Yeah, what Lenny said is so true. Even if you're uncomfortable with the idea now, after a short time you may be wanting more power. The nice thing is, provided you planned ahead, you could run a smaller prop initially and prop up later if you want.

Lenny, thank you, 10-15 seconds to climb - it's what I'm looking for right now.
Scot, yes I'm really uncomfortable now, but your words changed my mind a little bit.
Bigger prop and more cells are the only ways to increase power ?
I mean it will be impossible to change motor ?
I am going to choose power system that can be "stretched" from 500w to 800-1000w. I will try.
Thank you for help.

Sure, you can always change out the motor later if you want. Based on your initial desire to use the batteries you already have on hand, 4S 2650mah, try run calculations on an Neu 1110/2D with a 13x10 prop and then a 17x13 prop. Power is roughly 700 watts and 1300 watts with only a prop change. Maybe go to a slightly milder motor like a 1110/2.5D (400 watts and 1000 watts with the same props above) if you want a little less power. More prop or more cells will both increase power up to a point. One thing you need to consider if increasing cell count is max. motor rpm...Neu motors are safe up to about 60,000 rpm. I have a 1506/1.5Y that I was thinking about using. Looks a little better with the 17x13 prop compared to the 1110/2D.

Originally Posted by bastun

Bigger prop and more cells are the only ways to increase power ?
I mean it will be impossible to change motor ?

A good, cost effective way to start out with low power and have the ability to easily increase it later, is with cell count.

Select a motor/controller/prop combination that has a strong climb on 4 cells, and start out using a 3-cell battery.

Lenny

Originally Posted by Lenny970

A good, cost effective way to start out with low power and have the ability to easily increase it later, is with cell count.

Select a motor/controller/prop combination that has a strong climb on 4 cells, and start out using a 3-cell battery.

Lenny

Lenny is right on here..
The 1110/1Y/6.7 flies this model very well on 3S... I tried it. The 4S is what is in the video, and as you can see it give decent results.

Best,
Bob

Scot,
how can I change motor after I drilled and glued firewall ?

The motor just bolts onto the firewall from the backside so it's easy to switch later. Even though outrunners are popular nowadays, it's hard to beat a quality geared inrunner on a skinny nosed glider.

Oh, and Bob at Soaring USA has all the good stuff. He can tell you what you would want to use. Maybe he'll post some build pics of his plane so you can see the quality. Nothing like a beautifully made molded airplane. Hard to ever go back to balsa or foam!

Thanks for help, everybody.
Why are you using Neu 1110 and Neu 1506 and nothing in between ?
Neu 1112 and Neu 1115 ?

I'm just finishing up an Orion build. It's a very nice model but there were a few glitches along the way to watch out for.

The stock aileron and flap horns sit much higher above the wing than I'd like. Flap horn (measuring to the center of the clevis hole) was 5mm above the wing skin, aileron horn about 7mm above the wing skin. It looks like it may be difficult to get adequate flap travel with these horns. My preference is to have the flap clevis pin located very slightly above the wing skin and slightly forward of the hinge line. The aileron horn is less critical, but I prefer the clevis pin to be slightly above the wing skin and right over the hinge line.

I decided to modify the brass horns to bring the linkage closer to my preferred setup. In the picture below, you can see the metamorphosis of the horns -- I ground away the shoulder portion, redrilled a new clevis hole, and cut off the top of the horn. The resulting flap linkage is not quite what I'd like, but it's pretty close. As the pictures below show, I can get plenty of down flap travel and up travel (for mixing with ailerons) reaches the airframe's limits. The resulting location for the aileron clevis pin is a bit further back then I'd like, but that's not too critical. It just give a little "built in" differential.

The new MKS 6125 wing servos were installed for flaps and ailerons. The aileron servo wells are VERY shallow, but with the servos slid up against the spar the covers do fit. You'll need to use a very short aileron servo arm and be careful aligning the servo covers to make it all fit. If Hyperion DS-09's were used instead, the fit would be less critical.

Also, these servos are really nice -- strong, fast, smooth, slop-free, but be aware that they have less range of travel than other servos. This could be an issue for flaps, where you really need lots of servo travel. I was able to overcome this with some transmitter trickery, and was able to get just over 90 degrees of servo travel.

I did have a small issue with stab alignment. Sighting from in front of the model, it was apparent that the wing and stab were not quite parallel. It wasn't off by much, and would likely make no difference in flight, but it still bothered me. I spent about an hour massaging it back to straight, with the application of a tiny bit of CA and some careful filing.

Power setup is a NEU 1110/1Y/6.7, ICE Lite 100, and TP 4S-2250 battery.
Ready to fly weight is 61 ounces.
I've flown similar models that were over a pound heavier than this that thermalled great, so this one should be an awesome flier!

Lenny

Lenny,
Clean build!

B

Keep the Nan Orion pictures rolling. Gonna have to pick up one of these soon

Hey Lenny,
Thanks for the writeup and pics...nice and clean! Would you happen to know where it balances? BEC or rx pack?

Thanks Bob. I suspect that this will be a popular model.
It seems like a very nice balance between thermal soarer and warmliner in a convenient sized package.


Scot, This one runs on a BEC, but that's personal choice. A receiver pack could easily be added under the wing.
There have been varying reports of CG location for this model. It will start out at 90mm and be moved back from there as needed. The battery pack can easily be moved to adjust the CG.

Lenny

I am about halfway through my build. Should I plan on putting the receiver behind the servo tray? With whiskers? I thoughtlessly put the tray in the middle of the hatch opening. Consequently, I might have to move the tray to get enough room to access the fuselage.