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Old Jan 21, 2013, 01:48 PM
Specializing in RC since 1972
Temple, GA, USA
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Originally Posted by efx View Post
I just thought of another question...has anyone used two batteries in parallel to power the kk2? I think I can squeeze another 2200 in the middle for more time, but I'm wondering if anyone has done it?
One BAD thing that you can do with this is to plug in one charged battery and one discharged battery in parallel. The discharged battery will get charged way too quickly, perhaps explode or catch fire. You are OK if both packs are within say a tenth of a volt of each other; probably significantly more, but I have not tested more than a tenth. For that you are on your own.
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Old Jan 21, 2013, 02:14 PM
HeliHarry
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United States, OK, Tulsa
Joined Dec 2006
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Originally Posted by theothercliff View Post
String tuning is more diffcult on an X quad. You leave all motors plugged in. The strings need to go half way between the motors to put them on the pitch or roll axis. A dowel may help. I haven't ever done this.
Thanks, you affirmed what I was thinking of doing.
I'm going to attempt it in the next couple of days.
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Old Jan 21, 2013, 02:30 PM
efx
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Thanks Cliff. I think I'll just keep testing the single batteries. I don't need to add any more problems at the moment. I think just a larger amp battery will do the job as well. Unfortunately they just keep getting larger as the amperage goes up too which I'm not crazy about so I may keep it in the smaller batteries until I find what works best. I just want to do a video so just hovering seems to help keep the battery going a bit longer. Crazy flying does bring the battery down pretty fast for me. It could be my higher rated motors too, I'm not sure but then again I just started so we'll see.

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Originally Posted by theothercliff View Post
One BAD thing that you can do with this is to plug in one charged battery and one discharged battery in parallel. The discharged battery will get charged way too quickly, perhaps explode or catch fire. You are OK if both packs are within say a tenth of a volt of each other; probably significantly more, but I have not tested more than a tenth. For that you are on your own.
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Old Jan 21, 2013, 03:24 PM
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I am running Ver 1.4 on a small quad. Self leveling works great except no matter what I do, with hands off I can't get it to keep from drifting forward, even with full trim.
Any help appreciated.
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Old Jan 21, 2013, 03:38 PM
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Originally Posted by theothercliff View Post
Self level is broken in v1.2. You should update the firmware to v1.4 or v1.5 to use self level. I forget whether it works in v1.3 or not.

The way it is supposed to work is:
- turn off self level
- fly and trim it with the transmitter trims
- turn on self leveling
- trim self leveling flight with the self leveling menu ACC trims, not the transmitter trims
I'm already on version 1.5. I use sub-trim to set all zero's in Rx test. No need to trim anything with SL off. As I said ACC trims have no affect at all.

Fred
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Old Jan 21, 2013, 03:42 PM
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Stavern/Larvik - Norway
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Kk as Bgc

http://www.rcgroups.com/forums/showt...804109&page=15
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Old Jan 21, 2013, 06:18 PM
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Australia, QLD, Meadowbrook
Joined Sep 2012
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Ecalc

Found this, its interesting, have a play .Will try to fix link. There Ya go.

http://api.viglink.com/api/click?for...13588413961872
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Old Jan 21, 2013, 06:21 PM
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Italy, Lombardy, Ranica
Joined Nov 2012
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Exacopter settings

Hi, this is my settings for the exacopter shown on my last video at pag. 628 report 9410 hoping this can help for similar application.
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Old Jan 21, 2013, 07:30 PM
Specializing in RC since 1972
Temple, GA, USA
Joined Jun 2009
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Originally Posted by efx View Post
Thanks Cliff. I think I'll just keep testing the single batteries. I don't need to add any more problems at the moment. I think just a larger amp battery will do the job as well. Unfortunately they just keep getting larger as the amperage goes up too which I'm not crazy about so I may keep it in the smaller batteries until I find what works best. I just want to do a video so just hovering seems to help keep the battery going a bit longer. Crazy flying does bring the battery down pretty fast for me. It could be my higher rated motors too, I'm not sure but then again I just started so we'll see.
I didn't mean to scare you into avoiding parallel packs. Really just make sure they are both fully charged (and the same number of cells). You can even use a 1000mah and a 2000mah in parallel with no problem. I would buy batteries that I can use in several aircraft rather than buying expensive large batteries that I can only use in one aircraft.
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Old Jan 21, 2013, 08:30 PM
efx
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Thanks, thats a really good tip. I rather get the smaller ones I can use on my helis than the larger packs. I don't have any plugs to do the parallel batteries. I have to look into this to make sure I don't make any fires either. I found out lipos spark just like any other batteries and it's not pretty either. By accident of course. For safety I only keep a handful of lipos around, but one or two more would even me out. Plus the smaller packs charge a bit faster than the larger packs so I'm with you there. Hadn't even thought about that, but that sounds like some good advice as I'm not doing any far away flying, so that works for me.

Quote:
Originally Posted by theothercliff View Post
I didn't mean to scare you into avoiding parallel packs. Really just make sure they are both fully charged (and the same number of cells). You can even use a 1000mah and a 2000mah in parallel with no problem. I would buy batteries that I can use in several aircraft rather than buying expensive large batteries that I can only use in one aircraft.
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Old Jan 21, 2013, 09:43 PM
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I'm really liking how the KK2 performs on my DIY tricopter. Enough so that I'm starting to test it for FPV. 2.4/5.8 cheap combo bash rig electronics in case something goes wrong. Next I'll replace all metal components with plastic or aluminum to get some performance back.

Tricopter FPV (1 min 16 sec)
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Old Jan 21, 2013, 09:52 PM
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That's pretty smooth video, how do you mount your camera or are you using the keychain type? I know those don't bounce much. I'm getting the shakes a bit on mine so I got some tuning to do.

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I'm really liking how the KK2 performs on my DIY tricopter. Enough so that I'm starting to test it for FPV. 2.4/5.8 cheap combo bash rig electronics in case something goes wrong. Next I'll replace all metal components with plastic or aluminum to get some performance back.

http://www.youtube.com/watch?v=BDNPfr1-jPw
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Old Jan 22, 2013, 01:47 AM
efx
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Well I got another question as I'm not familiar with props much if any until this build. I currently have 8x4 props on the 450 kit. What would be the resutl of say going to 7x4 I guess or 9x4.5 size. I was thinking of going up one size hoping it will help keep the humming down a bit. Well I don't know, I'm just curious as to what both of these sizes will do if I change to them. Obviously the bigger the prop the more power I would probably need since the smaller ones would turn much faster. Well that's my thinking but feel free to correct me if I'm wrong. Thanks.
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Old Jan 22, 2013, 02:51 AM
Specializing in RC since 1972
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Motor, ESC, battery, and prop are a 4 way balancing act.

Assuming first of all an ESC and battery that can handle more power, a bigger prop makes the motor draw more power. The wires in the motor are only rated for a certain amount of power and will burn out if you put too big a prop on it.

For a given motor size (power capacity) say 200 watts, a high KV motor rating translates into a small prop turning a high RPM that consumed 200 watts. A low KV translates into a large prop spinning slowly and also consuming 200 watts. You cannot just put a large prop on a high KV motor and hope that it turns slowly enough to not burn out.

With electrics, you can always safely use a smaller prop. The only down side is less power. You can safely run an electric motor without any prop. It is the bigger props that will make something burn out.

If you have a prop that works well on your motor and does not overheat, start from there. Measure the amp draw at full throttle with that prop and compare it to the motor spec. If you want and need and can have more amps without burning a motor out, you can increase the prop size a little. Even if you can't increase the prop size, you can get more thrust by increasing the diameter and decreasing the pitch at the same time. For more speed and less thrust you decrease diameter and increase pitch. Figure 1 inch of diameter equals about 2 of pitch so you could go from say a 9x6 to a 10x4.

On the internet there are online brushless motor calculators that can help you. Find one that has some defaults for the things you don't understand and experiment. Get an amp meter / watt meter and some reasonable props and experiment. Be careful to never over amp any of the components.

With an amp meter you can increase throttle till you see you are close to max amps. If you get to max amps before max throttle, cut a little diameter off, rebalance, and try again.

One test I use when close is to run it at full power for 10 whole seconds. Let the heat soak out for 10 seconds of power off. If it is too hot to hold firmly, the prop is too big and you shouldn't have done that in the first place. Start with small props and work your way up in small increments this way. Make sure you don't over amp your ESC or battery either and that really requires an amp meter or learned knowledge like the fact that I know that a 6x4 prop on a 3 cell 2000KV will pull about 20 amps.
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Old Jan 22, 2013, 03:05 AM
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Australia, QLD, Meadowbrook
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Give that ecalc link a go now. its not a given but it will give you a fairly accurate guide when choosing props, motor, esc and batteries. Rule of thumb, small diameter, large pitch for speed and large diameter, small pitch for power.
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