Anybody try 2 batteries in parallel

[mikejbb]

Anybody try 2 batteries in parallel for almost double the flight time? I have the connectors and will probably try it tomorrow. So that would be almost 8g of battery.

If that works then maybe even the 11g batteries at 400mah could be used, they are almost free. That is 6 batteries - 10c - 400mah for $13.99 shipped on ebay. They're for that W... machine that is he who must not be named. But thats a lot of extra weight and might be a problem messing with the motors.

adendum: It failed to fly see below

[SQRT(-2)]

yes, but my soldering was not the best, most of the draw was from one battery so I really did not gain anything. Remember, with increased weight is increased power to stay aloft and faster drain on batteries. Decreasing returns.

[HazPat]

the high voltage will fry your mcx. stick to one cell. 3.7 volt anything else is super pointless. you will gain absolutely nothing from it but a smokey bird.

[SQRT(-2)]

In parallel the voltage is not increased, only the amperage potental. in searies the voltage in increased.

[mikejbb]

Yes sqrt, the v's are the same and the power is doubled. I soldered it together today and tested the polarity and v's and all was good. So I hooked her up and the led came on and she flew about 6 inches off the floor. So 3.6g's extra is just too much for my current mcx. I think my previous motors were stronger, but it doesn't matter, it failed to fly. Oh well, I unsoldered the connectors and I've flown with a single battery to be sure everything is still fine, so no harm no foul.

[SQRT(-2)]

well nothing ventured, nothing gained. At least you can afford to expiriment with these things. I would be terifyed to experiment with those bigger birds.

[mikejbb]

Speaking of terrified, my godson has a blade 400 he's been flying for awhile now. He sims all the time and I've seen him do a bunch of 3d stuff with the 400. He seems to be a good pilot. He also has an mcx. Yesterday he was just doing a roll and the 400 didn't respond to the controller and it crashed and parts went everywhere. Blades of course shattered, inner shaft bent, cf tail boom snaped, and a bunch of smaller stuff broken. OMG, I would like a bigger more responsive bird, but not at that cost. I was watching him control it and it really did not respond to his commands.

[HazPat]

doh! series..... parallel....... i get confused. still more power and more weight only means more stress on the motors.

[tweav]

Did you do the more pitch mod to your's before you tried the 2 batteries ? I heat the blades to reshape them zip tied to a pipe .I make mark on the pipe so I can put the next blade the same place . you need two marks one for the upper and one for the lowers. I use a heat gun on them till they get soft enough the conform to the pipe . then just wait till it cools down or dip it in water then repeat it on the other 3 blades.




you have to be careful not to overheat them or they warp bad. I've ruined a few ,the more zip ties the better I may try wrapping them with a wire.

[dealwagon]

How much more lift does this add? Is is a LOT more powerful?

[mikejbb]

I like it! How about using a small piece of sheet metal that is bent around the pipe part way so you don't need the zip ties and it might make for a smoother curve with less warping. I don't have a heat gun, what else can you use to heat it? Is a hair dryer hot enough? Maybe put into a toaster oven with controlled heat?

Also only people looking for parallel batteris will see this great idea, you might want to start a new topic.

[chippies83]

Originally Posted by mikejbb

I like it! How about using a small piece of sheet metal that is bent around the pipe part way so you don't need the zip ties and it might make for a smoother curve with less warping.

Failing a piece of scrap metal, one could use three or four pencils. Just put them ontop of the blade, and then zip tie the pencils down, pressing the blade on to the pipe. The force would distributed across the entire length of the blade, and would prevent the waviness that might happen with zip-ties.

Good idea!

[tweav]

Originally Posted by dealwagon

How much more lift does this add? Is is a LOT more powerful?

Mine is off the ground at a 1/4 throttle nice 4ft hover around a 1/3 stick.

I'm going to try wrapping the blade with kite string and stick a pencil soldering iron in the pipe . but I at really going to watch the temp on this setup. I'm thinking I need about 300 - 350 degrees F. I wonder if it would work if I just deep fry them ? I'll try that first .

and yes a piece of metal over the blade would work fine . I'm not sure but if you built it in such a way that it presses the blade you may not need to heat it . just clamp it in a vise . it would not hold the shape of the pipe exactly but that's not really what we're after here . we are after more pitch that you can repeat the mod over and over

[HazPat]

so what is the advantage of the higher pitch? does it fly differently? are the flight times longer since less throttle is needed?

[tweav]

I Think it is faster all around and it surely lifts more . as far as flight times I've never timed it . most of the time anymore I get bored with it before the battery goes dead.

I am working on a cp / cx2 half breed . to see if I can make a twin head tail less heli that can fly inverted and still have the stablity of the twin heli. If I can work it out I'll then convert it over to brushless.

[PlastikPilot]

Originally Posted by tweav

Mine is off the ground at a 1/4 throttle nice 4ft hover around a 1/3 stick.

I'm going to try wrapping the blade with kite string and stick a pencil soldering iron in the pipe . but I at really going to watch the temp on this setup. I'm thinking I need about 300 - 350 degrees F. I wonder if it would work if I just deep fry them ? I'll try that first .

and yes a piece of metal over the blade would work fine . I'm not sure but if you built it in such a way that it presses the blade you may not need to heat it . just clamp it in a vise . it would not hold the shape of the pipe exactly but that's not really what we're after here . we are after more pitch that you can repeat the mod over and over

You want a controlled heat, try holding it in steam from boiling water or put the pipe in the hot water and allow it to warm up the blades, also you could put one blade on each side and have a pair done at one time.

[deswong]

Originally Posted by mikejbb

Also only people looking for parallel batteris will see this great idea, you might want to start a new topic.

Now we just have to get the blades at a good enough angle to lift the heli with a single A123 cell -

[mikejbb]

Here's pix of my 3rd try on recurving the blades for more lift. I didn't fly it yet because I'm letting them sit like this overnight. Also my motors are shot and the new ones won't get here until Wed so they way overheat in less than 2minutes now. And neither of my lhs's carry them .

My first attempt used thread to wrap around the blades to curve them a little more. It worked, but the thread was biting into the thin edge of the blades and the curve then became less. My second attempt was to tape on .5" of thin plastic the length of the blade at an angle down a bit. That seemed to work better, but added 2g's to the mcx so if I do that again, I'll do it some way so it's lighter. I did get my 2min's flying just fine with the 2g's extra weight, throttle seemed to be in a similar position, so that was encouraging. I suppose curving the blades or adding extensions will burn out the motors faster, we'll see.

My ultimate goal is to use the 240mah batteries I just got from hobby city to get 15-20mins of extreme flight times. But I'll need a little more lift or maybe just some weight loss.