talon58

My Feedback: (125)

What kind of switches are you guys using in your large planes? Also what battery packs? Do you guys run 3 packs (receiver, servo's and engine) along with 3 switches?

Just purchased 28%, with a DA-50. Kind of an step up from my Funtana 90, OK maybe a large leap up!!!

Thanks in advance.

Tired Old Man

My Feedback: (1)

I've been using the DSC switches from Cermark for a few years now. I have never had a failure in any of the 20 or so switches I have purchased.

I also get my extensions from them. I like being able to get the different connector colors at no extra charge for color coding during the installation.

As far as batteries are concerned, you don't need to install a bunch of redundant systems in a 28% plane. It only adds weight and complexity. A good high capacity nicad, Duralites, or Powerflights will be fine. Just make sure you have good, solid connections and dependable current flow to your radio system. Check the battery status before and after each flight and you will be more certain than most about the condition of your batteries.

Your biggest enemy will be mechanical vibration from the engine, so make sure that nothing can wiggle loose, and isn't flopping around inside the plane.

Stick Jammer

If you can afford an additional 5 or 6 ounces in all up weight, dual Rx packs/switches is a definite advantage in redundancy, well worth the $40. As mentioned, dual Rx packs in a 28% is not typically the norm. I am definitely not a fan of having the servos on one pack and the Rx on another as you have no battery redundancy in that situation which totally defeats the purpose. Most definitely a separate pack/switch for ignition as you mentioned.

Tired Old Man

My Feedback: (1)

Talon,

It's going to be a lot easier than you think. Just don't over think the installations. A separate ignition battery, around 1000 or so mAh will do. It must have it's own, dedicated switch. Try to keep items associated with the ignition separated by as much as possible from the rest of the flight radio components. I like a minimum of a 2000 mAh battery pack for the flight battery if I am using digital servos. Check it often.

If you feel that you must have battery redundancy, look at some of the isolators out there. ED products and i4C are two that come to mind that are reasonable in price. They both effectively prevent RF feedback to the receiver, and provide a separate power bus for the receiver. Separate switching set ups are also described in their instructions. Some like them, some don't. I'm one of the former.

Dual receivers have been known to cause more problems than they have solved. You can read more about that in several forums, including the Wild Hare Support Forum. There is a lot of information there for the first time giant flyer.

Learn to worship blue and green Locktite at any and all threaded connectors. It will become your best friend. Discard any thoughts you may still have about using 2/56 hardware. 4/40 just became your minimum standard.

Disregard any and all horsepower ratings. There are no set standards between the manufacturers. Most horsepower ratings are derived at rpm levels you can't use, anyway. What you care most about is pounds of thrust and rpm. The truth of those numbers will be found by yourself experimenting with different props, and the ACTUAL performance of the engine/prop combination on the plane.

It's all basically the same as you have been doing, just larger.

Have fun.

Silent-AV8R

Here's what I run in any plane over 25%.

Dual RX batteries into 2 switches (one per pack) plugged directly into the RX. A separate ignition pack with its own switch as well. And I ALWAYS use an optical kill switch on the igniton circuit as well.

No isolators, pack switchers, etc. None of that is needed.

For a 28% plane you can easily run 2 1000 mAh NiMH 5 cell packs, get 2,000 mAh capacity, and simple redundancy with no added complication.

Here's a for instance:

2 x 1000 5-cell NiMH packs at 3.6 each = 7.2 ounces
2 x 1400 4-cell NiCad packs at 4.8 each = 9.6 ounces.

A single 4 cell 2100 NiMH pack is 4.1 ounces. 2 packs is 8.2 oz.

SO little weight to get perfect redundancy. Go here to read about dual packs:

http://www.rcbatteryclinic.com/

I ran dual 1000 packs in a 27% (80") MW CAP 232 for 3 years with never a problem.

I run a 33% 540T with 8 digitals (8411's) with dual 2700 5-cell NiMH packs. I average 25 ma per minute drain. I can get 2.5 hours of flying in with a 30% reserve. But I usually put them on charge after about 1.5 hours to feel warm and fuzzy.

Like the one post said, don't over think this or over complicate it. All you need are 2 packs adding up to 2,000 mAh capacity total with 2 switches into the RX. Nothing else is needed. Keep it simple and you will have a long time of happy flying.

I also use the Cermark DSC switches. Never a failure in several years and 2 dozen switches.

Bill

JohnVH

My Feedback: (38)

I agree with some of the above.

33% and smaller I run
Single RX
Dual RX batteries into two switches into two seperate ports on RX
Battery for engine, typically same size as RX pack.

40%
dual RX
one battery per RX
One battery same size for engine

These setups work great for me so far.

stomper

My Feedback: (20)

Aman!

deputydog

I agree with Silversurfer. My 33% has single rx, 4000mah Duralite Plus rx batt and 6 servos, All digitals(except throttle!). I fly all weekend without a charge. KEY WORD.... "KISS" keep it simple stupid

JohnVH

My Feedback: (38)

I have some Li-ions coming, man, Im looking forward to not having to charge every 3 flights!

RCJones

You guys don't talk about battery size. I've seen some unusual sizes lately like 4/5 A. Is AA the norm for everyone? I have a ton of sub c nicads that I hate to not use but the nimh's are making my sub c's look pretty bad.

Are the 4000mah AA size also or bigger?

Greg McNair

My Feedback: (3)

My current project, a 1/3 scale helicopter, will not have a switch. That's one more failure point that I will eliminate. On previous builds, I have used dual batteries/dual switches and a Jomar Ultimate Battery Backer, and I am considering using the Jomar with two packs, but no switches. Gotta check with Jomar to see if this will work.

Tired Old Man

My Feedback: (1)

If you need the weight somewhere, run the sub-c batteries. They DO have a lot of capacity. That's what it's all about, capacity. More milliamps are better than less, regardless of battery type.

RCJones

AA batteries have as much capacity now as many sub-c cells so I guess weight would become the deciding factor

chasrb

Okay, lots of good info here, let me run my setup buy you guys...

33% lainer Laser 200 (used) first gasser for me. I am no 3D guy just basic IMAC stuff.

Brison 4.2

1 RX

4 HS645MG's for the rudder and ele halves

2 HS5645MG's for the Ailerons

1 HS 422 for throttle

EDR optic kill switch

EDR pow'r bus pro

1 1100 maH NiCd ignition batt 4.8v

1 1700 maH NiCd RX batt 4.8v

1 3800 maH NiCd servo batt 4.8v

3 HD MPI switches

shakes268

I'm pretty much in the same situation as the original poster. I want to go the Li-Ion route and have been looking at a lot of different things.

So how come Airwild and other sites usually still have something like the power expander from Smart-Fly in the basic packages?
I was thinking 2 Li-Ions (2400 mAh), a Smart-Fly SuperReg switch and that would pretty much do it right? 1400 NiMH on the ignition with a DA-50. I don't mind spending the money for a power expander if it helps and considering the fact that the Li-Ions are 2 cell packs that saves quite a bit on weight to offset the use of the other stuff correct?

JoeAirPort

My Feedback: (41)

Rx: Smart fly Super switch and a 5 cell 1950 NMh from NoBs (Sanyo HR-4/5FAUP 1950 Nimh 5 cell). The switch has dual connectors that go to the receiver.

Ignition: Cermark/JR HD switch and 1100 NiMh from NoBs (1100 series GP 2/3 A Rx pack 5 cell).

This combo will fly a 28% two days on a single charge (or 12 flights).

In the future if I decide to go with a two battery rx system on 30% and below I'd use three of the above 1100 mah NiMh and three Cermark/JR switches.

Panzlflyer

My Feedback: (15)

The last 2 33% ers I saw crash were both battery failure ( single pack setup ).
If you take a Duralite apart you will note that the wire is small and a lot depends on the diode which I have been told is the weak link as the solder melts real easy causing intermittent glitches or crash.
The diode is there to prevent charging into the output wire.
All in all the construction of the 2 packs I took apart was 2 weak to depend on even in a 28% mainly on the wiring side.

CHM

My Feedback: (28)

Digital servos really suck current. I have two Expert 1500 NiMH 5-cell packs with two JR HD switches into two ports on the receiver. I can only get three 20 minute flights on my H9 Sukhoi (3D style) and then I'm in the yellow zone on my ACE meter. I have a 1400 mA NiCD 4-cell on the ignition. I'm running 2 8411s, 4 8231s, 1 Hitec 5735, and two standards for choke and throttle. I'm upgrading to a pair of larger batteries in the spring. I'm going to try NoBS packs. I've heard good stuff about them. I have a 27% ZDZ-40 powered Cap 232 with all analog servos. I'm running a 5-cell 1100 mA NiCD in there and it's plenty for 7 analog servos for 3 or 4 flights. I couldn't afford reduntancy when I built it, but I will be upgrading later.

To answer your question... I believe switches fail more than batteries, and receivers fail less than both. (I'm assuming proper battery care when I say that) At the very least I would buy the best HD switch you can find, especially if you are only running one switch and battery. The best way to go (to protect your investment and maybe someone's health) would be dual Rx packs and switches as the other guys said.

Buy a good load tester that puts a realistic load on the batteries and check each one before each flight. Then, after I start my Sukhoi, I switch one battery off at a time to make sure each is working under vibration. Make sure you have a helper holding the plane.

I have never read about a failure with the JR heavy duty switch jack. My friend had a switch failure on his GP Pitts. I believe it was an MPI switch. I have heard good things about the Cermark switches too. It's simply not a place to try and save a few bucks. Buy the best and don't fly it unless everything is right.

Once you go big you won't go back...unless it's a foamie!


Chuck

shakes268

This thread has been certainly helpful for me. I'm just paranoid about battery/power solutions - mostly about safety than anything else. Someone I fly with has told a story of his switch failing and his 30% flying out of the field and headed toward the baseball/softball fields. We fly at a state park (with designated model airplane field) that usually has a lot of people in different areas of the park during summer months. That is why even though it's a 28% plane I'm building I do want some redundancy.

So what do you guys think of the smart-fly SuperReg with a failsafe switch? If the switch fails, power to the regulator is ON and cannot be shut off until you disconnect the battery packs. Also, they are dual-battery regulators so you can run 2 Li-Ion packs off of one regulator. (yea, single point of failure is now the regulator - but I'd assume good ones to be about as reliable as you can expect)

Josey Wales

My Feedback: (61)

I think its a confidence issue as well..I just feel better knowing I have an extra battery/switch on my 28% and 30%..I know its not needed but for me it is..I like to worry about stuff!!

BTW I have all Fromeco stuff 2 2400 for rx with the regulators..

Rcpilot

My Feedback: (78)

I just stepped up to a 90" Extra.

I called the guys at www.radicalrc.com and talked to Chris. He has high discharge metal hydride battery cells. I think they will take 15amp continuous discharge--maybe it was 20amps?? Anyway--they are big enough. I ordered 5-cell packs with 18ga. leads coming off them.

On the end of the lead--I'm solderong a Deans connector.

Then I bought the Super Switch from www.smart-fly.com
http://www.smart-fly.com/Products/Switch/switch.htm

It's got a Deans connector going in. It's got 2 standard connectors with 22ga. wires going out.

I don't have a RX with enough ports (8ch) to run all my servos and still plug in a battery pack--and I want 2 batteries. So--I'm going to use dual RXs. Even if I had a 10ch RX--I wouldn't have enough ports. I need to plug each servo into it's own port--NO Y-HARNESS'[:'(]

Each RX will have a single battery plugged into the Super Switch and then dual leads plugged into the RX.

I'll be putting about 6 or 7 amps into each RX.

I'll have 4 digital flight control servos on each RX. And then a standard choke servo on 1 RX and a standard digital throttle on the other RX.

I'm using a 1650mah 6V metal hydride battery on my ignition and a Hobbico HD switch.

ICE_MAN

I'm building a 34% here's my set-up, maybe it will help:

1 FROMECO 480 MaH for RX

1 FROMECO 2400 MaH on Ignition

2 Fromeco Super Regulated reliaswitches.

sillyness

My Feedback: (25)

I sw someone said they were going ot run 2 LiIons into one reg... you really want two regs if you are going to run 2 batts... regs fail too. Don't give yourself a weak point.

I use the NoBS 1950 NiMh through a SuperRocker switch for ignition. I have dual Fromeco 2400s through 2 Fromeco SuperReliaRegs into the RXs. This is in a 35%. Works good, last a long time. I still don't buy all this power expander, power bus nonsense... more stuff to give up the ghost.

Bob_S

I too am "going big" for the first time with an Aero Works Yak. (I can't wait!!) I was looking at a single 4800mah li-ion pack and 1 voltage regulator for the rx. Wouldn't 2 2400 packs and 2 regs (both connected to the RX via Y cables) provide some redundancy with very little weight gain? The only cons to this I see are slight more weight, cost and complexity. The pros are redundancy.

Thoughts?

Josey Wales

My Feedback: (61)

Yes..2 2400 packs will weigh the same as a single 4800..the only extra weight is for the reg


I had a single Fromeco 4800 and switched it to 2 2400's..I like to worry about things