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Old Mar 25, 2012, 11:41 PM
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Boise, ID
Joined Dec 2008
1,102 Posts
Hi diggity,

Thanks for the advice.

I think the CoG was the issue, either because I messed up with my careful measurement of it, or the battery came loose and shifted, at takeoff or in flight.

My expo was 20%. As I think more about it, the plane was struggling to fly, and it's erratic movement, especially with extreme aileron movement, was nothing like the way my Aspera flew.

My battery weight wasn't the issue, I don't believe, because my battery is well within the recommended range. 3D HS manual recommends 4S 2200 - 3000 mAh batts, and they can weigh up to 364 grams, that I've found, researching on line. My Thunder Power ProLite 3S 4350 mAh weighs 310 grams, almost two ounces less. The Turnigy 4S 2650 weighs 296 grams, which is only 14 grams, or .5 oz., less than my battery. Those Thunder Power ProLite's are great, if you haven't checked them out. Very light, per capacity, compared to most others that I've researched. That's why I fly with them, and I used them with my Aspera, which had no problems with it. I also fly them in smaller planes, and again, with no problem. They're great, and provide long flight times at a very flat power curve.

The distribution of that weight, however, is another matter, and that's where I think my problem was. Very discouraging, as I thought I'd carefully checked that CoG. Maybe the battery slipped somehow and threw things off. Maybe I put the batt in upside down, so the velcro patch didn't meet the velcro strip on the battery tray. This whole crash is very discouraging, actually, given the care I put into building this bird. Bad CoG was the LAST thing I would have thought would produce a crash.

Anyway, I'll contact 3D Hobby Shop Monday about spare parts.

Thanks again.
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Old Mar 25, 2012, 11:54 PM
Registered User
Boise, ID
Joined Dec 2008
1,102 Posts
Hi Danamania,

Thanks very much for that advice. I had completely forgotten about plus and minus exponential, and immediately checked my transmitter. And the manual. It's a DX7, and it was set to +20% exponential. DX7 manual states " "Normally a positive value is used to desensitize control response around neutral."

So, expo was set ok, whew.

Which leaves CoG as the cause, I'd say.
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Old Mar 28, 2012, 12:41 PM
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Boise, ID
Joined Dec 2008
1,102 Posts
Wow, 3D Hobby Shop ships fast. I called them Tuesday, mid-day, and they had shipped the cowl and wing tube within the hour. Other repairs are coming along. Osiris will fly again, maybe this weekend!
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Old Apr 01, 2012, 07:12 PM
It's just a plane.
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USA, SC, Goose Creek
Joined Aug 2010
2,104 Posts
My red Osiris is still stuck up in the tree -- well parts of it are anyway. I'm afraid she's a goner at this point. I do have a canopy if anyone wants one cheap. It's for the red version. If interested shoot me a PM and we'll work out a deal.
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Old Apr 03, 2012, 12:54 AM
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stuntflyr's Avatar
Los Angeles
Joined Jun 2010
1,316 Posts
Free Flight guys always have long telescoping poles for freeing thier models, know anyone local?
Chris...
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Old Apr 03, 2012, 08:17 AM
It's just a plane.
ZackJones's Avatar
USA, SC, Goose Creek
Joined Aug 2010
2,104 Posts
Quote:
Originally Posted by stuntflyr View Post
Free Flight guys always have long telescoping poles for freeing thier models, know anyone local?
Chris...
No and it's a good ways up there. When I checked it Sunday the wing is on one half of the branch and the fuse on the other so it's hanging by the servo wire.
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Old Apr 09, 2012, 02:00 AM
Fly Fast!
dbgood's Avatar
scotia ,NY
Joined Jul 2008
627 Posts
eflite power 15 in Osiris 47

Hi guys,
I think im gonna order a Osiris 47 this week sometime,the blue version.
I have lying around a Eflite power 15,its a 950 kv,i run the same motor in
my eflite ultimate 20-300 bipe,on 4cell and a 60amp speedcontroller,its a very fast bipe.
I was wondering if the power 15 would fit in the Osiris,i know the motor is 50mm long,maybe a bit to long to fit in the Osiris,has any one mounted this motor in theirs?
I didnt look through all the posts to find out..
Also what kinda speeds are these capable of?
They look pretty quick..
Thanks,
DB
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Old Apr 09, 2012, 07:40 AM
Wingman II
diggity2424's Avatar
United States, KY, Louisville
Joined Sep 2011
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might be to heavy.
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Old Apr 09, 2012, 10:50 AM
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mjb_18's Avatar
United States, IL, Antioch
Joined Feb 2008
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Quote:
Originally Posted by dbgood View Post
Hi guys,
I think im gonna order a Osiris 47 this week sometime,the blue version.
I have lying around a Eflite power 15,its a 950 kv,i run the same motor in
my eflite ultimate 20-300 bipe,on 4cell and a 60amp speedcontroller,its a very fast bipe.
I was wondering if the power 15 would fit in the Osiris,i know the motor is 50mm long,maybe a bit to long to fit in the Osiris,has any one mounted this motor in theirs?
I didnt look through all the posts to find out..
Also what kinda speeds are these capable of?
They look pretty quick..
Thanks,
DB
Yikes - i have that plane as well as interest in the Osiris. However, I have the Power 10 in my bipe. That thing must really cook with a 15 in it.

My primary interest in the Osiris is it's versatility...and I gotta admit the video on their website sealed the deal for me. Now to find some $'s...
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Old Apr 09, 2012, 03:23 PM
scratch-built
Jim Lee's Avatar
United States, WA, Port Orchard
Joined Apr 2007
1,001 Posts
dbgood,
Your Power 15 would be too long to fit the cowl space. I have a Omega 130g 870Kv that is 45.2438mm and it just does fit in the cowl space. If your Power 15 is 50mm, You would have quite a gap between the front of the cowl and the spinner.

The Power 15 would probably fly the plane, but it would be marginal on power. The weight would be ok, but you wouldn't have any excess power.

The three motors that 3DHS recommends are the Omega 130g 870Kv, The Torque 2814-820, and the Hacker A30-14L. You should use a motor that is close to the specs of these motors or use one of these motors in your 47" Osiris.

I favor the Omega 130g 870, as it's the easiest motor to mount in the available cowl space, It also has plenty of power. I'm flying mine on a 11x8e APC Prop, a 4s 30c 2650mAh Lipo, 50A ESC and I'm getting about 630 Watts in.

J
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Old Apr 09, 2012, 10:19 PM
Fly Fast!
dbgood's Avatar
scotia ,NY
Joined Jul 2008
627 Posts
Quote:
Originally Posted by Jim Lee View Post
dbgood,
Your Power 15 would be too long to fit the cowl space. I have a Omega 130g 870Kv that is 45.2438mm and it just does fit in the cowl space. If your Power 15 is 50mm, You would have quite a gap between the front of the cowl and the spinner.

The Power 15 would probably fly the plane, but it would be marginal on power. The weight would be ok, but you wouldn't have any excess power.

The three motors that 3DHS recommends are the Omega 130g 870Kv, The Torque 2814-820, and the Hacker A30-14L. You should use a motor that is close to the specs of these motors or use one of these motors in your 47" Osiris.

I favor the Omega 130g 870, as it's the easiest motor to mount in the available cowl space, It also has plenty of power. I'm flying mine on a 11x8e APC Prop, a 4s 30c 2650mAh Lipo, 50A ESC and I'm getting about 630 Watts in.

J
If i could fit it,the power 15,on 4S the Osiris would be really quick plane,its a 950kv on 4s...But since its to long to fit i'll go with another motor that they recommend..
How fast would you say the Osiris is on 4 cell,and a 11 inch prop and 870KV motor?
If i can i would even run it on 5s..
Thanks for the help,
DB
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Old Apr 10, 2012, 06:13 AM
Advocating for RC Aviation
USA, NJ, Phillipsburg
Joined Jul 2010
1,390 Posts
Now would be a good time to post the prop calc link. It is a helpful, free, tool to figure out things like prop size, airspeed, motor choice, etc. Fun to play with too! Enjoy!
http://www.ecalc.ch/motorcalc_e.htm?castle
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Old Apr 10, 2012, 06:16 AM
It's just a plane.
ZackJones's Avatar
USA, SC, Goose Creek
Joined Aug 2010
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Quote:
Originally Posted by dbgood View Post
How fast would you say the Osiris is on 4 cell,and a 11 inch prop and 870KV motor?
Very. Fast enough that you can point it vertical give it full throttle and it will literally climb until you can't see it. I really hate going to the flying site now and seeing what's left of mine still stuck up in the tree
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Old Apr 10, 2012, 08:27 AM
Fly Fast!
dbgood's Avatar
scotia ,NY
Joined Jul 2008
627 Posts
Quote:
Originally Posted by ZackJones View Post
Very. Fast enough that you can point it vertical give it full throttle and it will literally climb until you can't see it. I really hate going to the flying site now and seeing what's left of mine still stuck up in the tree
Ok so i ordered the omega 130g,870kv for my plane.
Also have a 11x8.5 apc prop,and on the motorcalc,it
says prop may stall
hope it will be fine..
DB
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Old Apr 10, 2012, 09:58 AM
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Neil Morse's Avatar
San Francisco, CA, USA
Joined Jul 1999
6,124 Posts
Quote:
Originally Posted by dbgood View Post
How fast would you say the Osiris is on 4 cell,and a 11 inch prop and 870KV motor?
I'm running the Torque 2814-820 in mine on 4S 2500 packs. With an APC 11X7 it was a bit too fast for my liking. I switched to a Xoar 12X6, and I like it better. A buddy had his radar gun out at the field a few weeks ago, and the Osiris was clocked at 70 mph on a straightaway low pass. (Also did 70 inverted, which was fun!) I love the plane, and it is really helping me to hone my precision skills.
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