PJD1

I built an electric ultimate biplane, and purchased a Tower Pro BMC 25A esc to run it from Raidentech. Their website indicates that you can set the cutoff voltage at 7.5V or 5V with a jumper switch. When the stuff came in there were absolutely no instructions for setting cutoff voltage or programming the brake on or off. I have contacted Raidentech at least 3 times for instructions and received no reply. Does anybody know how to set the cutoff voltage? I am using a 3 cell Li poly battery, and don't want to ruin it by discharging too far. Also, I am using a SK400XTmotor, which is way underpowered. It can bearly maintain altitude much less do loops, rolls, etc. Also, I had to add 84 grams of weight to the nose to achieve balance. My battery is only 1100 MAH, so i figure a larger battery up front will help with the balance. Any help on these issues will be appreciated.

opjose

The instructions are available on line...

I have the documentation that came with a Towerpro 60Amp Esc which pretty much worked for the 25A version.

Here is the link

http://www.hobbywing.com/upload/esc-e.pdf


You also may be getting poor output from the motor because the Towerpro ESC timing is not optimal for your motor.

This made a BIG difference for me... the ESC defaults to timing for the INRUNNER, which does not work very well.

The default cutoff is "medium", this is calculated as a percentage of measured total voltage (the ESC calculates the number of cells to use for this) and should be fairly safe.

Re: Weight

GET A BIGGER BATTERY!

Never add unusable weight to a plane if you can avoid it... I use the 1800mAh and 2200mAh that Nitroplanes sells, which work very well with this plane.

Who did you e-mail, Raidentech?

Did you purchase it through them or from Nitroplanes?

morespeed

i'm using the park 480 - 910kv and eflite 40amp controller, max amp 2100 battery
and 10 x 7 slow flyer prop.

gotta say this plane is great to fly, i'm having a blast with it.

crashinbash

My Feedback: (1)

Hi guy's, I'm soon to be a newcomer of biplanes since I looked at my girlfriends visa statement. I don't think I can wait till Christmas...... so now that I know what I'm getting I figure the sooner I buy an elect. setup the better. I've never flown any planes driving more than 2 servos, I have a parkzone brushless stryker and j3 cub but I do fly a number of 6ch helicopters. I've got a simulator and practicing on the e-flite ultimate which I can already fly patterns on pretty good after a few hours.

I plan on using this speed controller http://www.unitedhobbies.com/UNITEDH...idProduct=2164 , will it drive the 4 servos without a problem or should I get a ubec and separate battery? I notice no one else is really running a separate bec so I'm guessing it's not really necessary. With my hei's I only use a bec when the weights over 500g or using more than 3s batteries.

Also considering motors since I'm a newb to biplanes I was looking at this motor, http://www.unitedhobbies.com/UNITEDH...idProduct=3886 and using a low throttle curve until I'm comfortable doing more maneuvers. Is this way too much power with direct drive for this plane? or will I be ok if I'm driving the motor under 80% of it's potential power?

I'm going to use my 20c 1700mah 3s1p batteries and 20c 1800mah 3s lipo's I use in my helicopters for this plane

Thanks for any help

opjose

While you should be fine with the ESC ( Overkill with an ESC never hurts ) as the servos will at most only draw 1.5 to 1.8 A at worst....

The motor is a bit big for this plane.

The plane really only needs about 18A 250-350 Watts or so for almost unlimited verticals.

Heck I fly mine with a Frio which only draws 160 watts max.

You mention "throttle curve"... "this ain't no heli"... where that is applicable.

If you keep the prop size down though you will not draw more than 20-28A with say a 9x6E which is FAR more than enough for this plane.

texastomek

I flew my red ultimate for the first time today. I have a bit of an extreme setup: E-flite Park 10 motor and a 2100mah battery. This gives a short flight time < 10 min but provides LOTS of power. I do unlimited vertical at half throttle with a 11x7SF prop. This is a small prop for the motor, but any bigger and my bipe would counter-roll to the torque to the point of being un-trimmable. The plane is definitely not a trainer with this setup. It flies FAST and does not slow down for landing. I haven't weighed it yet because I don't have a small scale, but I'm sure it's considerably heavier than it should be.

I'm keeping the battery hatch door sealed with velcro. I also use velcro to keep the battery in place. I'm having problems linking the lower wing aileron pushrods from my servos to the horns. I used the little metal connectors on both the servo and horn sides of the pushrod but this is not giving me a stable connection. How did y'all make this connection???

opjose

I replaced the connectors.

I used "quick" connectors at the servo horn if I recall correctly and metal dubro connector clips at the aileron polls.



It sounds like you turned yours into a small missle!

texastomek

I have a LiPo charging question...

I originally bought the park-zone charger with built in balancer because it was cheap ($30). However, this charger is just weird - it gives me errors and it seems like it keeps charging indefinitely until I get tired of waiting and simply stop the charge. Thus, I want to get a better charger but I'm confused by the different options out there. I like the idea of GP PolyCharge4 (http://www3.towerhobbies.com/cgi-bin...?&I=LXKAU0&P=0) but I don't know if it balances...and if it doesn't, would I have to get 4 separate balancers to charge 4 batteries simultaneously??? This would make it unpractical. I'm also looking at the GP Triton JR (http://www3.towerhobbies.com/cgi-bin...?&I=LXMAH9&P=0) but from what I read, that doesn't balance either. I would have to get a balancer for that unit. And it only charges one battery at a time? Is that right? I'd be fine with this if I had no other choice. Also, can I directly connect my electrifly battery (http://www3.towerhobbies.com/cgi-bin...&I=LXMDN3&P=ML) to these chargers or would I have to but some sort of connectors?

What are you guys using? Please help!

opjose

Get whichever charger you want... I prefer the ICE charger over the Triton as it's slightly cheaper, and FAR more versatile...

It's ability to graph cycles ( so you can see the battery trend ) is very helpful, etc.

And then you stick one of these on: [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMGS7&P=ML]CLICK ME![/link]

The multiple battery chargers such as the Polycharge are very handing for field use when you want to charge multiple batteries. In this case you would need one of the above for each set of batteries you want to charge at the same time.

However the Polycharge is not very "smart". As such it has no provisions for doing the things that the ICE can do ( the triton does many of the same things though IMHO not as well... ).. such as testing battery capacity, battery cycling under load, NiCD deconditioning, etc.

So I purchased a Triton as my general purpose charger which I have hooked up to a converted 450 watt PC power supply, and then TWO Hobbico Quick field chargers ( each charges two batteries at the same time ) in a Goldberg Electro-Tote field box with a 27Ah sealed gel battery.

I have several Equinoxes which I use on either.

The Equinox will balance the battery as the battery is being charged. It goes between the charger and the battery pack.

jumper666

Acft: http://www.nitroplanes.com/pubrelulbiar.html

Motor: Scorpion 3008-32 http://www.rcdude.com/servlet/the-21...s-Motor/Detail

Prop: 10X7 or 9X7.5 prop data with Scorpion: http://innov8tivedesigns.com/Scorpio...32%20Specs.htm

AUW: with 2200mAh = 2lb 1oz with 1300mAh = 1lb 15oz

Enlarged servo holes so they could accept HS65-HB's

opjose

Looks nice, good combo too.

jumper666

opjose, thanks. If/when it ever warms and the winds die, we will see how she flies. Forcast in DAL/FTW area calls for cold, windy, with on and off showers for the next week. []

opjose

That sounds like our forcast for the next two MONTHS!

Ugh.

jumper666

Mine (post #60) maidened today. It went well. The Scorpion is a GOOD motor. Am considering another Scorpion for another build. Make sure to use a 20C or better battery. The 12C I used was okay but left something to be desired. Several have commented about the cg placement. Yes, it is as far forward as plans indicate. You might let it slip a tiny bit aft but not by more than a mm or two. Do everything you can to move weight forward. My battery is firm against the back side of the firewall.

opjose

I've flown it without problems with the C.G. set far MORE than a "MM or two" back.

I've flown it at the 60 & 70MM, though the latter is too much.

Hermann300

NEED HELP GUYS... I don't have the manual so I don't know where the CG location is... could you please let me know??

opjose

50-55mm.

Go for it a bit forward of that if you can... keep the ESC in the cowl area to help move the weight forward.

Make sure that the battery buts up against the firewall, all the way forward.

Of course this is not as problematic with a bigger motor.

Hermann300

Thanks OPJOSE.. but I've never had a biplane... so is it from the LE of the upper wing?
I am planning to use a 450m\, 20C ESC and 1320Mah... is this a good setup?

opjose

Yes center on LE of upper wing is correct.

A 450 motor should do fine, but a small 480 such as an equivalent to the E-Flite 480, will be perfect for unlimited verticals.

TerryE

My Feedback: (12)

opjose;

I just got my new baby, and need some help on motor selection. I have all three of these available in my parts bin, as well as a TP 2408-21.

I can run any of these motors on either 2 or 3 cells.

http://www.hobbycity.com/hobbycity/s...idProduct=2105

http://www.hobbycity.com/hobbycity/s...idProduct=2106

http://www.hobby-lobby.com/brushless-skatty.htm

Which of these would be best?

Thanks - I really appreciate the help. I don't really understand the various motor / LiPo combinations, or how to choose, so having someone with you experience to ask is extremely valuable. Thanks a lot for your help.

Terry

opjose

Ok let's see:

The A22-15M is 1050kV and can handle 16A operating 20A peak with a 10x5 prop.

A 3S Lipo battery is suggested... so...

20A x 11v = 220 watts.


At

11v x 1050kv = 11550 RPM's

You'll get around 50oz thrust or so at max.



The A22-20L is 1000kv and can handle 21A operating and 25A peak with a 11x5 prop.


25A x 11v = 275 watts.

You'll get around 68 oz thrust or so at max.

You'll have a higher power to weight ratio with this motor, but the prop size may be an issue.
You may want to go with a smaller higher pitch prop, say a 10x6 instead...


IMHO the Eskay 400XT is not powerful enough for this plane, so forget it.


The second motor is a bit heavier, but there have been people here having problems getting enough weight in the nose, so go for the second motor with the slightly smaller higher pitch prop.

You may want to look at getting something like a Kokam 3A2P 2000mA battery pack such as the 834374-3S... or the similiar 2500mA pack.

See: [link=http://www.kokamamerica.com/ka/rc.aspx]Click me![/link]

Why use one of these packs?

Because the battery is configured in a 3S2P arrangement, the battery is not as long as standard 1800mAh or even 2200mAh packs, but it is "wider" instead.

This lets you move the bulk of the battery weight forward towards the firewall to balance the plane, or also shove it back into the body.

There was one person here who obtained was unable to obtain C.G. figures because both his motor and battery were too light, and he could not move his pack forward any further.

I use a very similiar 3200mAh 3S2P 11v helicopter battery packs and this works great... ( rc-smart ) but they are no longer listed.

TerryE

My Feedback: (12)

opjose;

Thanks very much for the help. I will go with the larger motor, as you suggest.

Do you get to Leesburg at all? If you do, let me know and maybe we can go flying together...

Terry

opjose

Leesburg is a stone's throw for me.

I normally fly at the DC-RC field accross the river from you.

TerryE

My Feedback: (12)

Didn't even know there was a field over there - by Whites Ferry or Point of Rocks?

Edit: Just Google'd it - WOW, looks like a beautiful field. Paved runway and everything!

TE

opjose

Yup a very nice field.

The runway is on an elevated plateau.

New taxiways were added last year, and everything was just repainted and repaired.

The County built all of this.

We are a bit closer to Whites Ferry, but the field itself is north of Poolesville.

You can see it on the DC-RC web site map.

This saturday is supposed to be the official "opening day" though we fly whenever we can.

I hope the weather holds up, as I'm planning to be out there, hopefully with some new planes in tow.

I'm trying to finish my Polecat and put the final touches and adjustments on my new 50CC Edge 540T.

We have a lot of Jet guys around, though the field is never really crowded.