SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
This thread is privately moderated by aeajr, who may elect to delete unwanted replies.
Old Jan 28, 2008, 02:08 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
864 Posts
The Spirit ARF 2M has a nasty decalage. Get small pieces of 1/4 and 1/8 ply and shim the trailing edge of the wing. Mine uses the 1/4 shim and stop the tendency to ballooning. Now she flies very well at some decent speed range.

Saludos.
Ricardo RW is offline Find More Posts by Ricardo RW
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 29, 2008, 08:28 PM
Registered User
Eastern North Carolina
Joined Oct 2004
96 Posts
HI-start came in yesterday. According to the plans the CG is at the spar. I have rebalanced and will give it a try this weekend and see if I can work in some of your suggestions.

Ill keep you posted. Thanks for your interest and help

Randy
PLRDad is offline Find More Posts by PLRDad
Reply With Quote
Old Jan 30, 2008, 02:42 PM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
Quote:
Originally Posted by Ricardo RW
The Spirit ARF 2M has a nasty decalage. Get small pieces of 1/4 and 1/8 ply and shim the trailing edge of the wing. Mine uses the 1/4 shim and stop the tendency to ballooning. Now she flies very well at some decent speed range.

Saludos.
Ricardo,

I have 2 new GP Spirit 2m ARF's and am readying both. I've heard of this decalage issue with this design. Could you not also change the angle of the stab? It seems it would be safer and more rigid to leave the wing fully seated in the saddle or build the saddle up uniformly other than just shimming the TE. Is this decalage issue strictly geometric?

Don
dwells is offline Find More Posts by dwells
Reply With Quote
Old Jan 30, 2008, 03:00 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,476 Posts
If the h-stab glues on, once you glue it you can't change it. If you are going to change it you have to do it before you glue it.
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Jan 30, 2008, 03:57 PM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
Hi aeajr,

Mine are just bolted on at this point. I know by reading your posts that you have a lot experience with the Spirit. I'm a newbie to all this and want to make sure everything is good to go before the first flights. I have set CG at 3.5" from LE, Gordy Stahl suggests 40% of root to start (which is 3.6" on the Spirit) no matter what the plan says. I thought I would start .1" ahead of that. Sorry, back to decalage, has this been a factor for you with the Spirit?

Don
dwells is offline Find More Posts by dwells
Reply With Quote
Old Jan 30, 2008, 04:02 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,476 Posts
I always start at the plan setting. Then over time, I move it back as I get to know the plane.
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Jan 30, 2008, 04:43 PM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
Have you modified your Spirits for the decalage correction?
dwells is offline Find More Posts by dwells
Reply With Quote
Old Jan 30, 2008, 07:23 PM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
864 Posts
Quote:
Originally Posted by dwells
Could you not also change the angle of the stab?
Yes, you can. The point here is 'how much.' To find out, I suggest you to dial in small amounts under the trailing edge of the wing until you get it (stop ballooning). Then, apply that shim to the *leading edge* of the stab.

With this you'll get *another* plane, that flies very well.

Try it! You'll not be disappointed.

Saludos
Ricardo RW is offline Find More Posts by Ricardo RW
Reply With Quote
Old Jan 30, 2008, 07:57 PM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
Thanks Ricardo...great idea!
dwells is offline Find More Posts by dwells
Reply With Quote
Old Jan 30, 2008, 08:25 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,476 Posts
Quote:
Originally Posted by dwells
Have you modified your Spirits for the decalage correction?
I had the Spirit Select. The stab and fin are held on by a bolt. I removed them and trimmed down the back of the bed where the stab sits. Now if flies much better.

You can also shim the back of the wing, as described earlier.
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Jan 30, 2008, 09:05 PM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
It's interesting to me that this design flaw has not been corrected over the years. it's very apparent to me now just by eyeballing the wing saddle compared to the stab mount...what the heck. Should I fly the plane first or go ahead and trim it up a little before hand?
dwells is offline Find More Posts by dwells
Reply With Quote
Old Jan 30, 2008, 09:47 PM
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
24,476 Posts
If you have a wing incidence gague, you can measure it first. I did not have one at the time.

I can't say if yours needs correcting or not. There is probably some in there by design but the one have had too much.

If you can secure it temporarily some way and fly it and see, that would be best. Or figure out how you would fix it before you assemble it that would be excellent.

On page 27 of the kit manual it indicates that the wing and stab should be parallel to each other. So take a look.
http://manuals.hobbico.com/gpm/gpma0530-manual.pdf
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Jan 31, 2008, 07:27 AM
.: Looking for Thermals :.
Ricardo RW's Avatar
Chile, Quinta Región de Valparaíso, Los Andes
Joined Jun 2002
864 Posts
Hey dwells,

Don't believe us... do some trials

Fly the plane as stock, note how she reacts to different speeds, then add some shims, 1/8 or 1/16 increments and try to find differences.

Stay with the most comfortable setup, that suits better your flying style, then glue everything and go enjoy the Spirit.
Ricardo RW is offline Find More Posts by Ricardo RW
Reply With Quote
Old Jan 31, 2008, 10:40 AM
≡LSF8067≡
dwells's Avatar
Bedford, TX
Joined Oct 2007
2,845 Posts
Thanks guys,

Great advise/ideas. I appreciate the feedback...

Don
dwells is offline Find More Posts by dwells
Reply With Quote
Old Feb 02, 2008, 09:24 PM
Registered User
Eastern North Carolina
Joined Oct 2004
96 Posts
Wow! The altitude that I was able to accomplish with the real hi-start was amazing. The air up there is different. I managed to achieve several flights over 5 min and one over 7 min. My neck was getting tired. I can see the usefullness of a lounge chair.

Aeajr, I tried your suggestion with the dime taped to the tail a couple of times. It did not seem to help; at least my times dropped. I am not saying I have given up on that but that was what happened today. I did catch one small thermal but did not stay with it very well.

Oh, well all and all it was a great day. I was out for 3 hours with a couple of new flyers and they were really impressed with the launch and flight of my Spirit.

Randy
PLRDad is offline Find More Posts by PLRDad
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
easy way to use hi start jtraxler Sailplane Talk 16 Dec 12, 2007 10:50 PM
Learning to use AutoCAD 2002 OCModels Power Systems 4 Mar 07, 2002 11:55 AM
Need a source for hi start tubing Jar'sbuddy Electric Sailplanes 3 Feb 01, 2002 12:11 PM
NIB Dynaflite Hi-Start (standard) JCastle Aircraft - Electric - Airplanes (FS/W) 0 Dec 27, 2001 10:15 PM
How can I make a hi-start?...I've got the materials kiwip Electric Sailplanes 6 Jul 02, 2001 10:14 AM