greatly appreciated.
Thanks

Hi and welcome. Not sure where you read its is "best" to use Sats as it is well known that using is a full RX is really "best" in terms of reliability but does use up more space.

First, if you haven't already, please read the FAQ for newcomers sticky as it will answer a lot of your questions.

Power connection, if you decide to still use Sats, is simple. You just connect an external BEC or battery through the Servo4 port. Or, if you are using an ESC with a built in BEC, power will be delivered on the Throttle port. So just plug your ESC cable into the Throttle port and that's it. If you do plan to use an external BEC or battery (a good idea especially with Sats-only) Just make sure you don't connect two different power sources like an internal BEC and an External BEC.

BTW, this is covered in the BD3SX instructions which you can download from the BD website.

Not sure what you mean about head and tail gyros. The BD3SX is a head and tail gyro by definition. Did you mean head and tail servos?

If you have other questions not related to power connections (like servos) probably best to start a new thread as you will get more responses.

[MaGooRc]

Originally Posted by rdlohr

Enjoy!

Rick

I have another config: one ESC with internal BEC but with 2 cables, one cable with tricolor wires (throttle signal, output, ground), and another wth bicolor wires (output, ground)

Please someone could post cables/wires options in this case

[rhodesengr]

Originally Posted by MaGooRc

I have another config: one ESC with internal BEC but with 2 cables, one cable with tricolor wires (throttle signal, output, ground), and another wth bicolor wires (output, ground)

Please someone could post cables/wires options in this case

Its just the same as the first diagram but you don't have to cut the signal wire because its not there in the first place. Just plug the 2 wire cable into servo4.

[MaGooRc]

Originally Posted by rhodesengr

Its just the same as the first diagram but you don't have to cut the signal wire because its not there in the first place. Just plug the 2 wire cable into servo4.

No problem to split power between BD unit and receiver? So it would be better to plug Bicolor cable in to some free channel of receiver?

Obs: ESC manual describe which 2 red (output) and 2 black wires are connected IN PARALLEL to the output end of the BEC. Then, second cable only should be connected if necessary highter amparage.

[rhodesengr]

Originally Posted by MaGooRc

No problem to split power between BD unit and receiver? So it would be better to plug Bicolor cable in to some free channel of receiver?

Obs: ESC manual describe which 2 red (output) and 2 black wires are connected IN PARALLEL to the output end of the BEC. Then, second cable only should be connected if necessary highter amparage.

BD3SX prefers that main power connection go to the 3SX. This is because most of the amp draw is from the servos. If you only connected power to the 3SX, the RX would still get power through the cable loom. However, the ESC needs the Throttle signal from the RX so you have to plug the three wire plug into the RX. That leaves the 2 wire plug to connect to the 3SX. There is no problem doing this and I advise you do.

FYI, my 700's power from a battery. I split the battery to two servo plugs. One goes to the RX and the other to servo4 on the 3SX. So basically the same as I am telling you to do.

There is no downside to using both cables from your ESC. You get two connections and power direct to the 3sx. If either one ever wiggles loose, your system will still run off the other. So you have redundancy.

[DEMONjoe]

Refering to the manual:
"As high servo currents can occur, a voltage supply should be routed directly to the device, also in case of a master-slave supply. So the receiver will be supplied via the system, not vice versa.
When using the supplied cable loom and an ESC’s master BEC (running the throttle) is connected to the receiver anyway, the power supply to the servos via cable loom is sufficient. In this case, any slave supply should also be routed to the receiver."

Meaning: it is best not to split up any BEC/power supply between Rx and unit. Get all power to one of each.

[rhodesengr]

Originally Posted by DEMONjoe

Meaning: it is best not to split up any BEC/power supply between Rx and unit. Get all power to one of each.

but this causes confusion because I think you are saying not to supply power to the RX if you supply to the 3SX. That means cutting the red wire on the 3-wire plug from the ESC. Isn't it better to not cut the red wire to the RX? Its one BEC with one voltage so having one go to the 3SX and one to the RX shouldn't and hasn't cause (me) any problems.

[DEMONjoe]

Don't cut anything. Get both plugs to one unit only, either the Rx or the system.