TManiaci

My Feedback: (6)

c016Y,

Sure... look at these Lipoly's as good choices.

The only ones at Tower that look good are:

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKAP9&P=7]Apogee 3-Cell 11.1V 1570mAh[/link] is a good choice, Weight: 3.8oz, 10.5C, 16.5 Amp cont., 22 Amp Burst, $66.

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLPC8]FMA Direct/Kokam CELLPRO 1250mAh[/link] is a bit heavier, stronger, but shorter fly time. Weight: 4.13oz, 15C, 18.75 Amp cont., $46.

Other (better) Choices:

[link=http://www.rc-dymond.com/order_batteries_lipol.htm]Dymond HD 3S 1500 mAH[/link] is a great value. I love these batteries, great quality, light and CHEAP! Weight: 3.4oz, 12C, 18 Amp cont., $39. (stock #22748)

[link=http://www.rc-dymond.com/order_batteries_lipol.htm]Dymond HD 3S 1800 mAH[/link] is a nice choice. Strong, fairly light and great value. Weight: 3.9oz, 12C, 21.6 Amp cont., $41. (stock #22809)

[link=http://www.hobby-lobby.com/thunderpower.htm]Thunder Power 1320 mAh "Pro Lite"[/link] is a perfect lightweight powerhouse. Weight: 2.9oz, 13C, 17.1 Amp cont., 26 Amp burst, $55. (stock #TP13203)

Many others are in this class with various online stores. Look for specs in the range I selected here, where mass is less than 4 oz's and continuous current delivery is at least 15 amps. You can "expect" 12-14 minutes airtime from the 1500 mAh capacity range, depending on how hard you fly. The 1250 mAH will only fly for 7-10 minutes, and the 1800 mAH will get you a solid 14-16 minute fly time.

Battery selection is a "budget and style" decision. If you want great 3D performance, go lighter with lower mAH with big "C" ratings and give up some on fly times. If you are a speed demon wanting big powerful climbs and long flights, go for bigger mAH and big "C" rating (expensive). Then, balance that with a budget and buy it. If you are a beginner, heavy is good for stability in wind, so look at bigger mAH with moderate "C" ratings to save $$$.

c016Y

I hope I am not making a mistake getting the yak (flex like the ucd). I am not a beginner at all. I just have not done electric however. I am looking for something fun that can do 3d in the backyard, but, wanted to really push it w/o breaking it as much. They appear to be really good fliers especially if you put tape down the side or the cf rods. cumn thru was talking about putting packaging tape down the side and making it stronger that way. So it would flex if it had to, but, nothing perminent. Do you think this is a plane that would just really disappoint someone who has been 3d'ing for a while?

I think I am going with
Yak ep
Hitec Micro 05S
Dymond HD 3S 1800 mAH (wanted the longer flight times)
5 Futaba S3108 Servo Micro 7.6g http://www2.towerhobbies.com/cgi-bin...42&FVPROFIL=++
A20-20L w/Hacker X-20 ESC

This will still hover with decent pullout won't it?

btw.. thank you SOO much for your help.

and sorry for posting yak questions on ucd ep forum everyone. I think the power plant questions would closely apply to both however since they are close to the same weight and both flex.. there are just not many people on the yak forums.

TManiaci

My Feedback: (6)

c016Y,

I am no 3D master, by any measure. Still learning (and crashing) myself. But, I will say that the "mushy" response of the UCD will probably dissapoint a hardcore 3D pilot, even with the stiffening efforts. The wings flex out past the spars (1/2 wing) when you do hard walls, and the tail twists in snaps and other stick slamming stunts. I have not seen the Yak fly, so I don't know if it's the same.

We got the UCD for the same reasons, push the limits and crash without major repairs. Frankly, it doesn't excite me much, but I don't need to fly in a very confined space either. My favorite (and best I've seen) is the E-Flight Yak 54. Big thread on it [link=http://www.rcuniverse.com/forum/m_2828536/anchors_2828536/mpage_1/key_/anchor/tm.htm#2828536]HERE[/link] for mods and setup. This plane is stiff, and does it all with grace and authority... but... it's a depron confetti bomb when you crash it. I'm on my third. It's an awesome practice platform for the nitro or gasser pilot.

That setup is perfect. It will pull out with authority on a 15 oz plane. If you want to work on keeping it light, Dymond has an awesome [link=http://www.rc-dymond.com/order_servo_dymond.htm]D47 Micro Servo[/link] with 20 in-oz and 0.1 sec., and it only weighs 4.7 grams. These are really nice German made imports. The olny downside is the arms are short, so you'll have to extend them to get big throws.

c016Y

I am no 3d master either.. got pretty good at harriers with my ucd .60 and even rolling harriers. That plane is crashed and got a f90.. anyways..

I am hoping this plane will make me a better pilot. It seems that the "mushy" response might actually be good? Make it fly more like the big ones. I am not flying this to be good at quick little jetty foamies.. I really just want practice for my funtana 90 and katana 36%. What do you think about the fact that this is mushy maybe flying more like the bigger ones? Is that right at all. The big ones don't seem like they would react as fast. I have no idea.. have not flown a single foamy to compare. That will be all of the questions for today. Just want to make sure I am not making any mistakes.

TManiaci

My Feedback: (6)

c016Y,

I fly the F90 too, Saito 150, and the E-Flight Yak flies a lot like it, only scaled down. Wish I had a 36% anything... I have the gasser thirst, some day... maybe next year I'll cough it up and get one.

Mushy... well, it's hard to describe. The F90 does crisp stunts, very predictable, exits are clean and smooth. The UCD seems to come out of stunts in peculiar ways, I think due to the flex. You get used to it, but it is different from rigid airframes. It's not that bad, but if you get crazy, it gets a little unpredictable. Even pattern flight is different. Not really sure what it is, but just unfamiliar is the best way to describe it.

I hate the little flat-out foamies. Particularly the bipe's. They are so snappy and agile, nothing like a larger plane. And, you can't fly with much wind either... I've had a few. You won't be totally dissapointed, particularly when you plant the spinner. That's when you'll be happy that 10 minutes later you are flying again.

c016Y

Great info.. thanks tman

Towers

Where can I buy the TP 1320mAh 15C 3S?... by hobby-lobby?
The problem is that LiPo batts are now restricted to air (international) shipping do you know if hobby-lobby restricts lipo´s shipping???
Thats my new concern....

Towers

What is the "sensorless" thing on some ESC´s???
The sensorless ESC is compatible with every brushless motor???

The E-Flight Yak 54 that you talk about earlier is available on what website??? and what set up do you recommend? ( as you are on ur 3rd one, I think is a really, really good value!)

TManiaci

My Feedback: (6)

You can buy the Thunder Power batteries at many websites like Horizon Hobby, Wholesaletrains and Hobby Lobby, among others. Google "Thunder Power" and go surfing. Somebody probably will ship them, but you may have to call them to ask.

You can get the E-Flight Yak 54 at Horizon Hobby [link=http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=EFL2125]HERE[/link].

I'm not sure about the "Sensorless". From what I can tell, it appears early brushless motors had a sensor that connected to the ESC for speed feedback. As far as I have seen, all of today's ESCs are now sensorless.

TManiaci

My Feedback: (6)

Towers,

We (my son and I both) have the Yak54, equipped with the AXI 2212/20, CC Phoenix 25 Amp ESC and Dymond HD 3S 1500 mAH 12C turning an APC 10x3.8. It is VERY strong and a blast to fly. We overload the battery a little at WOT, but it seems to take it in stride. We just keep the WOT runs short.

We have two Dymond HD 2100 mAH 12C batteries that we fly in them for fun when it's a little windy, or we want to fly to the moon in a hurry. The vertical perfomance is so incredible at over 21 Amps, ~230 Watts, you just laugh as it blasts off and gets tiny climbing into the clouds. It's enough power to fly a 25 ounce plane well, so on a 15 ounce plane it's just way crazy. I Like!

Henli

[8D]Towers, Get a job, don't bother busy people! jajaja

I've got all your answers, you know how to find me, my friend.

Say hello to Jit.

See you soon.

Henli

I recently got an Amo 20 size Electrifly brushless motor, Does anyone know if it works with the Electrifly A25 ESC Silver Series? or Do I have to get an specific sensor less ESC by a different brand. Is it gonna work?

Thanks for your help.

TManiaci

My Feedback: (6)

hsolis,

Electrifly site seems to make no special notes about ESC requirements. Looks like it will work fine.

Henli

Thanks Tman.
Do you think this configuration will work with a Great planes yak 55 for a good 3D?

TManiaci

My Feedback: (6)

hsolis,

What is the Kv on the Ammo 20?
What gearbox ratio do you have?
What battery do you plan to use?

It should be okay, but not ballistic. The motor Kv (rpm/volt) needs to be matched to the gear ratio to turn the a 9-10 inch prop at 7000-9000 rpm. You can see Jason Noll fly a 12-13 oz Electrifly Yak 55 on an Ammo 20 motor, but they don't tell you which Kv or Gear Ratio.

Towers

Tman,

I have another question about electric...
I have an electric motor, (guessing is a brushed one because it has only 2 wires) I dont know its name or rating... (i found i on my stuff) the motor is kind of big...
it has 4.5 cm (aprox.) from the backplate to the front...
also 3.2 cm of diameter....
I tested it with a 9.6V 700mah Ni-Cd 8 AA´s pack... it runs pretty hard and fast
Knowing the power that it has I would like to put it on a plane....
I have a Electrifly Brushed C-35 mini ESC 6-12 Ni-Mh/Cd and 2-4 lipo...
I wonder if using that ESC with the motor, would represent a risk of damage for the ESC???

TManiaci

My Feedback: (6)

Towers,

Too many unknowns there. You either need the motor specs, or a Wattmeter to test loads. I would guess the ESC is 35 amps, that's pretty strong. The battery may be too small, and you don't know what prop to put on without better information or measurements.

Towers

Yeah I know.... its just uknown....
But it would be a good idea to conect and test the ESC, or it could by dangerous for the ESC???
I am concerned about the ESC "health" its the only one I have but since Im going brushless it would be stored because i have no other EP plane (just starting)....
I guess a Watt-meter is a very good tool for electrics but i dont know when i can get one...

But thinking about it... mesuring RPMs with the stock UCD EP prop.(11x4.7) on the motor would help on guessing any aprox. specs of the motor???

Henli

TMan,
Thanks for answering. My Ammo Motor is a 20 size 5100 Kv, my battery is a 3 cell li-po 1500 Mah Kokam and Gear Box is the one that comes with theGP Yak 55, I thinks is a 5:1.
I'm using a 10x4.7 Apc prop, What do you think is it gonna work?


HSolis.

TManiaci

My Feedback: (6)

Towers,

I doubt there is any risk to the ESC. The bateries won't deliver enough to overload it.

~~~~~~~~~~~~~~~~~~
hsolis,

It sounds too hot. 5100 Kv @ 11 volts will turn 56,000 rpm, and final rpm will be ~11,200 rpm with 5:1 reduction. That's too fast, so it will draw very high current levels with such a big prop. You will need to gear it down to under 9000 rpm (6.5:1 or more) or go way down on prop size, maybe 8x4.7 or 9x3.8 I would guess.

Again, it's all guesswork without a wattmeter. You can put it all together and bench test it if you can't get your hands on a meter. Run it Wide Open Throttle (WOT) for 10 seconds. If any of the components are getting pretty hot, you need to change the gearing (higher ratio) or prop (smaller diameter and pitch). If it's not hot, let it cool off and recharge, then run it 20 seconds, and check for heat again. If it's hot then, smaller change is necessary. If you can step up in small increments until you can run it WOT for a solid minute without anything getting really hot, then fly it. I feel pretty sure the 10x4.7 is too much prop for this setup.

What is hot? If you can't hold you fingers on a component, it's too hot. That applies to the Motor, ESC and the Battery. This is a cheap way to check for overload, but it works. Hot means overload, simple as that.

Another test you may be able to run is with a voltmeter. If you can get one, hook it across the battery. When the battery (3 cell Lipoly) is fully charged, it should be 12.3-12.8 volts. If you set up well, the battery should not fall below 10.5 volts at WOT for at least 10 seconds. If it does fall below 10.5 volts, change the gear ratio or put on a smaller prop, recharge and test it again.

Towers

Thanks, TMan thats a relief.. as soon as the brushless gets here i would be considering the ESC installation on the motor

Thanks, you´ve given me a lot of help!!
Thats to be appreciated!

Probably I would bothering you[:@] with more questions since i have a lot to learn!

Henli

Thanks TMan, You're the person that I was looking for.
I will be testing my motor prety soon and I'll let you know the results.
Thanks again, I'll appreciate it.

HSolis.

Falcon26

Have one Love it built nice it when I first took it to the field it was a touch windy for it 10 -15 (no hovers) but fast rolls inverted circles nice in and outside loops climbs nice powered by a polyquest 3cell 1500 (10c) the flex fly part takes a little to get used to. Turns and lateral force tend to carve for lack of a better word you feel a little lag or delay on control input but it does what you tell it quite nicely the fact that when you held it and moved it side to side it made the tail look like a fish swimming had all the club member's shy away from giving it a try bounces aren't totaly for free you should have a few extra noses and tooth brush to clean the grass and dirt off the gears

The next time much better day lower wind was able to trim it out and set CG (start mild and work up to as good as it gets) it flys as good as they say after a few flights a few of the other flyer's gave it a whirl still leery about the fish thing but none dumped it all had fun and the biggest yuck of the day was when was the last plane you ever flew with a zipper (DON'T EVER FLY WITH YOUR FLY OPEN)

It will not survive a strait in blast under power but it does survive dumb thumbs and will help you learn
to fly and do things with more comfort and fun

Towers

Well I finally flew my UCD with the Rimfire and 8amp ESC, and it was great!!!! half throttle to roll, snap, loop and 3/4 to hover (although I can maintain hover too much) and full throttle if you want some vertical performance... Although Tman said that set-up would be running very hot... I decided to mount the ESC on the outside of the fuselage and cut a inlet hole directly on the batt. and after flight, none of the components where even hot....the day was windy but still my UCD flew stable and fast!!! with the upgrade the plane is the one that flies on the wind not the wind on the plane.... i highly recommend to change the stock motor it is a BIG difference and BIG fun, too-----

ca$hey

TMan still haveing fun with yak,but i also have picked up one of those flexy ucd,i thought it would be agood practice plane but after reading these threds im not so sure ihavent put anything together yet iwonder if you could give me your expert tips on building this plane i know you have posted them allready but some threads are old, by the way do you still fly the u can do cheers beaggs