Nice Piper L4 at Nitroplanes - Page 3 - RC Groups
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Dec 03, 2010, 05:59 PM
Registered User
Yeah, I noticed the jagged covering cuts on my plane, although not as bad as yours. Good thing I have a supply of #11 exacto blades on hand. I didn't open the bag with all the hardware. I'll probably end up using Dubro quick connects for the servos. My door is also slightly warped- nothing a few strips of basswood can handle.
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Dec 03, 2010, 06:58 PM
RC Paraglider / Sailplanes
Charlescd's Avatar
I can't wait to see if the power 32 will be enough. I was also thinking about that motor as i already have the esc.
Dec 04, 2010, 04:10 AM
Registered User
Ok so with the monster power 32, 4s 2200mah 20c pack, it pulled 480 watts at 34 amps. I hooked up a 5s 3800 may 25c pack just for fun and it was ridiculous. 980 watts at around 50 amps. I thunk the 4s is gonna be plenty though.

Oh and that was with the 12x3.8SF prop.
Dec 04, 2010, 04:14 AM
Registered User
Originally Posted by Melnic
Brandon, what props do you have to try?
12x3.8sf, 12x6sf and an 11x7e. That's all I have now. I'm sure I'll try a few more. But those are all I have at the moment.
Dec 04, 2010, 09:14 AM
Team Wack-a-Mole
Melnic's Avatar
yea, I don't think the SF props will like those RPMS. They start flapping in the air. Try that 11x7 on 5S. BTW, with the airplane slightly pitched forward, how much ground clearance for a larger prop do you have? Is that 12" prop the limit?
Dec 04, 2010, 10:15 AM
Registered User
480 watts should fly this plane great. It's light and has a pretty low wing loading.
Dec 04, 2010, 04:27 PM
Registered User
Originally Posted by Melnic
yea, I don't think the SF props will like those RPMS. They start flapping in the air. Try that 11x7 on 5S. BTW, with the airplane slightly pitched forward, how much ground clearance for a larger prop do you have? Is that 12" prop the limit?
With the plane sitting on three wheels the shaft sits 12" off the ground. With the plane leveled out and the MLG on the deck the shaft hits right at 10.5 inches. So even with the bird level there's still 4.5" of clearance with the 12" prop. So yeah there's some room.
Dec 04, 2010, 05:44 PM
Team Wack-a-Mole
Melnic's Avatar
sweet! thx brandon.
Last edited by Melnic; Oct 07, 2011 at 07:36 PM.
Dec 04, 2010, 10:00 PM
Registered User
No problem.

Today was a bust. Didn't get to go flying cause the site where we go was being used by those silly rocket guys. Anyway, we're shooting for tomorrow. So hopefully I'll have some super awesome flight video and a better understanding of what prop/battery combo is gonna work best.

Pretty excited about trying out my F-117 too!
Dec 04, 2010, 10:02 PM
Registered User
Forgot to mention that you may want to take into account the flex in the gear. If you land a little hard and the gear gives enough, I suppose you could smack the prop on the deck...
Dec 05, 2010, 11:38 AM
Registered User
Originally Posted by Melnic
...Try that 11x7 on 5S...
~40A, ~790W on this setup.

i may swap this setup into my Edge 540 and see what it does. this seems like a bit much for the cub.
Dec 07, 2010, 03:28 PM
Team Wack-a-Mole
Melnic's Avatar
Any update from the weekend?
Dec 07, 2010, 09:17 PM
Boogie_'s Avatar
Got all my windows glued in and the tail set up. I suggest doing the windows first. It's easy but a little tedious. On my scratch builds I like to get the unpleasant stuff out of the way first. It's easy to stay motivated with the fun parts.
They didn't design an air outlet into the kit so I may leave the large window out of the door to let air out of the cabin.

Motor and cowl all ready to go.
540 watts @ 50 amps
The wood prop is eatin' a lot of power but it's got plenty. At half throttle I was getting 250w and felt like it had enough pull to take off.

The 75mm wheels supplied with the kit looked small to me so I picked up some 3.5" Dubros. We fly off grass anyway so the bigger the better.

I won't have any servos until tomorrow. Other than that it's about ready to go.
Dec 07, 2010, 11:42 PM
Team Wack-a-Mole
Melnic's Avatar
Nice Pics boogie.
What Battery and what Prop?

I just bench tested my Monster Power 32 on a 3S and 4S battery.
13x8 APCe prop is what I had tried at first.
6400RPM and 320W max on 3S
7700RPM and 620W max on 4S

12x10 Wood prop was next
8400RPM and 520W max on 4S
These wattage/RPM values are on a fresh pack at about 90%charged (resting voltage around 4.0V)

This is pretty well in line (as one could expect) with the motor calc program I use:

I chose an Eflite 32, then set the motor to custom and changed the Kv to what I measured as 705Kv. I then set the battery to the Internal resistance I measured on my iCharger 106B+. Next Set the resting cell voltage to 4V (About what you get after the first 30-60 seconds of run up). Don't forget that your resting battery voltage will drop to around 3.75 at the end so I like some power in reserve.

I'd like to get some other props to try. Right now I'm leaning towards the 12x10 wood cause it will look better. I like the 7K-8K rpm range for this plane so the motor looks good with the 4S.
Dec 08, 2010, 04:29 AM
Registered User
looking forward to your other props.

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