update on a redundant onboard system

[Beaublus]

Hello everybody!

I am now assembling a Pilot rc extra 330LX 2.6m. However I have been away from giant aerobatic planes for 10 years now and I need your help on the electronics required on board.
When I was flying , we didnot have HV servos and these kind of fancy stuff. I was using multiple servos with a power system. To be exact, I was using powerbox and Smartfly expanders with 8 or 10 servos and nimh or liion batteries.
Things have gone a little crazy with onboard systems and I am struggling to set up my mind on a reliable ( and not too expansive) way to go.
I have done some research and went through a lot of new devices and new brands.

Here is where I am now :
I have bought a Futaba T16 transmitter to be able to use telemetry and maybe sbus servos. And two r7008sb hv receivers.
As for servos : I was initially going to use 6 Savox 1270, a Savox 2290 on rudder and one fast servo on throttle. But I may go for futaba s9177sv ( or even BLS 172) as they are not that expansive on rcjapan.net.

What I like to do with my setup is this :
I would like to use a Booma smart switch redundancy with two lipos batteries (2S 5000mah) that will feed my two 7008sb Hv receivers. I will put half servos on one receiver and the other half on the second receiver. I will also use a Smartfly ignition cut with an extra battery.

I like this setup because it is simple, fully redundant ( 2 batteries, 2 receivers) and it uses all the programming power of my transmiter.
However I am a bit concern about the peak current drawn by the HV servos and power losses because of the lack of a regulating system as an expander.


Do you think what I am planning to use is relevant for a giant aerobatic aircraft with the new HV electronics?
Do you recommend to use an expander, or the HV receivers will handle peak current drawn directly from HV servos?

Thanks for the help and updates you can offer!!! I am open to any advice as I have a 10 years gap to fill!



PS :
Here are some links to the hardware I would like to use :

http://www.boomarc.com/en/smart-swit...h-technology-2
https://www.smart-fly.com/ignition-c...eceiver-setups
https://www.rcjapan.net/index.php?ma...sbjd8cdoht75j2
or
https://www.rcjapan.net/index.php?ma...sbjd8cdoht75j2
https://www.rcjapan.net/index.php?ma...sbjd8cdoht75j2

[itizme]

https://www.rcjapan.net/index.php?ma...sbjd8cdoht75j2


http://www.thunderboltrc.com/index.p...oducts_id=1035


http://www.thunderboltrc.com/index.p...oducts_id=2360

You can add GPS, Powebox telemetry, to the mercury

2 - Lipo 7.4 for power, Ultra IBEC takes power from your distribution so no extra battery needed for ignition

This is how we roll over here

[Beaublus]

Thanks itizme.
I have seen the nice servos package rcjapan is selling. I dont know how much the customs will take but I think I am going to try. It seems to be a pretty good deal.
Thanks also for the Ibec thing. It is a good way to get rid of the extra ignition battery. Thanks!!!
Does this Ibec do a good job to prevent ignition noices?

As far as the PB mercury, that is the big question. Do I really need one? My transmiter will handle more programming and mixing than needed for the plane. I dont see the point in using the matching system on the PB when my transmiter can do the same.
My real concern is peal current and maintaining the servos performance during the flights.

Beaublus

[flyloose]

Thanks itizme.
I have seen the nice servos package rcjapan is selling. I dont know how much the customs will take but I think I am going to try. It seems to be a pretty good deal.
Thanks also for the Ibec thing. It is a good way to get rid of the extra ignition battery. Thanks!!!
Does this Ibec do a good job to prevent ignition noices?

As far as the PB mercury, that is the big question. Do I really need one? My transmiter will handle more programming and mixing than needed for the plane. I dont see the point in using the matching system on the PB when my transmiter can do the same.
My real concern is peal current and maintaining the servos performance during the flights.

Beaublus

If power distribution and over voltage protection is what you want (I think it’s a requirement with 35% and larger, jets, etc) then there are a few options to go with nowadays. Powerbox make an assortment of SRS systems, some with built in gyro (Mercury) and others without. Booma RC has a sister company called AR, here’s their Futaba unit:

https://pacificrcjets.com/products/a...a-s-bus-s-bus2

Or this one is multi compatible with the different radio systems, and built in gyro to 26 outputs ...

https://pacificrcjets.com/products/a...nd-gyro-system

I think you actually need a power distribution system that you can have 2 receivers plug into....

Just my opinion of course..

Eric

[itizme]

Thanks itizme.
I have seen the nice servos package rcjapan is selling. I dont know how much the customs will take but I think I am going to try. It seems to be a pretty good deal.
Thanks also for the Ibec thing. It is a good way to get rid of the extra ignition battery. Thanks!!!
Does this Ibec do a good job to prevent ignition noices?

As far as the PB mercury, that is the big question. Do I really need one? My transmiter will handle more programming and mixing than needed for the plane. I dont see the point in using the matching system on the PB when my transmiter can do the same.
My real concern is peal current and maintaining the servos performance during the flights.

Beaublus

Like Eric said, the PB systems ( I have two of the SRS Champion systems ) will give you that two receiver redundancy as I am sure many others will as well.
The Ultra IBEC is amazing. also has a simple jumper for output voltage selection and that's what makes it nice. I have several of them and a couple of the Powerbox SparkSwitches but unfortunately the PB Units are either 5.9 or 7.4 output, you buy one or the other.
If you plan to run 500 ounce servos then you likely want to use power distribution to avoid the brown outs.

[flyloose]

And many of these units will give you voltage regulation as well, which broadens your options regarding servo selection....7.4v or 6v

[itizme]

And many of these units will give you voltage regulation as well, which broadens your options regarding servo selection....7.4v or 6v

or combinations of both 6v and 7.4

Hi Eric

[Beaublus]

Hello friends.

A big thanks for all the tips you gave me. I really needed an update.
As I understand, an expander will be required. I thought I could get rid of it with 3 or 4 servos on each receiver but these receivers can't garanty the same current during the flight so....
The Futaba Booma RRS looks good to me. Nice fetaures for a reasonnable price. The Powerbox Mercury is nice but is overkill for my needs.

Three more questions guys :
Is someone selling an expander that provides regulated current for the servos from two batteries without all the servos matching and extra options?
What are the goals of the gyro thing that you can find in some expanders ( the mercury for instance)? I don't get what they do.
Futaba, with their Sbus system, allows us to simply the wirring onboard. On paper, that seems to be the future, but I don't see that many people using it. Why that?

Again, thanks everyone!
Beaublus

[Beaublus]

And I am definitley buying the Ultra Ibec!! No more ignition battery!! WOOOwww!!!

[JBajkor]

You need to check this out: https://www.frsky-rc.com/product/redundancy-bus/

Connect 2 batteries, 2 receivers with one SBUS wire each. This is an expander using redundant batteries and Rx. It will monitor current to each servo and shut down any servo that seems to be stalled. Amount of time and current for servo shutdown is in the specs. This is a fraction of the cost of PowerBox products! I don't know why more people are not using these????