try to get some video!

Originally Posted by tuppertn

My EC5 connectors finally arrived yesterday and I now have everything soldered up. The initial spin up down in the basement blew all my foamies off their wall rack from across the room!

Ready to maiden at the first sign of reasonably calm air.

kendall

Man, this is a NICE flying plane...

Took it out today after the kids finished opening their presents. The snow was still pretty powdery so I opted for a ROG (ROS?) for the maiden.

Ground, er...snow handling was very good. It got airborne quickly and climbed out briskly before I even reached WOT with the stick. I had my CG pretty well forward for the maiden so I needed about 7-8 clicks of up elevator, but the rudder and ailerons were spot on. I quickly switched over to high rates after trimming. On the second flight I pushed the CG back to the recommended location and was able to take out about 4 clicks from the elevator.

It handles flawlessly and flies very lightly on the wing for a 7.5lb plane. Due to the high thrust line it had a slight dip of the nose when transitioning quickly to high throttle, but it was predictable, managable and could easily be mixed out in the radio. Stalls were straight ahead and predictable. The glide slope was exceptional and landings were slow and floaty. It's fairly aerobatic too. Fun plane!

And, yes, I got video...

Neptune Maiden.wmv (2 min 1 sec)

kendall

Congratulations.
Very nice! Nice flying and a nice video. Flies like a Seamaster should.

Joe

Originally Posted by bfaulguy

How much flight time is that setup getting you?

Now that I can finally answer this one...

I set my Tx timer for 8 minutes on each of two flights. Both sets of bats came back with a total of 18.9V (11.3 + 7.6). So 8 minutes burned 40-45% of the 4500mAh available. I wasn't shy with the throttle, but as you can see in the vid I wasn't blasting around at WOT either. If I wanted to push the packs I think I could safely get 12 of mixed flying or 15 minutes of easy cruising without worrying about the LVC.

kendall

Congrats!-What a great Christmas present! Thats some nice flyin-I am sooooo jealous. Can't wait to start on mine- but will have to for a while yet. Once again great job!

I've been working on a glow to gas conversion of a "Sea Monster" which os a Neptune knockoff, I think. I was thinking about flying it off snow also (Central Idaho Mountains).

Do you guys have any idea about the motor thrust line? I've got a couple of degrees of down and right, which is usually good for standard configurations, I just don't know about pylon-mounted motors. Any Ideas?

Oh that's really cool. Now you have me wondering whether or not to consider E power for my Neptune. I fly from a boat, so not having a big field box full of stuff and fuel onboard is a plus. I hate getting that oil on my vinyl . That, or I will wait until they come out with a true gasoline engine for this sized plane- still not digging the price of the large LiPos. BTW, that is an interesting way to set your antenna on the Spektrum radio, I'll have to start doing it that way to get rid of the weak zone. Thank you for posting that video!

Originally Posted by old rcer

Do you guys have any idea about the motor thrust line? I've got a couple of degrees of down and right, which is usually good for standard configurations, I just don't know about pylon-mounted motors. Any Ideas?

The thrust line on the Neptune appears to be zero degrees--no right and no down. I always start there anyway and see how it flies before I start messing with it. This one seems to fly great as is.

I would hesitate to put downthrust on a plane with a high thrust line. I'm concerned that it would make the nose-dip with high throttle situation worse. Regarding right thrust, the pylon puts the motor fairly near the aerodynamic center so I don't think right thrust would have as much of an effect as it would on a nose mounted tractor configuration. Just my thoughts. But I don't think it would hurt to try it and see.

kendall

Originally Posted by bfaulguy

BTW, that is an interesting way to set your antenna on the Spektrum radio, I'll have to start doing it that way to get rid of the weak zone. Thank you for posting that video!

As I understand it that's what the elbow in the antenna is for. Keeps the tx antenna parallel to the rx antenna(s) as much as possible while you're facing the plane. Makes sense to me anyway.

kendall

Hey Tuppertn- can you give us all your specs on your power system now that you've flown it. thanks Harold

Originally Posted by fairplane

Hey Tuppertn- can you give us all your specs on your power system now that you've flown it. thanks Harold

Sure.

• Scorpion 4020-12 (10.7oz, 542Kv, 85A/1500W max continuous)
• PolyQuest 30C 5S/4500mAh lipos (2S + 3S in series, 22.6oz)
• MAS 13x8 electric series prop (~990W)
• Castle Creations Phoenix ICE 75 ESC (with 5 additional 220uF 35V Rubycon ZLH caps and 18" 10AWG battery leads)
• AR6200 Rx
• 4x HS-325HB servos

That's all I can think of to give specs on.

kendall

Originally Posted by tuppertn

Sure.

• Scorpion 4020-12 (10.7oz, 542Kv, 85A/1500W max continuous)
• PolyQuest 30C 5S/4500mAh lipos (2S + 3S in series, 22.6oz)
• MAS 13x8 electric series prop (~990W)
• Castle Creations Phoenix ICE 75 ESC (with 5 additional 220uF 35V Rubycon ZLH caps and 18" 10AWG battery leads)
• AR6200 Rx
• 4x HS-325HB servos

That's all I can think of to give specs on.

kendall

Hey thats great! I would really like to electrify my Neptune but as stated earlier it is quite costly. Considering I have everything to go glow, but electric is so nice to fly from the boat. I see Hobbyking has some new lipos that can be charged at 5C . Just wondering how I can use these?
http://www.hobbycity.com/hobbycity/s...idproduct=9966

You could put 3 of them in series for a 6S setup if you really, really wanted to charge at 5C. Almost all of the 40C lipos on HC say they'll handle a 5C charge. There's plenty to choose from there.

kendall

Originally Posted by tuppertn

You could put 3 of them in series for a 6S setup if you really, really wanted to charge at 5C. Almost all of the 40C lipos on HC say they'll handle a 5C charge. There's plenty to choose from there.

kendall

Did not notice that! Thanks I will have to investigate further. So your neptune is running on 18.3 volts-is this correct? How do you determine what voltage you want to spec your system to?

Originally Posted by fairplane

How do you determine what voltage you want to spec your system to?

That's a whole thread in itself, bro.

Basically, once you determine how many watts you need based on the plane's weight and desired performance, you have to figure out the best way to get those watts. Since watts = amps x volts, the higher the voltage you use the fewer amps you need to draw to get the same power consumption. You can get 1000W from a 3S setup (~11.1v) but you need to draw 90A to do that. Using higher voltage is a more efficient way of using electricity (ie - it reduces loses due to resistence). So it's more efficient to get those 1000W from a 5S (18.5v), 6S (22.2v) or even 8S (29.6v) setup drawing only 54A, 45A or 34A respectively.

So it's partly a matter of preference, partly a matter of what gear you may have on hand, and partly a matter of planning for best efficiency. It may seem complex, but that complexity reflects the fantastic veratility of an electric setup. With the same motor and ESC I'm using now I could give this plane anything from 375-1500W. I can give it gobs of low-end thrust and have it launch vertically out of my hand or have a top speed over 85mph all just by changing the battery and the prop.

kendall