• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

QAV250 mini quad motor choice

nilsen

Senior Member
#1
Hi All,

I'm wanting to get onto the mini-quad train and have successfully convinced 2 of my friends to join and get mini-quads as well, I cannot wait to do a FGA style race; That is actually how I convinced them to join, showed them Charpu FPV's Videos as well as FGA and jus70's videos on youtube and they were immediately hooked.

Now we are goint to go for the QAV 250 as it's solid and the dirty/clean section makes for great video however I am considering the motor choices as well as voltage buzzer.
We'll stick to 3s when starting however at some point may want to go to 4s.

1. When using the Naze32 do you need a voltage buzzer separately?
2. The motor choices from Lumenier are 1806-14 2300kv and 2206-11 2350kv.
They are both "rated" for 3s however the one is susbstantially bigger than the other with a similar KV, what would the advantage be of getting the bigger motors since I think the QAV250 is limited to 5inch props, possibly 6 at a push.

Thanks all!
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#2
Then Naze boards do not come with a buzzer, but the hookup is there for one. Ditto for the bluetooth module which makes tuning and setup Night-and-day easier.

Bigger motor, same KV, and higher max current by spec means it can swing a bigger prop for more thrust . . . or run more efficiently under-propped. It'll also make the transition to 4S a little easier, although neither motor is rated for 4S (I doubt no one has pushed it, though). Hard to say if the extra efficiency makes up for the 66% increase in weight -- on a 250 quad that's getting to be kinda heavy.
 

nilsen

Senior Member
#3
Hey Crafty,

Thanks a lot, that makes sense, I entered the values into ecalc and the results were better with the smaller motors, due to the relatively large difference in weight.
I think I'll stay with the smaller motors.

As for the buzzer, does anyone add an external buzzer to these small quads or just fly "by experience" in terms of battery capacity?

Cheers!
 
Last edited:

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#4
Depends greatly on the pilot, but few pilots fly with the "I think it's been in the air long enough". That's a recipie for puffy, ragged out batteries. You *ALWAYS* loose track of time. By the time you see the performance drop significantly, you're already casuing damage.

Some will use timers (stopwatch or radio), some use voltage alarms that plug into the balance ports, some use voltage monitors built into control boards . . . each strategy has it's strengths and weaknesses, but all will need to be calibrated to your power system to know "how long/how low" you can draw on that pack and stay above 3.3v/cell under load and 3.7v/cell resting. Pickign up a 5v buzzer for the naze is a cheap and simple way to go . . .
 

C0d3M0nk3y

Posted a thousand or more times
#5
I think the QAV250 is limited to 5inch props, possibly 6 at a push.
They just announced extensions to allow 6 inch props.

http://www.getfpv.com/qav250-angled-motor-mount-extensions.html

As for the buzzer, does anyone add an external buzzer to these small quads or just fly "by experience" in terms of battery capacity?
I use the built in buzzer connection on the Naze board so it makes a sound when arming etc. Do you know what kind of radio gear you will be using? If you go FrSky, the Naze has battery voltage telemetry built in, so you can just see your voltage at all times.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#7
Definitely add the buzzer.

If you set up failsafe, it will call to you if you ever lose signal and your copter flies away or crashes in a field. It will also warn you if you leave your copter plugged in on your desk and go to bed. It is a very inexpensive way to save yourself a hard lesson.

After my close call, ALL my copters have buzzers.

1806 motors will spin 6" rotors but many are pretty fragile. They tend to fly well until you crash them and then they tend to not fly well anymore. I have more luck with 2204s. I would use 2206s if I plan to go 4S spinning 6" rotors.

I think 4S spinning HQ 6045s will more than make up the weight of a 2206. Any beginner builder/pilots should avoid 4S.

For a mini quad I would run 6030s or 6045s with Cobra 2204s on a 65C 1300mAh lipo if the booms are long enough for 6" props.

Don't fly 5" props if you can help it. I have a Polakium Hex that runs the 1806s and spins 5030s. I have had some success with that setup on 4S but even then, it does not have the power of my 3S Twitchity Mini Hex (G10) running 2204s and 6045s. Because of the limitations of 5" rotors, the Twitchity Mini hex, while a bit larger, performs MUCH better than the Polakium. It corners, stops, accelerates, flips, rolls and spins better just because of the length of the rotors.
 

nilsen

Senior Member
#8
The QAV250 does not have a clean/dirty section.
Ok I re-read the spec and you're right, but the video you see is normally top notch comparted to some others, nevertheless I like the brand and what they have done for the "sport".

From their description:

"Like all QAV airframes, the QAV250 produces vibration and jello free HD recordings. We achieve this vibration free performance without the use of Lumenier's clean/dirty frame separation that is utilized in larger QAV airframes such as the QAV400, QAV500, and QAV540G. This simplifies the small QAV250 airframe, making it lighter, reduces parts count, and failure points."

They just announced extensions to allow 6 inch props.

http://www.getfpv.com/qav250-angled-...xtensions.html
Brilliant, I'll add those to the order for future 6 inch enhancements.

Do you know what kind of radio gear you will be using? If you go FrSky, the Naze has battery voltage telemetry built in, so you can just see your voltage at all times.
I use a Futaba system so it's a no go for me however for the two newbies the sky is the limit so maybe I should go FrSky.


Definitely add the buzzer.

If you set up failsafe, it will call to you if you ever lose signal and your copter flies away or crashes in a field. It will also warn you if you leave your copter plugged in on your desk and go to bed. It is a very inexpensive way to save yourself a hard lesson.
Which buzzer do you tend to add? Just any 5v buzzer? I like the idea, on my large Hex with the APM and telemetry I just just the droidplanner app to monitor all of these things so haven't actually used a buzzer. I think I'll just get some 5v buzzers off ebay, it should work.

For the beginners I'm going to keep them on the 3s system to start and learn but I think they'll progress rather quickly so I want to provision for the 4s system later so I'll probably go for the bigger motors, well actually they just announced the new FX2208-9 2000kv which is rated for 4s use but is also another 15g heavier per motor meaning that for the beginners it would be overkill.

I love and hate this part of multi design, deciding on what you want and need.

Thanks all!
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#9
This buzzer will work:
http://www.hobbyking.com/hobbyking/...KK2_and_KK2_1_Flight_Control_Boards_1pc_.html

2208 motors are gonna be HUGE on a 250 quad. Using 22mm motors with 5" rotors is overkill. You will have tons of power you can't use.

If you are stuck with 5" rotors use 1806s. If you can go 6" rotors, Cobra, and Sunnysky motors are the gold standard. Hobbyking has some I have never used:
http://www.hobbyking.com/hobbyking/...300KV_Multi_Rotor_Motor_CW_Prop_Adapter_.html

At this point, your motor decision hinges on 5" or 6" rotors and that is based on the length of the booms you buy. Make that decision and it becomes VERY simple to move forward. :)
 

joshuabardwell

Senior Member
Mentor
#10
For battery monitoring, there is no substitute for voltage telemetry, such as is done by FrSky. If you can afford to make it happen, do it, and don't look back. The simplest way to get into FrSky with telemetry is to get a Taranis. Around $200 and you're set. You can do it a bit cheaper with the 9xr Pro if you want to go that way. For receiver, the D4R-II set up in CPPM mode is used by many quad pilots. In CPPM mode, you get either six or eight channels, depending on your firmware, so don't let the fact that it's "only" four channel stop you.

If you're not going to do voltage telemetry, a buzzer alarm on the copter is good, but I would also use a timer. The reason being, the buzzers sometimes don't alarm until a lower voltage than I would prefer. And I have also seen some of them that only buzzed off the overall pack voltage, which sometimes results in an individual cell going lower than I would like.

If you're ordering the QAV 250 frame, they just released some ten-degree tilt motor mounts that you might want to look into. This will keep your copter slightly more level in forward flight, meaning you don't have to tilt your camera back as far.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#11
Naze32, the voltage limit is user definable in the GUI. I like to trigger mine at 3.7. :)

Keep the buzzer away from any magnetometers. It is magnetic.

Telemetry is the way to go for normal daily operation. The D4R-II is my receiver of choice also. I also use a timer. I am this retentive. :)

The buzzer is one layer in a series that you can use to keep possession of your copter in the event of a disaster. It is what you listen for the day your receiver loses signal, triggers failsafe and crashes in the tall grass. If you still can't find it, your name on the copter and the general goodness of people is your last hope.


EVERYONE who has lost a copter in this forum will tell you they wish they had set up to anticipate the worst. Use telemetry, put your name on the copter, have a timer alarm on your transmitter tuned to how you fly, set up failsafe on both your Naze32 and your receiver and put the buzzer on the copter.

If you are going to put $200+ in the air take the time to try to keep it.
 

nilsen

Senior Member
#12
Hello Everyone!

Excellent advice on all parts, I placed the order today and decided to kit these things out for 4s however start the guys on 3s.

I went for the angled motor mounts as well so that it can take the 6inch props and therefore went for the 2206 motors, hope it all works out.

Looking forward to getting it all, How very exciting, I think it will be a huge change from the large, stable beasts I'm used to flying with 6 13 inch props on 4S down to 4, 5 or 6 inch props :D

The newbies have ordered frsky telemetry which is excellent, thanks for the tips.
I will use a buzzer and timer and we'll add buzzers onto the naze for all 3 of them. I use the timer at the moment, it's very useful.

Cheers!
 

joshuabardwell

Senior Member
Mentor
#13
Once you see the FrSky system in action, you're going to be tempted. It could be worse--at least the Taranis is a fantastic transmitter, so you don't have to sacrifice anything (except money) to get into the system.