Zagi 400 conversion to Lipo and Camera setup options?

| > Astro 109 gets my vote.

| Forgot to ask on this.. | | The Astro 109

| states that you shouldnt use an auto battery to charge?

No, it says you shouldn't use an auto battery CHARGER as a power source.

| This seems odd to me, as how would you use it in the field. | | It doesnt include a balancer correct?

No. You could buy an Astroflight Blinkie for about $25 and use it to balance.

This charger is LiPo only. You could get one of the GP Triton models for a similar or smaller price that will do all sorts of batteries. Like this --

If you get bigger models, the AF 109 might be perfect, but for now it's overkill for your needs, and yet underkill too -- you'll probably want to charge NiCd or NiMH cells in the future as well.

And your `Wagan 5.0 Amp AC to DC Converter' looks fine for powering any of these chargers.

| Im now heading towards getting a Twinstar II and upgrading its engines | to BP-21's with an 18amp esc..

You may already be aware of this, but you'll need two ESCs -- one for each motor. Brushless motors can't reliably share an ESC.

has what looks like might be a nice deal. It's a year old, but maybe he still has these?

| In searching I found these batteries and chargers.. any thoughts on | them.. Do I just mod the connectors on the batteries if they wont work | with a given charger/balancer?

Yes.

| Batteries seem a bit pricey:

Hurts, don't it? :)

seems to have some really nice prices. No idea about the quality of these cells, however. I've had PolyQuest batteries before, and they were good, but this seems too cheap. Probably because they're all

8-12C packs, and most people want higher current ratings than that. But for a slow plane, they might be fine.

Yep.. already have that in the budget.. only about $43 for two if I have the right one.

Sure does :)

If i went with the Bp-21, which is only 13amps max.. would it even matter if the battery pack was say 3100, 12 C.. as this would 37.2 amps max draw?

Do the higher C values and higher mah just give you longer run times.. I'm assuming it wont do much for power.. if not hurt the motor?

Still I saw people mentioning using 3s 3100mah.. but they didnt specify the C value.

(I also thought about just going stock and doing the NIMH sub c battery pack (8 cell 9.6v 3600mah) but I cant seem to find many of these and they are $79 at this site

I found 4200mah here $59 but this may take quite a while to charge? So I thought I might as well go Lipo if I'm correct, as the price would be the same if not cheaper, plus I'll gain a Lipo charger (extra money of course).. and eventually I'll enhance my zagi anyway ..)

$99

$79

$48

You are being ripped mate.

Try another supplier.

under 80 dollars for TWO packs,. and whilst they may not be really 15C cells, if you run them around 15-16A, they will fly your plane!

Always go LIPO before going brushless..you save far more weight ditching nickel batteries than ferrite can motors.

geared 400s work very well on 3s LIPO, BUT buy the time you have put a gearbox on, you might as well get a cheap brushless.

BP21s are all right for the money.

(AC to DC)

Oh..its probably a 13.8v or something..its what people used to use to power CB rigs when NOT in the car..loads on ebay ..

Like this

No,. its states you should not use an auto battery CHARGER, to charge.

At least not unless its connected to a battery!!

No. Frankly I think they ar a waste of time. If your pack goes out of balance it's because its already irreperably damaged.

>

Doug McLaren wrote: you'll probably

Not once you buy a LIPO pack..I sold all of my nickels within a month of getting LIPOS..

8C is a pretty good rule for sport flying. You are unlikely to over discharge current or time wise if you stick to that.

I never go much over 8VC and have yet to have a pack go on me from normal use..yes I've flattened a couple up trees...and one on the bench..one is completely dead, the others are about 2/3rd capacity..but my nicely treated packs seem as good as new really.

You also get a slightly higher on load voltage. For a twinstar you can certainly fly it on no more than about 15A at 3s voltages - about 75W per motor.

Unless you want to make a warbird out of it, 2100 pack should be fine..prop the motors back to about 8-9A apiece and it will fly.

My guess is that on cruise, about 20-30 minutes duration.

Go LIPO.

Get a setup that pulls about 200W for a twinstar unless you are an animal.

2408 2409 or 2410 motors will be fine..try and find lowish KV ones that will swing at least 7" props. That suits a twinstar better than 5" or 6" really.

If you find one that is rated for an 8x4 prop and 3s LIPO, at under

10A, get that, and drop down to a 7x5 - then you should have the right mix of pitch speed and thrust, and be able to throttle back enough to get a decent cruise duration.

In article , The Natural Philosopher wrote: | Doug McLaren wrote: | you'll probably | > want to charge NiCd or NiMH cells in the future as well. | | Not once you buy a LIPO pack..I sold all of my nickels within a month of | getting LIPOS..

So your TX pack is LiPo too?

Sweet.. I didnt come across that site.. so that looks good two 2150's for $80 :)

Forgive my ignorance on "gearboxes".. is this an addition that some motors have to run?

I'm guessing brushless doesnt require this (actually.. i still dont know the mechanics of what makes a brushless , brushless, vs brushed etc).. I'm assuming it has something to do with the inner parts

Cheerio

One thing I'm still not 100% on.. is how do I know which will run longer.. on the BP-21 motor (13Amp?) (for instance)...

The 3s1p 2100mah 15C battery pack or a 3s 3600mah 12C pack (43amps) (burst of 16c)

I'm assuming this is all mathematics to get at least a guestimate.. At glance I would guess the 3600mah would last longer, but take longer to charge at the maximum safe value of 1amp?

Addendum:

I did find these chargers that go with the xushobby $79 15c 2150mah 3s battery pack..

$79 for two 15C, 2150mah 3s battery packs

ThunderPower Charger/balancer/AC pack:

$79 ^this one has the ac charger, so I dont need an AC to dc converter for in the house. (actually I dont think this AC to DC adapter idea would work in the house, as it appears most of these field chargers only have alligator leads, not a cig. lighter adapter?)

or

DN charger/balancer: $67.50

(Add $13 for an AC power adapter)

haha. I WISH it was..it keeps going flat. Ive been thinking about adapting it but there needs to be a bit of circuitry to protect it against being left on.

It's a way of trading RPM for torque, so you can use bigger props slower..that suits slower models better.

Outrunner brushless have many poles on a larger diameter stator, so they have a sort of 'built in' fixed ratio gearbox anyway. They don;t need a gearbox but sometimes you still need one for really big props.

The bigger battery will run longer, all other things being equal.

But at a weight penalty.

You never charge at one AMP..you charge at the pack one hour rating..i.e. 3.6A in this case.

Since I get around 30-45 minutes flying off a pack, in general about 3 x

7 minute flights is all I do and it takes around 45 minutes for a full recharge. Cos my packs are never less than 1/3rd full..

That is another reason for a bigger pack..for a given flying time you can recharge effectively quicker, as they will take a higher charge current.

The last 20% of the pack takes a long time to squeeze in, so sometimes flying with a 3/43 full pack is also a time saver.

Still unclear on one thing.. if I have a motor that says it puts out a max of 13 amps.. can I hurt the motor by getting a LiPo with too large a C rating.. IE: 15 or 20C etc...

So say 2100mah * 15C = 31.5 amp.. does this mean the battery will push

31.5 amps towards the motor (or does the ESC of say 18amp in between keep things in check)?

I think your value of going with *C sounds more like a match for the BP-21 than 15C.. 8*2100 = 16.8 amps?

So on a 2100mah battery pack.. I should set the charger/balancer to

2.1 amps (for 1 hour) if it will take that amperage?

*Im not sure what the wording is on this other idea.. but having the ailerons move with the rudder in synch.. autocoordination? Is this possible on any given transmitter or does it depend both on the transmitter and wiring done on the plane. In the case of Twinstar.. it uses the y cable for the ailerons and I'm using a 6xa Futaba (which is fairly programmable)..

*Someone also mentioned they do flaperon type setups with their Twinstars.. I'm assuming this means both ailerons go up or down depending on the switch.. same question regarding this one.

Sorry for all the questions.. I dont yet belong to the local rc club.. so these forums/internet are a great source of info.. you guys have been really helpful in getting going again.. as its been awhile/never done alot of these advanced things :)

Cheers

In article , The Natural Philosopher wrote: | Doug McLaren wrote: | > In article , | > The Natural Philosopher wrote: | > | Doug McLaren wrote: | > | you'll probably | > | > want to charge NiCd or NiMH cells in the future as well. | > | | > | Not once you buy a LIPO pack..I sold all of my nickels within a month of | > | getting LIPOS.. | > | > So your TX pack is LiPo too? | | haha. I WISH it was..it keeps going flat.

And not just your TX pack, but any RX packs you have are probably NiCd or NiMH. (If you just fly park fliers, you may not have any RX packs, but if you fly bigger electrics or gliders or glow planes, you probably do have lots of 4 or 5 cell NiCd or NiMH packs.)

Yes, you can use a switching power source, or LiPos and a regulator for RX packs, but often it's simpler just to use a NiCd or NiMH pack.

And if you fly glow, you've probably got a NiCd powered ignitor, and your starter probably has a Pb or NiCd pack that will need charging.

And R/C chargers/cyclers are often useful with the batteries in things like power tools or cordless phones ...

I just think that even if you fly nothing but LiPo powered planes, it's very useful to be have at least one charger that can do NiCd/NiMH packs (and charing Pb batteries is a nice bonus.)

| Ive been thinking about adapting it but there needs to be a bit of | circuitry to protect it against being left on.

I just replaced mine with 2000 mAh NiMH cells -- it's good for about

10 hours of use, and the self discharge rate isn't a problem as long as charge it at least once every three weeks or so.

If only usenet had the ability to edit posts.. I always think of something 5 minutes later that I fogot:)

I found two escs I was considering:

says if using 4 servos I'd need a 4.8v rx pack or switching BEC.. i'm not sure if that applies in the case of having 2 ESCs and 4 servos, would I really need another battery for the Rx?

I also found this ESC:

states there is no Lipo guard.. I'm not sure what that means or if the base unit is programmable or needs programmed?

I was assuming that a 3s 2100mah 15C (at most 15C) would have been enough juice to power this thing better than stock and for up to 20 minutes as you guys have noted .. 15*2100 is 31.5 amps and the motor is rated at 13 amps.. or do I combine the amps to say 26 amps.. so having a 15C is the lowest I'd want to go? IE: in determining xC rating.. on a twin engine.. do you add the amps of both engines together to get the max/min amps needed?

Alot have said they use two battery packs (one for each engine), but many others just use one pack, but with higher mah's, say 3000 or

4000...

I'm not sure how the ESC's would wire into 1 single battery either.