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Old Oct 12, 2011, 10:04 PM
Watt Waster
Tsavah's Avatar
Joined Oct 2010
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Flying Issues

Quote:
Originally Posted by badharley99 View Post
Hi, I have a fun bat that I just built. Had problem with plane porposing. flew just ok at half throtle when I would go full throtle the plane would want to really climb bad. ... didnt a lot of power and you could hear vibration at full throtle, prop is not knicked ... nor is motor shaft bent. Thanks Nick
Porposing is a tendency for the plane to climb, loose power, stall, dive a little to gain airspeed, and enter into a climb to repeat the cycle at a specific throttle setting. If that is what was going on at half throttle or a lower setting you need nose weight, but ... you also said the model would climb bad at WOT, so ... you also need some down thrust angle on the motor. If the motor isn't producing full thrust at WOT and instead tends to wobble, or vibrate with a good propeller, your propeller is not balanced properly. It also means the motor shaft is thin, so it will be very sensitive to a propeller that hasn't been balanced. All motors are sensitive to an unbalanced propeller, but the thinner shafts show it more and quicker as WOT is applied. An electric motor properly mounted with a balanced propeller isn't easy to hear in flight and until that is the case, there is a bit more work to do.
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Old Oct 12, 2011, 11:56 PM
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chris1379's Avatar
United States, OH, Eaton
Joined May 2006
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Quote:
Originally Posted by badharley99 View Post
Hi,

I have a fun bat that I just built. Flew it for the first time tonight with 70% dual rate on ailerons and 70% on elevator.

Had problem with plane porposing. flew just ok at half throtle when I would go full throtle the plane would want to really climb bad. may need to mix in some down elevator as throtle increases.

Have COG at about 2.25 inches back from leading edge

using a 3s 1300 mah battery

this is the motor I am using turnigy 2730-3000
http://www.hobbyking.com/hobbyking/s...idproduct=8620

2 hxt 900 servos

and a mystery 30 esc

http://www.hobbyking.com/hobbyking/s...e_Series_.html

any help would be appreciated to get this thing flying good and level, didnt seen to have a lot of power and you could hear vibration at full throtle, prop is not knicked or anything like that nor is motor shaft bent.

Thanks

Nick
That's not a very good motor for this plane for several reasons. Here are the specs:
Thrust: 320~410g
Prop: 5x3~6x3
ESC: 12A
Max Current: 8.5~11A
Battery Type: 2S Only
Weight 25g

1. You said you are using a 3S lipo when this motor should be used only with 2S
2. It's too light to get proper balance.
3. The max current rating is way lower than your ESC

Take a look at some of the motors others are using. I am using THIS MOTOR with an APC 7x6. As for the porpoising it will probably be cured by moving the CG forward with a heavier motor. When you get it working right this thing is so much fun to fly.
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Old Oct 13, 2011, 09:57 AM
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Joined Jun 2011
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Just built one with elmer's. With a 28mm diameter motor and a 1A 3S at as forward as possible I still need to weight 108g at the nose... Dollar Tree foam is the way to go. Can't wait to maiden mine.
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Old Oct 14, 2011, 01:46 AM
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Bristol,UK
Joined Feb 2007
3,963 Posts
Welcome to RC Groups shuut.
The Funbat is my go to plane at the moment. I did extend the forward fuse to help with balance and mine is built from 6mm depron with a KFm-4 3mm step. For the maiden, I would recommend lowish rates as she is a very responsive model with a rapid roll rate.
Good luck and looking forward to your post maiden flight report.
Andy
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Old Oct 17, 2011, 02:11 AM
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Australia, WA, Madeley
Joined Jul 2011
645 Posts
Just maidened my 6mm Depron Funbat last night, very cool plane. Is my first scratch build and was great to see it actually making its way around the sky.

Great simple and effective design; easy to cut out and fabricate; and just about as bullet proof as a foamie can be. If I can build one anyone can.

Being in Australia and the FB being a smallish plane I was concerned about the magpies having a crack at it (they are vicious this time of year), until I figured out I that the plane was way more maneuverable than a maggie. Spent a good 10 minutes avoiding a crazy bird who eventually just gave up. I assume he got too dizzy trying to follow my loops and rolls.

Its a little underpowered at the moment due to me using a scavenged motor which is too small, but I'll whack a more appropriate one on now that I have it all trimmed up and flying well.

Cheers Jon for making the plans freely available!
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Old Oct 17, 2011, 12:04 PM
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United States, OH, Eaton
Joined May 2006
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Quote:
Originally Posted by Wormboy View Post
Just maidened my 6mm Depron Funbat last night, very cool plane. Is my first scratch build and was great to see it actually making its way around the sky.

Great simple and effective design; easy to cut out and fabricate; and just about as bullet proof as a foamie can be. If I can build one anyone can.

Being in Australia and the FB being a smallish plane I was concerned about the magpies having a crack at it (they are vicious this time of year), until I figured out I that the plane was way more maneuverable than a maggie. Spent a good 10 minutes avoiding a crazy bird who eventually just gave up. I assume he got too dizzy trying to follow my loops and rolls.

Its a little underpowered at the moment due to me using a scavenged motor which is too small, but I'll whack a more appropriate one on now that I have it all trimmed up and flying well.

Cheers Jon for making the plans freely available!
Glad to see another Funbat make it to the skies. I've heard many times about the magpies and it always cracks me up. So, what kind of power system did you use? Do you have some pictures? I always love to see how people implement a design.

Chris
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Old Oct 17, 2011, 03:09 PM
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United States, KY, Louisville
Joined Feb 2011
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Has anyone tried this design in EPP?

I do love fan fold but I prefer EPP for combat.
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Old Oct 17, 2011, 08:13 PM
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Australia, WA, Madeley
Joined Jul 2011
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Quote:
Originally Posted by chris1379 View Post
Glad to see another Funbat make it to the skies. I've heard many times about the magpies and it always cracks me up. So, what kind of power system did you use? Do you have some pictures? I always love to see how people implement a design.

Chris
Couple of pics

Funbat is watching you..
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Eyes were for the benefit of the magpies but they seem not to care in this instance. you probably can't see it too well but there is a hole in the fuse just behind the motor mount where he stuck his beak straight through the Depron.

and a picture of the underside and guts..
Turnigy park450
8x4.2 SF prop
25A ESC
1300mah 3cell LiPo


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Like I said, underpowered but nice to get it flying and to get all of the trims right. I tried a 9x6 E prop but the motor heated up way too much. Better off just upgrading the motor and prop to something better matched and more appropriate.

She will loop and roll but won't go vertical or VTO. Often has a bit of tail wag as well which others have noted at low speed.

I managed to get all of the gear inside the fuse by making a tape-hinged hatch in the bottom. Internal heat seems fine for the moment but will monitor it after the motor upgrade. Hatch cover is secured by a big velcro pad as is the battery, both of which seem pretty secure.

Quote:
Has anyone tried this design in EPP?
Would have loved to try EPP but I'm yet to find a source in Perth. Luckily the state Depron supplier is about a 5 min trip from my house.

Cheers,
-Mat-
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Old Oct 18, 2011, 01:59 AM
Reap the wild wind
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Bristol,UK
Joined Feb 2007
3,963 Posts
Hi Wormboy
thanks for posting pictures. Nice idea with the eye decor. Those Magpies must be really thick to attack your plane with that large spinning prop it's running. But I think that's your problem. The Turnigy park 450 range max out at 1200 kv and are heavy at 60 grams. For better speed you need something in the 1800 - 2200 kv range running 7x5 -6x5 prop on 3 cells and weighing between 30-50 grams. What surprises me is that you don't have good vertical as your set up should be superior over a higher kv one.
I'm running a UK sourced version of this Himodel 1800 kv motor http://www.himodel.com/electric/1800..._A2208_12.html with a 1000-1500 3 cell lipo and 7x4 prop.
As an alternative you could try this motor from Target Hobby http://www.targethobby.com/hb2822-rc...p-4161589.html which I'm running in a larger Combat Wing donated by my brother. Much faster than the heavier motor/lipo combo he was running. He & my FB were so impressed that they ordered the motor themselves.
Check out their "Sprektrum" RX prices http://www.targethobby.com/rc-hobby-receiver-c-72.html
Look at the video and I think you will agree that it fly's very well on that Hi model clone set up.
http://www.youtube.com/watch?feature...&v=i7F8U8Afb-Y
Check out the vertical punch at 1 min and at 1 min 30sec. She will do unlimited vertical rolls. An absolute blast and flew her again on Sunday in winds that were blowing my 1.5 kg 48" BluCub over on it's back. Rock solid
Andy
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Old Oct 18, 2011, 03:13 AM
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Australia, WA, Madeley
Joined Jul 2011
645 Posts
Nice vid Andy,

Yeah, mine has nowhere near the performance of yours.
You're right about the heavy and slower motor, I think that one I have is rated at about 890kv so it's just not up to the task. As I said, it was just a scavenged motor that was lying around. Never really designed for the purpose it was put to.

Thanks for the links to the faster motors, I'll give them a look.

The maggies aren't really that stupid, they are surprisingly clever birds most of the year. Its just that in nesting season they all seem to fly around in a red-mist-of-hate the whole time. One moring I had them swooping me before I even got the plane out of the car.

I think they have also been a bit stirred up this year because there seems to be many more parkflyers now than ever before. Thankfully they will settle down again soon as thier chicks start fledging.

-Mat-
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Old Oct 18, 2011, 09:28 PM
CNC Cutter
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United States, IN, Indianapolis
Joined Dec 2005
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Jon, AKA jhtitan, has asked me to offer this model so guys would have a source for CNC cut parts.

To that end I have taken the design and created parts that will fit in my standard shipping box, a 18x18x2" corrugated container.
All glued parts are tabbed together and I will be cutting from 6mm white depron.
Foam Parts ONLY will be offered.

My current price point is $25 including S&H to USA customers.

I have it listed on my web page among my other offerings.

Still I wonder if the interest is really there, so I'm looking for input or reaction.

Thank for any and all comments and suggestions.

Bob
Northwest Cutout Service
http://www.balsabuddies.com/new.htm
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Old Oct 19, 2011, 12:53 AM
Reap the wild wind
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Bristol,UK
Joined Feb 2007
3,963 Posts
Hi Bob
So Jon followed up on my suggestion to contact you re kitting the Funbat. I'm sure you will have some interest from American customers but being in the UK would make the postage costs prohibitive. Perhaps you could offer a bulk buy discount for clubs wanting to engage in some streamer combat carnage?
Andy
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Old Oct 19, 2011, 10:05 AM
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United States, IN, Indianapolis
Joined Dec 2005
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Hey Andy,

Sure, I could offer qty discounts.

It would have to go FEDEX or UPS but still ...

I could do $116 for 6 ea versus $150 regular

or put another way $19.33 ea vs $25 ea.

The difference is mostly in the shipping and boxing.

I'll go put that up on my site later this AM.

Bob
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Old Oct 20, 2011, 01:11 AM
Reap the wild wind
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Bristol,UK
Joined Feb 2007
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Bob, I would suggest that any club buying with discount from you post some combat video on YouTube with a link to your site. The carnage might bring in some extra sales for you.
Andy
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Old Oct 20, 2011, 07:46 AM
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Washington MO
Joined Jul 2008
567 Posts
Thanx again Bob for adding the Funbat to your line up. I am going to send out a mass email to everyone that has emailed me lately asking when they will be available again. Hopefully that will generate a fee more sales for you.

Jon
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