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Old Jul 14, 2014, 09:16 AM
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Rusty Mustard's Avatar
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I second the FlyTrap as an RM build, it's a great shape with a pile of advantages. Or an even higher aspect wing. Weasel and Alula shapes work well, but anything with sweep and taper really seems to shine as it takes full advantage of several features of the RM1.
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Old Jul 14, 2014, 05:56 PM
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ak68's Avatar
Nederland, ZH
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Thanks for pointing in the right direction and for sharing test experiences.
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Old Jul 17, 2014, 06:08 AM
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Ashford. Kent. England
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note I have just run a side by side comparison with RM1 to KFm11
conditions were poor very low lift

the RM1 at 4ozsqft 30" span 8oz AUW
and the KF at 4.9ozsqft 1.6M span at 13.4oz AUW

the KF gained height significantly better.. but it was a higher aspect ratio wing.. just how much difference that makes I have no clue
...
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Old Jul 17, 2014, 12:53 PM
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Dave, what are the cubic loading figures for each?
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Old Jul 20, 2014, 04:46 AM
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cubic loadings???? wouldn't know where to start for that...

wing loadings are as above
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Old Jul 20, 2014, 09:50 AM
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Dave, just bring your area and AUW over here and get your cubic loading:

http://www.ef-uk.net/data/wcl.htm
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Old Jul 23, 2014, 02:34 AM
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cubic loadings ....
I still don't understand the relevance or the why of these numbers....despite reading the linked article on the calculator page...sorry...
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Old Jul 23, 2014, 11:45 AM
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United States, AZ, Prescott
Joined Oct 2013
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Great looking wings guys. I want to get into DLG and want to build an Alula clone out of dollar tree foamboard:
What size wingspan should I go with?
Building it flat looks easier; do you need dihedral for DLG?
May I shamelessly copy your designs if I promise to only use these plans for good?
I really like Steve O's one piece body/nose.
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Old Jul 23, 2014, 12:11 PM
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Joined Dec 2012
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Parajared - build it flat with DTF paper peeled off just like Dave Reap's plans back at the beginning of the thread. Full size works great. I upped it to 48" wing span and added that nose job for durability. Still flying it although it needs replacing. DTF gets mushy after many crunchy landings. I slope mine rather than SAL (side arm launch) on flat land.

Feel free to use the nose mod I did. These are not true Alulas per se so the proprietary airfoil used by that plane is not infracted upon.

36-39" is about right for wing span. The build is fairly straightforward. Get the CG right on and have fun.

Laminating the airframe makes for a MUCH more durable bird. Film or tape works.

On DLGs - I have 5 and yes they need dihedral. 5.5 to 6 or so degrees each wing. Otherwise you'll have an unstable VERY hard to fly glider. Best route IMO is to buy good condition USED, already built and a mentor with it. The learning curve is not terribly steep but a few critical steps between success and CRUNCH!

I slope my DLGs, too, they will soar when even the Alula is grounded.

HTH and good luck.

PS- two videos of my first regular sized and my Jumbo-lula

Alula Clone Sloping (4 min 52 sec)


Jumbo Alula clone cruising the slopes @ POTM (3 min 11 sec)
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Last edited by Steve 0; Jul 23, 2014 at 12:20 PM.
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Old Jul 23, 2014, 12:23 PM
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Quote:
Originally Posted by davereap View Post
cubic loadings ....
I still don't understand the relevance or the why of these numbers....despite reading the linked article on the calculator page...sorry...
Dave, it simply gives a rating to compare one plane against another, and to predict performance when scaling a model. Think of the numbers as a rating scale for ease of flight, and not just ease skillwise, but ease as far as the plane is concerned.

Stuff with a cubic loading of under 2 will respond similarly, regardless if the span is 20" or 20 feet. They'll both be floaters at the weight that produces that cubic number, though the 20 foot spaan will not be as agile, they'll fly in 'under 2' wind and lift conditions.

The 'under 2' wind would be what i consider light, under 10mph and average of 7mph. Anything with a cubic loading of under 2 will be happy in this kind of wind, and knowing the cubic, you can get a better idea what will fly in what kind of conditions. Bring the cubic range up to 4 and you'll need a medium and even borderline of heavy wind to keep a 4.0 in the air. Above 4 and you're leadsledding, or flying power. Fast sport planes, racers, warbirds, and some jets have a cubic into the 20's and are bricks power off.

Basically it eliminates the effect of scale and aerodynamic factors and produces a numerical value that can be used to compare aircraft of wildly different dimensions and square loading.
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Old Jul 23, 2014, 08:36 PM
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Ashford. Kent. England
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Ive been reading up and get what you mean, and the idea behind it... .. that cubic system I had never heard of before...


plans... any of my plans are there to use, abuse and improve on , do whatever you want....

For Improvements .. don't forget to post pics and info...
for dislikes do the same..
pinch any ideas that work and put them in your models...
have fun.....
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Old Jul 24, 2014, 10:02 AM
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United States, AZ, Prescott
Joined Oct 2013
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Looks like fun, I'll round up some foamboard and some arrow shafts get to work.
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Old Oct 26, 2014, 07:39 PM
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Nederland, ZH
Joined Dec 2011
667 Posts
The magnificent sunset (timelapse @ 0:50 included) was a good compensation for the lack of height, lift and wind.

Some flatland A-clone attempts to break the silence:
alulah08 (7 min 41 sec)
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