spiral_72

I have a Spirit 2M sailplane from my youth. The radio system is pretty old but the servos still work. I bought a glow powered trainer and computer Airtronics radio system for the trainer a couple months ago trying to relight the old interest.

I'd like to buy a Rx for my Spirit. I have the option of a flight pack with the Rx I've chosen. The plane has two standard Futaba servos in it now (Elevator & Rudder).

Should I go with micro servos? Will they handle the load? Will te weight savings make any difference?

I appreciate the opinions. I don't have anyone I can really ask except here.

rscarawa

The load that the control surfaces put on the servos in a Spirit is not very significant. I think something with 30+ oz of torque will be all you need. I use Hitec HS81 in my Spirit with good results.

As far as weight savings making a difference, I think not much. I have been flying my first Spirit with electric power for about a year now and like the way it flys better with the extra weight. I get much better wind penetration than before and glide speed has only increased a slight bit. I also had to reduce the amount of full up throw a little bit since it cannot cut as tight a circle as it use to.

If you use lighter servos, will you have to add lead to balance the plane? If so, then do not change them out.

Light weight is not everything in soaring. I think it is over emphasized.

knowhereman

Spiral,

I am currently flying mine with standard size s3003 and a mini s3001 for the spoilers and it will gain height from a mouses fart. Keep standard and get her flying.

Knowhereman

spiral_72

Well, good. There hasn't been an overwhelming reaction to my poll.... but it looks like I'll stick with what I have.

I'd like to have better luck with thermalling this time. Where I fly is pretty much open field and trees. There are two roads which is the only place I have been able to find a thermal as a kid. The Spirit is about 12 years old. She'll be glad to have the dust blown off I'm sure.

Thanks for the input!

rscarawa

Is your CG at the rearward most limits? That really helps sensing thermals on this ship.


Scot

spiral_72

Ah, I just pulled it from it's resting place the other day. It'll have to be setup all over again. I'll make sure I follow that instruction though as soon as the Rx comes in.

I wondered about that... something I noticed with my trainer. Obviously not thermals, but that the plane was very sensitive the closer I got to perfectly balanced on the CG. Then I added a touch of nose weight on that model. The glider will be different I'm sure, but I'm going to start from there and make changes.

Trying to Google a how-to on thermalling now. Not much luck yet.

papermache

My Feedback: (35)

Spiral,

If you install smaller servos, you'll add the weight difference in nose weight to balance it. I'd rather have my weight doing some good. So stay with the standard size servos.

papermache

bkdavy

My Feedback: (1)

I made the mistake of setting my Spirit 2M up at the forward range of the CG in the instructions. That took at LOT of non-working nose weight. After some more research and flying experience. I stripped out all the nose weight. The CG is now actually behind the recommended range, and the plane flys SO much better. I use standard servos, and have no complaints about the ability to locate and ride thermals. All my recent attempts have been terminated by transmitter battery (which has been replaced as of today).

Brad

rscarawa

Try this:
http://www.charlesriverrc.org/articl...GMarkDrela.htm

Bud Faulkner

My Feedback: (1)

I just got a DVD yesterday in the mail from soaring USA called Performance tuning. In it he covers the spirit 2M and how to properly set it up for better performance along with a lot of other hints for setting up your sailplane. Not just the spirit.....that's just one example. He stated the stock setup doesn't fly that well and also suggests moving the cg rearward. Flight pictures included of the spirit. Very informative and worth the $25.00 Bob at soaring USA has been very helpful in getting me back into sailplanes after a very long layoff because when I was flying them in the 60's everything was tow and now I'm going electric which I know nothing about.

Bud

pilotpete2

The standard servos will work fine and last a long time.
Now if you didn't have those servos for the plane, then I would recommend mini servos such as the hs-81, that's what I use in 2M thermal ships. I would not recommend true micro size servos such as hs-55 for a 2M sailplane.
Good luck,
Pete

RRW_SOAR

Better move the servos forward.

rscarawa

If the servos do not weigh much to begin with, then moving the servos forward to help with CG will have less impact. It is one thing to move two servos weighing 1.5 oz around to alter the cg than it is to move two servos weighing .5oz.

aeajr

My Feedback: (2)

I have a Spirit 2M and I like it a lot. I suggest you move the servos forward if you can. See the photo attached.

BTW, Hitec HS-81s can handle the Spirit just fine. And I know of people using Hitec HS-55s. Other options would be Hitec HS-85s or GWS mini servos. All would fit just fine and have plenty of power. As stated earlier, the load on the surfaces is not much. I would say any servo over 22 inch/ounces should be fine.

But shift it all forward to get the plane lighter. By doing that I removed 3 ounces of lead from the nose and it made a huge difference in how the plane flies.

Note that those are Hobbico standard servos in the photo. If I did it again I would use the HS-81s.

spiral_72

Great! A wealth of info. That's what I wanted...... I noted all the ideas. I'll work it all out soon as my Rx comes in. A great hobby shop just opened about 8 miles from the house. He's got a pretty good selection of servos (and other stuff).


Thanks for the info..... been a big help.

I haven't found what I'm looking for yet...... an instructional how to find/ride thermals. Any link?
I thought surely it'd be on RCU, but maybe I'm not searching for the right keywords.

Bud Faulkner

My Feedback: (1)

Try this. There's a video preview on this link also.


http://www.soaringusa.com/products/p...ategory_id=382

Bud

aeajr

My Feedback: (2)

What servos did you install?

Are you still looking for tips on thermals? Search on the Glider Pilot's Handbook.

daja

Spiral_72
I am not flying a Spirit, but I have done some weight shifting in my Drifter II (2 meter) recently. I live in the north west end of the country and we don’t have a lot of real warm days. I wanted to make the plane more responsive to thermals. This sailplane is a bit of a floater. I originally set up the plane with a standard Futaba receiver under the front of the wing and S3004 servos in line. The plane came in at 27 plus ounces. After swapping the reciever for a berg 4 channel and installing some Hi-tec 85bb servos the plane is now at 24 plus ounces.[X(] It made a huge difference flying it. The biggest change is when you are thermalling low and are about to give up and start a landing pattern. With the less weight you can thermal much lower and feel totally comfortable to continue looking for more lift. You can always add ballast for windy days. My vote is, you will enjoy flying the lighter sailplane.[8D]
daja

spiral_72

Sorry, I didn't see your reply....

I ended up installing some standard sized servos. I jammed everything as far forward as it would go and made new pushrods. I had some micro HS-81's I could have installed, but as another poster pointed out, lighter servos would unload the nose and I'd just have to add nose weight to compensate.

I was able to take out some nose weight and fly it. Although something has changed since I was a kid. It's not the same.

Since then I've rebuilt the canopy and some other things and lost another 3oz. I'm toying with the CG and some other things now trying to get her to fly again. I've got some recent posts on RCU trying to iron out my difficulties. It'd help if I knew someone in the area with glider experience....... I'm following one lead now, a guy nemed "Bo". Hopefully he can tell me what's wrong.


The Glider Pilot's Handbook, I'll search that in a few minutes.... Thank you!