Nogyro

My Feedback: (10)

Some people aren't interested or capable in cutting the ends off their servos and hard wiring everything in. There's always several ways to accomplish the same thing. No one way is the correct way, that's what makes this hobby so enjoyable.



I also see no reason for this thread to turn into a pi$$ing match. There is lots of good info being exchanged here, and I for one would like to keep it that way.

houdinimkii

http://www.allaboutcircuits.com/vol_1/index.html

Here is some light reading for anyone interested!

Rcpilot

My Feedback: (78)

This is how I powered my 30% Extra w/75cc engine.

I made reference to this setup on page 3 of this thread. It works.

The batteries are high discharge and can deliver more amps than I'll ever draw with this plane. The battery leads are 14ga with Deans connectors.

The switches are Smart-Fly SuperSwitch HD with 18ga leads in and out. They have Deans connectors in and out.

The regs are old style Smart-Fly with 18ga leads and Deans connectors in. They will pass 5 amps continuous and 9amps on a surge. Output from each reg is 3 heavy duty 20ga leads with standard servo connectors.

Input to the left RX is 2 of those 30ga leads. The 3rd lead powers the Matchbox for my elevators.

Input to the right RX is 3 leads from the regulator.

I should be able to get 5 amps continuous into each RX. I should be able to get 9 amps into the right RX in a surge situation. The left RX is limited to about 6 amps because it's only got 2 servo connectors into it. The Matchbox should get 3 amps if it needs it.

The regulators are my weak link. Some people would say I don't need them with 6V MH batteries. These batteries will read about 7.3V for the first 2 flights. It makes my JR digital servos jitter and I don't like it. So I'm using regulators. I have the regulators set to 6.3V output.

I've debated on getting a better regulator. I'd like to have something that will pass 10amps continuous. If I had a better regulator, I'd solder one more 20ga servo lead to the output on the regs and put power to the unused port on each RX. Right now I have 6 ports filled on each RX with 1 empty port. The Smart-Fly regs work and I haven't really flown the plane hard yet. So far this power system has been flawless.

flatspinjim

My Feedback: (3)

Hey Rcpilot. How about if you ran 2 A123 batteries? Then you wouldn't need the regs. Looks like a nice setup

Nogyro

My Feedback: (10)

Rcpilot,

I've seen your post on your setup before and it looks good. You've got the load really spread out without the use of a PE. When the NiMH batts wear out, give the A123's a try, I bet you'll like them.

I thought about giving your system a try, but wanted to try out a PE. Never used one before. And buy the time I purchased another AR7000 receiver, convert my switches the Smart Fly HD, the price wouldn't of been that much different. I also don't run Matchboxes, so I loose the option of plugging in extra power leads into the system there.

Rcpilot

My Feedback: (78)

I might switch to A123 some day. For now, it works. There are other ways to do it. I will admit my system may be a bit overkill for a 90" plane under 20lbs. Thats the point of this thread, isn't it? We all do it differently. Most of us are aware of the power demands on our large models. We just need to decide what's best for our personal tastes. Some guys want a PE. Some guys don't. Some guys want dual batteries. Some guys don't.

mrbigg

My Feedback: (21)

All good, but some people seem to think that a power expander is needed and that's the only safe way to fly a giant scale plane. No peeing match here. Enjoy, I'm gone.[sm=lol.gif]

thevirginian

RCpilot,
I have pretty much the same setup in my 35% Sukhoi. I am not concerned that my servos are not getting what they need. The reason I am using two receivers is twofold: Added insurance by having two intead of one and spreading the load out evenly. With two 3600 LiPo's (25C) I am not worried that I run into a snag while flying.

Jake Ruddy

My Feedback: (40)

I used A123s for the last year and to be honest, I am jumping off the train this year.

It's great to have 50c (which you will never use) but I am sick of charging every day at the field. It never fails I am charging when no one is in the sky and I could be 3D'in nice and low, breakng the pattern while everyone else is flying their mouth.

On top of that with li-ion I can now run a 4300 2s2p pack for an extra 1.2oz and use 7.4v with no regs. More voltage, nearly twice the size, and a 1.2 oz hit? Kind of a no brainer to me, infact you can run 8600 for 2.4 oz and fly all week without charging.

I am sure some will say the li-ion can't handle as many amp load as the A123.. this is true, but I guarantee if you had 2 identical planes, servos, etc and the only difference was a PE / A123s compared to Li-ion packs there isn't a pilot in this big debate that could feel the difference... it's all in your head. In fact with the li-ions you will have another volt so you will have more torque on the one plane. Replace the li-ion with lipos and charge them out of your plane and you have the same senario.


Edit: This is not to say I dont think a PE is a nice product. I have a SF PE Sport plus which I use. Why? I like how everything is nice and clean, I like the built in ignition kill, and the failover for 2 batteries.

However, now that Hitec is publically saying 7995s and 7950s can use handle 7.4 volts and JR is releasing 8711HVs the scene has kind of changed.

Hammbone

My Feedback: (309)

You make some good points here. I don't have to recharge my A123's at the field, because I rarely fly more than 4 to 6 flights in a day, and my A123's handle that without recharging easily, but the extra voltage and extra torque are attractive to me, especially now that Hitec has given the thumbs up on 7.4 v.

Do you know the amp rating on the batteries your talking about switching to? Is it 8 amps?

Jim

yarom

My Feedback: (82)

I don't really understand the need to recharge at the field, unless you fly 10 flights or more.

The consumption on any 35% or 33% I fly, is around 100mah to 125mah, per battery, per flight. Very slightly more if you have two servos per aileron. I record this value and mark it on the plane when I recharge.

Since I use two A123 2300mah packs, that would give me at least a dozen flights with a very large safety margin (40%).

For 50cc planes I use two 1100mah A123s. It consumes less (like 80mah per flight) and I can safely do 7 flights without even thinking about it.

The A123s can be charged on the PE or externally in just 10 minutes, if needed.

I always carry a couple of charged 1300mah LiPos in the radio box, just in case I want to fly more (never happened). They just connect to the PE exactly in the same way the A123s are connected...

All the above assumes you have properly adjusted servos and no binding...

Jake Ruddy

My Feedback: (40)

Your flying style is clearly different then mine judging by your mah usage - Thats why you can't understand it



My timer is set at 20 mins on my 35%er - I fly minimum 4 times during a week night.. during a weekend day in the summer I probably fly 8+ most days.

I like to fly my sequence 3 or 4 times and then throw in some 3D or an entire flight of 3D. I do lots of snaps, HAKE, and rollers.


I know I used more than 250 on a 15 min flight in my 88" EF Extra with 5 servos, no binding and surfaces not even completely maxed out. I would guess closer to 350-375mah but I can't rememeber the exact # to be sure.


Sure they can be charged in 10 mins if you have 2 x 10AMP chargers and a power supply taht will handle that. I have a Cell Pro.. 4amp charge x 2 batteries. Sure I can buy 2 of everything by why bother? All the sudden you are driving a second vehical for all the support equip.




Ham: I am not sure.. undecided yet.

drewbags

Certainly my usage is less than that; on my EF 110 YAK I am using 16mah per A123 per minute, so a 15 min flight is 225mah, so could get 9 flights before charging. This is 3/4 IMAC sequences and then full on 3D. My CARF 2.6m uses less as I only have one servo per wing. Personally the A123s are the most flexible batteries I have used.

Eagleburger

i think that HV is the future, mine anyway.

yarom

My Feedback: (82)

This is consumption per battery on a EF Yak 88, with 5 Hitec 5955s and 1 Hitec 5645.

Flight are 12min average which would make it 200mah per 12 min flight. Typically IMAC and some 3D at the end when we get silly and the CG moves aft a bit...

Ignition is similar, or 100mah per flight.

Tired Old Man

My Feedback: (1)

Unless JR changes the gear composition in their HD digitals it won't matter a twit how much voltage they can handle. Sorry, I really like JR products but they need to fess up and fix an old problem.

Back to servo voltages; why do we need servos capable of full time 7.5 and higher voltages when we have excellent power sources that can deliver all the amperage we need for a strong and fast servo at less than 7.5 continuous? If we take the time to set things up right to begin with all that extra voltage, amperage, servo torque, aong with a couple of gfanged servos, probably won't be needed. In effect we are becoming our own worst enemies by insisting we have more and more power at more and more cost because we are too stupid to learn how to do things right.

We've largely fallen into the accessory gimmick game. Might as well all change genders and go shopping for shoes, bracelets, belts, and ear rings.....

Hammbone

My Feedback: (309)

Why higher voltage servos with higher torque?
So we can use less servos and save weight. We could use one servo on a 40% elevator instead of 2. We could use 2 servos on a 40% rudder instead of 3.

Besides, if you don't want more power, I have to wonder about your gender.


Jim

Rcpilot

My Feedback: (78)

[:'(]

There's already a couple of those (cross dressers or transgendered..whatever ya call it) at our club. Ya can't even stand around in the pits and tell disgusting jokes anymore without somebody whispering that you're not being PC.

flatspinjim

My Feedback: (3)

T.O.M. I'll second that! Keep it simple!

flatspinjim

My Feedback: (3)

Rc pilot, come join LAMA we're all men out this way!

Rcpilot

My Feedback: (78)

Me and a buddy have been threatening to come up and fly with you guys. We need to set up a time on the weekend and pay you fellas a visit to check out the club.

Hit me up with a PM or email and send contact info so we can make arrangements. We've got AMA and all that stuff. Does your club allow guests to fly once or twice a year?

Hammbone

My Feedback: (309)

Can you explain how using servos with less voltage, less torque is simpler than using servos with higher voltage, higher torque?
I'm at a loss on that one.

Jim

flatspinjim

My Feedback: (3)

Hamm, believe me I'm not against newer better technology, but I also don't believe you have to run out and buy every new gimmick on the market. When Hitec came out with the 5955 it was the end all servo, everyone had to have them. Now they come out with the 7955 and the market is flooded with used 5955's because everyone wants the 7955's. The companys selling the newest, latest, greatest have everyone convinced that they can't fly without them.
One of the best pilots in my club flys a 35% QQ yak with 5955's all the way around, 9 total, all on 1 2600 nimah. He's flown this plane for 4 years and competes and wins at lot's of IMACs. He's very precise with his setup though

Hammbone

My Feedback: (309)

If you don't want the latest, greatest, then don't buy it, but you didn't answer my question.

Jim

flatspinjim

My Feedback: (3)

Would you use a PE with a trainer running 4 standard analogs?