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AIRTRONICS CUMIC PLUS ADVICE

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AIRTRONICS CUMIC PLUS ADVICE

Old 04-25-2007, 07:14 AM
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knowhereman
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Default AIRTRONICS CUMIC PLUS ADVICE

I have just bought an Airtronics Cumic Plus RES Kit.

Do any of the more "Experienced" among us remember it and recommend any modifications so I dont waste this kit and get it right the first time.

Old 04-25-2007, 08:24 AM
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Default RE: AIRTRONICS CUMIC PLUS ADVICE

I remember it, basically a Saggitta with a glass fuse, and I think a little longer wing. It was a little late to the party to be competitive in Unlimited class which had moved on to Windsongs and Magics, but a good airplane. The one my fiend flew had extended wings and wallowed some, so if there's an option to build two lengths go for the shorter wing.
Old 04-26-2007, 05:40 PM
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Default RE: AIRTRONICS CUMIC PLUS ADVICE

I agree with soarrich; go with the standard (100") wing. Also, if I was building one, I would probably install a carbon fiber wing rod and tube; the temptation to install flaps would be strong as well. After that, just the usual - build as light as possible and take extra time to make sure everything is straight.
Old 04-26-2007, 06:16 PM
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Default RE: AIRTRONICS CUMIC PLUS ADVICE

Thank you for both of your inputs. I am building this one until Aerosphere release the Sagitta XC later this year.

I havent used Carbon hardware before, havent had a plane that needed it!! I think flaps will go in for sure.
I looked at the specs for the Cumic and the Cumic plus and they have the same Fuselage length 49 inches and 17 inches difference in wingspan. Seems a little strange, if it was a built up fuse then maybe I could extend it.

What are your thoughts on the counter balanced Rudder? I have seen on here people saying lose it and go for conventional.
Old 04-26-2007, 11:42 PM
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Default RE: AIRTRONICS CUMIC PLUS ADVICE


ORIGINAL: knowhereman

I looked at the specs for the Cumic and the Cumic plus and they have the same Fuselage length 49 inches and 17 inches difference in wingspan. Seems a little strange, if it was a built up fuse then maybe I could extend it.
It has more to do with the wing chord than the wing span.



ORIGINAL: knowhereman

What are your thoughts on the counter balanced Rudder? I have seen on here people saying lose it and go for conventional.
lose it and go for conventional It really improves the handling, the launch is much straighter without the counterbalance on all the Airtronics sailplanes, it was a bad idea.
Old 04-27-2007, 01:48 PM
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Default RE: AIRTRONICS CUMIC PLUS ADVICE

I bought 2 new Cumics about 12-15 years ago at a hobby shop close down sale 2 for the price of one. I built one kit and flew if for many years and sold it. Still have a NIB 100 inch Cumic. The fuse is the same for 100 or open class. I saw a Plus one time and it was the same as a Cumic except it had 6 more bays in the center section of the wing, the tips where the same. My plans show both wing but the wood is different in the kit from a Plus. I think the plain Cumic was a better over all flyer, could handle the midwestern wind better that a Plus. The Plus I saw flew like my Mirage or just a tad faster than a Paragon. For their time they were pretty good fliers but had a differrent airfoil than the Saggitta which was thinner and faster flight was possible.
If I were to build one for todays winches you would need some C/F on the spars or be prepared to tap-pedal it up. Winches are a lot different than they were 20 years or so ago when this plane was designed!!!!!!!!!!

Good Luck
Bob
Old 05-02-2007, 09:11 PM
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John Walter
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Default RE: AIRTRONICS CUMIC PLUS ADVICE

If you add carbon to the spars, be sure to bond well with epoxy then wrap the spar, especially the joiner box and poly breaks, with Kevlar tow to take the bursting load. Take a look at:

http://www.rcgroups.com/forums/showthread.php?t=587629

Full disclosure, Littleflyer is my son

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