New Corona; what electronics? (Full Version)

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theLane -> New Corona; what electronics? (5/18/2006 5:04:14 AM)

Hi there,

Well, this is not a very busy forum. Is the Corona a dying breed?

Anyway, I am buying a new Corona, but I wanted to check with you first. My local hobby shop has a Corona with an aluminum crutch; seems to be the latest. There is no motor ESC or Gyro so, I ask you, what is best for the heli? I want a brushless setup and I would like to use Lipo's later on without having to upgrade anything.

This is what I have now:

JR XF421EX and servos (I don't think the micro servos are suitable)

What should I buy for electronis?
What battery should I buy?


-= Thanks =-



beaner -> RE: New Corona; what electronics? (5/18/2006 6:40:59 AM)

Hi Edoc,

The Lite Machines Corona is a durable, stable flying model. In fact I liked it so much that I purchased another and now have two. I have been flying the Corona for over 2 years and hundreds of flights and I still enjoy it. Many different combinations of electronics will work in the Corona, I am using an Astro 20 brushless (voyager), I tried the Astro 20 (Corona) but the Voyager has a little more power. I use an 8 cell NIMH 3300Mah pack with Deans connectors. The 8 cell pack provides better performance for the Corona and I get about 8 minutes of flight time. I use a Castle Creations Phoenix-45 speed control, although the Phoenix-35 will work. I’m just more comfortable with a speed control that can dissipate more heat and take a higher surge current. I use HS-85MG servos for elevator and aileron and an Electron 6 receiver. I have found that the ball bearing/metal gear servos operate smoother and repeat better and these are desirable characteristics for cyclic control. I fly a JR 410t gyro in one Corona and a JR 500t in the other. The 500t has remote gain. They hold rock solid and I have had no problems with either one. To improve flying characteristics, a cnc swash plate, 5 mm titanium main rotor shaft, and belt driven tail rotor really makes a difference. Those I purchased from Ballistic Technology. Perhaps others will post their setups offering you more choices. Anyway, I hopes this helps.

Beaner



Cambo -> RE: New Corona; what electronics? (5/19/2006 12:04:23 AM)

High, saw your post earlier.
For a faster moving Corona Forum go rcgroups.com
Got to the helectric heli forum. It is not completely dedicated to the Corona, but there are many Corona pilots there.

I decided to get the multiplex 4d. I have since found out that the Corona likes a Kv between 3000-3500. This engine has a kv of 3200. It is the cheapest so far that i have found and that is what light machines recomends. Don't get the 3D though. Its Kv is way to high, 4000 or so. It will get really hot. As for the speed control i went the the cc 35, wich i think alows you to upgrade to Lipos later. I got both of these of www.towerhobbies.com
It sells for 155 for both but there is a discount of 20 dollars for an order of 120 or more. I always have liked tower for there monthly discounts . For batteries i went with cheapbatterypacks.com
It had great service, they custom biuld packs for you. I went with the elite 3600 cells. Came out to 42 dollars a pack.

I have been told that this setup should give me in the 10 minute range.

Good Luck



Cambo -> RE: New Corona; what electronics? (5/19/2006 12:07:32 AM)

It is www.cheapbatterypacks.com and if you were wondering went with an 8 cell pack



eflier -> RE: New Corona; what electronics? (5/22/2006 3:59:54 PM)

Also...you can use the mega 16/15/3 .. I use this on mine with a Castle 35 amp speed control and it works fine on 3S lithiums. Servos are just the hitec hs 81. Futaba 240 gyro..........have had this since last fall....works just fine....



theLane -> RE: New Corona; what electronics? (5/22/2006 4:07:38 PM)

How much runtime are you getting eflier?

BTW, thanks for the suggestions people!



gadget01 -> RE: New Corona; what electronics? (5/22/2006 5:23:21 PM)

Get the gy-401 and the 9650 for the tail- rock solid combo that you can move to a bigger heli later on.



Freakazoid -> RE: New Corona; what electronics? (5/31/2006 9:21:52 AM)

My bird is running an astro 020 aswell, but im not too happy about it, as it seems to boil up a bit. Its hitting 66'c/150'F when ambient temps are 16'c/60'F. Flight times arnt impressive at all eighter.

@Beaner: How hot did your corona version run and under what conditions?



beaner -> RE: New Corona; what electronics? (6/1/2006 8:07:05 AM)

Hey Freakazoid,
I have flown my Corona in some pretty hot weather (in the 90’sF). If I fly it hard the motor does run quite hot. I never got a temp reading on the motor but I was concerned too, so what I did was mount a small 12 volt computer fan in front of the Astro 20 motor. I connected the fan leads to the speed control battery connector. So anytime the battery is connected the fan is running. The current that the fan consumes is so small that it has little if any effect on the flight times. And the motor stays much cooler. I also did some research, it seems that the Astro 20 uses Samarium Cobalt magnets which can withstand higher temperatures and have a high resistance to demagnetization. However, on the downside these magnets are a bit more brittle. The specification sheet for the Astro 20 indicates a 300 watts maximum. My Corona uses about 153 watts to hover. I’m not too concerned about the heat anymore as I have over 150 flights on this motor and it still has plenty of power.

Hope this helps.
Beaner



Freakazoid -> RE: New Corona; what electronics? (6/1/2006 8:18:07 AM)

How heavy is your bird? Mines 49oz.
Can you give specs about what grips, what pinion, what battery, etz?

Also, ive tried the fan thing, didnt do anything for me.

[img]http://airtoimedia.nl/web/upload/Freakazoid/Images/Small/Corona/Corona15.jpg[/img]

[img]http://airtoimedia.nl/web/upload/Freakazoid/Images/Small/Corona/Corona16.jpg[/img]



gadget01 -> RE: New Corona; what electronics? (6/1/2006 10:11:42 AM)

Interesting modification to that muffin fan. If the motor is still too hot with that setup, it's because it is not running at it's happy-place rpms. The battery voltage/gear-ratio is wrong for the desired headspeed. That is assuming there is nothing wrong with the esc or motor.



Freakazoid -> RE: New Corona; what electronics? (6/1/2006 10:21:35 AM)

Heheh "Happy-place RPM". [:)]
So what are you suggesting? Try a smaller pinion?

It would be great if I could fly with 3s lipo and perhaps a jetranger canopy on it, but I guess this motor just isnt cut out for that job?



beaner -> RE: New Corona; what electronics? (6/2/2006 9:40:36 AM)

Hey Freakazoid,

My blade pitch is 5 degrees, 8 cell Nimh 3300Mah, stock main gear and pinion, belt driven tail. My Corona weighs 48.6 oz. ready to fly (canopy and battery). Looks like we have twins[:D]

Which Astro 020 do you have? The Astro 020 “Corona” is a 4 turn 3300kv motor while the Astro 020 Voyager is a 3 turn 4400 Kv motor. Parasitic drag also consumes power, is your drive train smooth and free (no binding, bad bearings, tight gear mesh)?

The bottom line is that it takes about 150 watts (about .21 HP) to hold my 48.6 oz. Corona in a hover. If I change my gear ratio in order to gain a mechanical advantage the cost will be climb rate. I could then use a higher Kv motor to gain back some of the climb rate. However, at the end of the day it comes down to efficiency. That is, how much of the battery’s power goes into lifting the helicopter and how much is dissipated in the form of heat.

Beaner



Freakazoid -> RE: New Corona; what electronics? (6/2/2006 10:01:15 AM)

Hi Beaner,

Sure looks like twins indeed. :D Except mine seems to be a bit feverish. [&:]
Mines chugging away on a Astro 020 Corona, 3dot grips, 9T pinion (stock?), and 7 or 8 cells NiCD 2400.
Im not particularly happy with the preformance. The heat is putting me off, flight times are a bit iffy, and I dare not get any bigger batteries then these 8cell 2400's because the darn thing already weighs a ton and I dont want to squeeze the motor any harder then its already dealing with.

Im thinking of buying an HT 350/12-12W 10 P motor for it. Apparently it hovers a corona at only 13A on 3s lipo. Its got a built in cooling fan and everything, and ive seen coronas fly with full scale jet ranger bodies using this motor. It can haul 5000mAh of lipo for up to 25 to 30 minutes comfortably.

What do you guys think of it?



beaner -> RE: New Corona; what electronics? (6/3/2006 6:46:37 AM)

Freakazoid,

Is your main rotor over speeding using 3 dot grips, have you tried 4 dot grips? Your motor may be operating out of it’s optimum efficiency range. I am flying one 4 dot and one 6 dot for an average of 5 degrees of pitch. It seems to be about right (for me anyway).

That motor your thinking of getting looks SWEET! The site was not in English so I couldn't understand too much. I like the open frame which allows for air circulation. If you do try it, let us know how it performs.

Beaner



Freakazoid -> RE: New Corona; what electronics? (6/3/2006 9:31:06 AM)

Astroflight said jack up the RPM, the heat will go away. I started off with 4-6 just like you, and now im at 3-3. It got temps down 1'c though, but thats not quite the solution. It already hovers this heavy bird at half throttle now, so id be more tempted to try 2 dots.

One thing is certain, this motor wont be able to deal with 10 minutes of flying with a bell222 body with real retracts. Apparently that LRK motor can do it without a sweat.

Heres some videos of that motor inside a scale corona:
BK 117 scale body (German Rescue helicopter)
-
Jet Ranger scale body
-
Showing howmuch grunt its got left with the body on



ally katz -> RE: New Corona; what electronics? (6/3/2006 5:47:41 PM)

Hi, I am using Nimh 3300 on a Corona with a Mega 16/15/3 and Castle Creations 35 Speed Control. Is there any big advantage to upgrading to Li-po's or am I better to stick to the Nimh's. I am only getting the hang of this Corona and can just about hover in one place. I bought this helicopter built and with some upgrades (carbon fiber fly-bar and crutch, aluminum swash-plate) battery came with it and has about 8 -10 minute's of hover time. If the Li-Po's are better what exactly do I look for. Thanks for any help. Ally Katz

P.S. Sometimes the motor wont start when I first apply power, or it will turn for about 2 seconds and cut off. The motor gets hot from doing this. I usually spin the rotor and stand back before giving it some juice, which tends to work sometimes. Other times it works with no problem. Could the motor pinion be too close to the big gear? or do I have something more serious going on!!



Freakazoid -> RE: New Corona; what electronics? (6/3/2006 6:29:09 PM)

Hi Ally,

If you plan on going on lipo, you can expect 3 things: Higher RPM, Lighter AUW, and LONGER flight time.
But be sure to let the motor get its RPM. That means a smaller pinion, and even go a dot smaller on the blade grips. It should roughly hover at the same point of your throttle stick as it did with the old setup. Higher head RPM means more stability, Lighter AUW means it gets more nimble on the controls, Longer flight time means.. well, spending more time doing what you love. [:)]

As for the "cogging" motor, im not sure what to think of that. Nothing is binding? When you give the head a shove, does it spin to a stop nice and smooth, or do you hear and/or see a slight "chugging"? The only time ive seen a motor do this, is when it had a break in one of the coils so it kept kinda miss firing. One thing you could do is get a meter and measure resistance. It should be the same on all leads. If not, something is screwed up inside and id reccomend sending it to mega motors for a check, as these things are to expencive to just chuck out. But be sure its nothing else messing things up first though. [:)]



beaner -> RE: New Corona; what electronics? (6/4/2006 6:50:01 AM)

Hey Freakazoid,

Now you did it, you had to post video.[:D][:D][:D] Now that I seen it, I have to have one and I didn’t want to spend any more $ on my Corona. Now it looks like there might be a new fuse as well as a new motor for the Corona.[:D]

quote:

One thing is certain, this motor wont be able to deal with 10 minutes of flying with a bell222 body with real retracts.


Agreed.............Do you have a link to the fuse?

Thanks,
Beaner



Freakazoid -> RE: New Corona; what electronics? (6/4/2006 10:04:27 AM)

Any ol' Bell 222 will do, Ill just have to make the retracts myself I guess.[:)]

Heres how the tiny's do it:
[img]http://www.rcgroups.com/articles/ezonemag/2004/mar/ims/19.jpg[/img]

But I dont think a servo can deal with 50oz worth of helicopter bouncing around on it. [&:]
Got any ideas for nice locking mechanisms to take the load off the servo?



theLane -> RE: New Corona; what electronics? (6/4/2006 5:33:11 PM)

quote:

ORIGINAL: Freakazoid

Im thinking of buying an HT 350/12-12W 10 P motor for it. Apparently it hovers a corona at only 13A on 3s lipo. Its got a built in cooling fan and everything, and ive seen coronas fly with full scale jet ranger bodies using this motor. It can haul 5000mAh of lipo for up to 25 to 30 minutes comfortably.

What do you guys think of it?


Wow! If I knew exactly how that setup worked, I would be putting my order in right now. Do you know anyone that uses this motor/setup? If so, can you get more details about their setup other than just the motor?

Thanks



Freakazoid -> RE: New Corona; what electronics? (6/4/2006 7:31:04 PM)

I mailed the owner of the site and videos, to ask what exactly he is using, and how succesfull it is. We already know it can haul 5000mAh of lipo, AND a jetranger body, AND it can do so for ATLEAST 25 minutes. Perty impressive and worth investigating. [:)]

Ofcourse ill let you all know when I find out more.



theLane -> RE: New Corona; what electronics? (6/6/2006 1:46:59 PM)

Good plan. I want the same setup.

I wonder if that motor would mount using the stock setup. I'm still building my Corona.



Freakazoid -> RE: New Corona; what electronics? (6/6/2006 2:11:05 PM)

Assuming its not simply to fat to mount where it should, I wonder if it will allow the big pinion it needs because of the low KV. Even though the motormount can be scooted towards the front quite a bit. If not, youll have to drill the slide mount holes out a bit to allow even more spacing.

But then again, theres always beltdrive. [:)]



gadget01 -> RE: New Corona; what electronics? (6/10/2006 12:52:20 PM)

Belt drive is definitely the way to go- just wish there was an autorotation hub available.



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