|Jul 14, 2014, 08:16 AM|
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.
|Jul 17, 2014, 05:08 AM|
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
|Jul 23, 2014, 01:34 AM|
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...
|Jul 23, 2014, 10:45 AM|
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.
|Jul 23, 2014, 11:11 AM|
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
|Jul 23, 2014, 11:23 AM|
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.
|Jul 23, 2014, 07:36 PM|
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...
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