Still Confused about No of Rx and use of powerbox set-up

[jamiem]

Can someone share with me how I might find the powerbox? I've looked at the smart-fly power expander but I like the idea of the built in regs on the powerbox.

[jack01]

http://www.aircraftinternational.com/powerbox_index.htm

[Bunky F. Knuckle]

I have seen PBX's cause problems. You can have issues with anything. I use 1 Rx and the i4c Isolator. It saves the Rx from all the current that the servos get. I have used it for the past 4 years, no probs!!

Ultimately, it is your choice. I have seen guys use 1 Rx in 40% birds, and have seen 2 Rx's in 40%'s as well. I've seen the PBX's in there as well, on 1 Rx. If I were to do a 40%, I would use 1 Rx adn use the Isolator, in place of a PBX. Why?? I feel more comfortable with the Isolator than I do with a PBX. Why, again?? Personal preference, that is all. That and I like the KISS method!!

It all comes down to what you want to use.

Bunk~

[Hoss]

Jack, so if I understand you correctly your reciever is getting more than 6 volts? I was playing around with my powerflight regs and adjusted them to deliver 6 volts on my longest lead under a 1 amp load, I had to adjust my regs to about 6.75 under no load to achieve this. So my questions is would this create any issues going to a Futaba rx?

[Hoss]

From Jack01

The way my Extra is setup is just two batteries, two older Powerflite adjustable regulators, two switches, and one reciever.

- The Powerflite regulators are adjustable, so I have them set to deliver 6.0 volts under a 1 amp load on my longest extension.


Jack, so if I understand you correctly your reciever is getting more than 6 volts? I was playing around with my powerflight regs and adjusted them to deliver 6 volts on my longest lead under a 1 amp load, I had to adjust my regs to about 6.75 under no load to achieve this. So my questions is would this create any issues going to a Futaba rx?

[dunny]

Have you looked into Emcotec DPSI RV unit for a power distribution unit? IMO for the time and money spent on a big airplane, the extra $$ for these units is minimal. Some people think these units aren't necessary, but if your wiring and connections are done properly, you can draw more current than you think. My 34% extra at idle on the ground (5 5945's, 4 5955's) draws 4+ amps with no bottlenecks from wiring or connections.

Dunny

[Kiwi]

Dunny,

4 amps at idle is some super serious current draw mate. I mean seriously. If thats correct you will kill a set of 2400 MAH batteries in an hour without even getting off the ground.

I just recently setup a system with four ganged rudder servos, Dual aileron servos and singles on elevators. Digital 220 oz no name brand.

With everything at neutral I have 300 milliamps load including the receiver draw included. If I cant get my idle load below 500 milliamps on any of my planes they dont fly. Full stop.

I dont mean to be any sort of know it all or anything but mate, that is seriously way too much.

How do you measure your current draw, are you sure its 4 amps and 400 MaH. I would really like to help you out if possible to see if thats correct. If it is I'm also sure we can get it way down.

Kiwi

[Hoss]

I have run the emcotec DPSI before and liked it, I will probably go with the smart fly system when it is available. I was just very curious about Jack's post thought I would see what it would take to get 6v on my longest lead and what the volts to the rx would be.

[dunny]

	Quote: Originally Posted by Kiwi
	Dunny, 4 amps at idle is some super serious current draw mate. I mean seriously. If thats correct you will kill a set of 2400 MAH batteries in an hour without even getting off the ground. I just recently setup a system with four ganged rudder servos, Dual aileron servos and singles on elevators. Digital 220 oz no name brand. With everything at neutral I have 300 milliamps load including the receiver draw included. If I cant get my idle load below 500 milliamps on any of my planes they dont fly. Full stop. I dont mean to be any sort of know it all or anything but mate, that is seriously way too much. How do you measure your current draw, are you sure its 4 amps and 400 MaH. I would really like to help you out if possible to see if thats correct. If it is I'm also sure we can get it way down. Kiwi

Emcotec BIC- measures current draw- min and max and tells you what your minimum and maximum voltage is during the flight. I can only speak of my own experiences, but the more research I did, the more it made sense- these Hitec 5955's are a whole nother animal compared to say a 5945- the Hitec web site says 5945 will max 1.5a vs 4.2a for 5955!!! I could probably write a whole page explaining how I got into finding this stuff out, but if you have your wires, switches and connections done so there are no 'bottle necks'- more current can be drawn than one could imagine. I'm no expert on this stuff, but due to a battery failure on my Extra, it made me want to understand all this battery/ wiring/ power stuff a little deeper.

Dunny

Oh yeah, this is with servo/ linkage geometry done correctly(no binding)!!

[exeter_acres]

	Quote: Originally Posted by Hoss
	So my questions is would this create any issues going to a Futaba rx?

several rx's (I can't find it right now) were tested and they all far exceeded 20 amps

[NCFR!!]

OK - so here is a question. On my 40%, I have always used the duel receiver with battery to each and split the plane. I had a battery failure once and dinked the plane because half of the servos were just flopping freely. I can definatley see the advantage of using one receiver. Now - I am switching from 6 8411's, 2 Fut 5050s, and 1 9202 to 8 Hitec 5955TGs and 1 Fut 9202. Can I just use the one receiver or do I **NEED** a powerbox / power expander? For batteries, I am using 2 4800 Fromecos with Fromeco regulators (plus a 2400 on ignition).

[adrian]

the powerbox/expander is the way to go - to many advantages to mention - its all about redundency today on a 40%. lots of info about it just do a search.