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Old Oct 19, 2015, 05:31 AM
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Help!
Olympic ii e-power conversion

Hi all,

I snapped up this old glider for a really good price. I believe its an Olympic ii (correct me if i'm wrong). 2.55m wingspan (and as an inconvenient 1 piece). Rudder, elevator and spoiler controls.

Its in pretty good shape. The wing, apart from being 1 piece, doesn't need much work to it. The fuselage has some issues at the tail and needs some recovering.

Now, the thing is: I want to mount a motor and folding prop up front. I need some idea of how much power to aim for? The weight as is (no electronics and only servos in the spoilers) is1073g (or 2,37lbs), which does seem a bit heavy already, i am maybe wrong. For a bird this size whats a good auw weight to aim for (including of course a power train)? If it is an Olympic ii the wing area is listed as 59.9 dm sq.

then also, on a side note; the plane cam with this circuit board device strapped to the tail, the seller didn't really know what it was but suggested its a component of some kind of old style stabilization system. Just for interest sake, any idea what it is? (there's a pic of it below)
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Old Oct 19, 2015, 05:44 AM
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Here's a link to photos of my OLY IIS build, which I electrified. The photos of the motor installation may be of help.

https://www.flickr.com/photos/312210...57639149983546

I used this HobbyKing Glider Drive motor and have been very pleased with the result:

http://www.hobbyking.com/hobbyking/s...3_5_960kv.html

ESC is 40 amp, prop 12x6 folder and a 2650 3S 40C battery.

Interesting looking circuit board taped to your plane- I have no idea what it might be. Do let us know what it is when you find out....
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Old Oct 19, 2015, 10:48 AM
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Quote:
Originally Posted by 2400RDR View Post
Here's a link to photos of my OLY IIS build, which I electrified. The photos of the motor installation may be of help.

https://www.flickr.com/photos/312210...57639149983546

I used this HobbyKing Glider Drive motor and have been very pleased with the result:

http://www.hobbyking.com/hobbyking/s...3_5_960kv.html

ESC is 40 amp, prop 12x6 folder and a 2650 3S 40C battery.

Interesting looking circuit board taped to your plane- I have no idea what it might be. Do let us know what it is when you find out....

Great, thanks for the link, its a awesome build that. What was your auw? Also how much motor time do you get with that setup?

That power train is actually far bigger (in terms of weight and power) than i was anticipating.
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Old Oct 19, 2015, 10:52 AM
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Just my 2 cents worth.. I've pretty much standardized my woodie power set up. I've built just about all the sky bench kits including all the olys. I settled on the glider drive 840 currently have 9 of them with no problems noted. I use a 12/8 folder and run a 60 amp Esc. You don't want to scrimp on your Esc size or quality because if it is over amped and fries your going to turn your oly into RTKF ( reduced to kit form). Battery is your area for adjusting CG, I prefer a 4s because of the 30 second/200 meter rule in ales. I also go with hobby king nano tech batteries with at least a 70 c max again because of the full power run to 200 meters. I wouldn't worry about the weight issue olys fly fine and the weight helps in the wind. Just get the CG right and you'll have a ball. I've always made the 200 meter limit under 30 sec. with this set up ,but the bigger birds Like the challenger at 154 inch span do require a different set up. Lastly dump whatever that thing is in the back.
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Old Oct 19, 2015, 12:51 PM
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Quote:
Originally Posted by lFritZl View Post
Great, thanks for the link, its a awesome build that. What was your auw? Also how much motor time do you get with that setup?

That power train is actually far bigger (in terms of weight and power) than i was anticipating.
I never weighed it, nor have I worried too much about the motor run time because I don't do competition. Depending on the conditions, I may do as many as four or five climbs to 500' during a single flight, and after doing that come home with the battery at about storage voltage (~3.8v per cell)

The completely accidental beauty of my setup is that the weight of the motor and other stuff in the front compartment made the OLY balance perfectly on the CG with no added weight anywhere, and without a battery. Since the battery sits exactly over the CG in the under wing compartment, the outcome is that I can use any weight battery without affecting CG, and minor adjustments to CG can be made merely by moving the battery fore or aft. So- you may find the weight of such a setup beneficial.
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Old Oct 19, 2015, 01:35 PM
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Ok, i appreciate the input a1jrocket.

Seems like these glider drive motors are popular. I don't need competition level performance, so here's what I'm thinking the 960kv glider drive, 12x6 folding, 45A and 3s 2200 40c (purely because I have several of those batts from my 450 heli). If i roughly tally that up with my receiver and servos i get 1450g, that gives a wing loading of 24.8 gm/sq.dm ? I need something to compare that to.......??
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Old Oct 19, 2015, 01:59 PM
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My first e glider was an Olympic II. It was a wonderful g as bag glider. I was un sure of the e power at first, so I added a power pod above the wing. It worked, but I was not happy with the changed in handling caused by higher center of gravity.

I chopped the nose off, fixed a 1/4 plywood firewall and put the battery under the wing. As you found, then I could run my choice of battery without balance issues.

Nose mounted motor was brushed with planetary gear box, until I discovered brushless. The Oly II does not need 500 watts to climb on. My wings were prone to flutter at full power.

Easy conversion and fabulous flyer. Use the prop turning over very slowly to achieve air brake. Shut motor off before landing.
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Old Oct 19, 2015, 03:37 PM
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Originally Posted by JimNM View Post
My first e glider was an Olympic II. It was a wonderful g as bag glider. I was un sure of the e power at first, so I added a power pod above the wing. It worked, but I was not happy with the changed in handling caused by higher center of gravity.

I chopped the nose off, fixed a 1/4 plywood firewall and put the battery under the wing. As you found, then I could run my choice of battery without balance issues.

Nose mounted motor was brushed with planetary gear box, until I discovered brushless. The Oly II does not need 500 watts to climb on. My wings were prone to flutter at full power.

Easy conversion and fabulous flyer. Use the prop turning over very slowly to achieve air brake. Shut motor off before landing.
.... My first thought, before i had bought the plane was that something like a higher kv 480 on 2s would be sufficient. While that might have been a bit under powered it shouldn't need more than 300W should it?

The glider drive 960 comes in at 309 W on 3s (see pic below). Bit heavier than i hoped, but its a proven setup (by 2400RDR) at least.
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Old Oct 19, 2015, 03:39 PM
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That ought to do you just fine. Too much Pitch speed is more of an issue than actual thrust.

You just cannot fly and old gas bag claim that fast. I try for at least 3x stall speed for my sport planes. On the Oly II, 2x stall speed will be fine.
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Old Oct 19, 2015, 03:57 PM
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...... As for that circuit board on the back, I googled the name on the components. Turns out its an IR sensor array, and as the seller of the glider suggested, its part of a stabilization system called: Co-Pilot. Presumably this IR circuit board senses the horizon to judge attitude in each axis- which is why it mounted outside the fuse in such an awkward position.

Regardless, its just interesting, its gonna be ripped out and the holes patched up
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Old Oct 19, 2015, 06:04 PM
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Quote:
Originally Posted by lFritZl View Post
.... My first thought, before i had bought the plane was that something like a higher kv 480 on 2s would be sufficient. While that might have been a bit under powered it shouldn't need more than 300W should it?

The glider drive 960 comes in at 309 W on 3s (see pic below). Bit heavier than i hoped, but its a proven setup (by 2400RDR) at least.
If I recall correctly, the OLY needed quite a bit of weight in the nose to balance it as a pure glider. The fact that my OLY balanced perfectly with the motor I chose serendipitously tells me that it must approximate the weight you would have added to the pure glider. It follows, I think, that if that is the case, the only extra weight I added was the lipo under the wing, which isn't much.

LOL- I think we may all be over-thinking this a bit. I'm sure it'll fly just fine with whatever motor you decide to use.

Does the glider balance on the spar now? If so, how much weight is in the nose? If not, how much weight do you need to add, and what is the total to make it balance as a pure glider (no motor)? How does that compare to the weight of the motors you are considering? There may already be lead in the nose of that OLY that you aren't aware of.
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Old Oct 19, 2015, 06:11 PM
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One other thing- it looks like you have spoilers already built into the wing on that plane. If so, you probably won't need to windmill the prop to land. I built spoilers into the wing on my OLY, and it drops nearly like a stone when they are deployed. In other words, they work very well.
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Old Oct 20, 2015, 12:09 PM
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Quote:
Originally Posted by 2400RDR View Post
If I recall correctly, the OLY needed quite a bit of weight in the nose to balance it as a pure glider. The fact that my OLY balanced perfectly with the motor I chose serendipitously tells me that it must approximate the weight you would have added to the pure glider. It follows, I think, that if that is the case, the only extra weight I added was the lipo under the wing, which isn't much.

LOL- I think we may all be over-thinking this a bit. I'm sure it'll fly just fine with whatever motor you decide to use.

Does the glider balance on the spar now? If so, how much weight is in the nose? If not, how much weight do you need to add, and what is the total to make it balance as a pure glider (no motor)? How does that compare to the weight of the motors you are considering? There may already be lead in the nose of that OLY that you aren't aware of.

Yea, ok, that sounds like a good way to go about it. Ive pretty much settled on that glider drive 960 setup above. If this plane balances with it and no extra weight, as yours did, its a sure thing ill go with it. I'll get some lead out and load it up, see what happens.

And yes its got some lead stuck on to the inside of the battery latch, but I'm sure it must of still had more to balance it as an un powered.

Quote:
Originally Posted by 2400RDR View Post
One other thing- it looks like you have spoilers already built into the wing on that plane. If so, you probably won't need to windmill the prop to land. I built spoilers into the wing on my OLY, and it drops nearly like a stone when they are deployed. In other words, they work very well.
It does have spoilers already, I'm pretty keen to see how well they work. Is there any pitch change when deployed? Also whats a good max travel angle to set them to?
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Old Oct 20, 2015, 01:31 PM
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It does have spoilers already, I'm pretty keen to see how well they work. Is there any pitch change when deployed? Also whats a good max travel angle to set them to?
Your spoilers appear to be the type that telescope out of the wing and probably work pretty well. You'll probably need some up elevator to control the sink rate, but theres no way to know how much until you give it a whirl.

I'm not sure, but I think when those deploy, there are fully up, but never having used that type, I can't give much advice.
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Old Oct 20, 2015, 01:45 PM
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Those spoiler will likley swatt the Oly out of the sky. Go easy on the deployment and do so at altitude. Be ready to compensate with elevator. Each plane reacts slightly different to spoilers.

Unlike flaps, the plane will continue to fly if you quit the spoilers. Flaps can drag your plane under stall speed and leave you in a lurch if you retract them at the wrong time.
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