midge píše:Few people here in Czech republic would like to try it. I fly 3 years with Wasabi, but your models are little different due to less weight, you know, what I mean.
Yes, I know what you mean - I have flown the Wasabi for about 5 years, I had the first one that came to the USA, and I wrote the English build instructions for it. It's a great plane, but completely different from these ultralight Le Fish in every way!
The original Le Fish was much heavier, almost 1100g
It is still a successful design at that weight, but, it requires more wind to fly. Now with the 470g version of Le Fish, we can fly in as little wind as a Weasel-Evo, but still be fully aerobatic. That is the big advantage to these light planes: when before it was impossible to fly VTPR and aerobatics because of not enough wind, that is no longer a problem. So: we can improve more quickly, because we can fly 3-axis aerobatics at all time, using the 470g Le Fish when conditions are soft, or the Voltij / Wasabi / etc when conditions are strong.
And of course these light planes, because they have so little mass and fly so slowly, are very durable. Which means we can fly very close to the ground with little danger of damage in a crash. It is more like a skateboard or snowboard: you do not worry about damage because it is very hard to hurt the plane, which in turn lets you try to fly closer, or attempt new tricks, and therefore progress your flying faster.
Me and my friend Pepin (he is also here) want to try two alternatives. First something with wing from styrodur (harder and fragile then EPP) with cover. Of course it will be heavier then Your ultralightweight Le Fish. I know, that community about SlopeAerobatics. com use modified SB96V-SB96VS profile. Do You know, how it is modified, or can You send us this profiles?
For the second, we also would like to try something just like Yours ultralight LeFish.
Which profile do You use on your front EPP wing section ? I understand, that ailerons are from Depron.
Do You use removable elevator ?
Is Your wing removable from fuselage? If Your wing is from one piece and is removable, how it is connected to fuselage ?
Is angle adjustment Wing x elevator 0 grad ?
These are currently main question, if You could give us answers and maybe send few photos. Thank You very much.
Unfortunately I do not have the modified SB96V / SB96VS profiles; that is something offered only in the kit from Leading Edge Gliders. However, I do not think there is a significant advantage, for these light planes, in using that airfoil versus the standard SB96V and SB96VS airfoils for ultralight VTPR flying. The SB96V and SB96VS were designed in France for exactly this kind of flying, and are absolutely reliable choices, and I use the unmodified airfoils in my own projects with no complaints.
The ailerons, elevator and rudder are all made from 5mm or 6mm Depron and covered in a very lightweight, iron-on 1.7mil laminating film: http://www.laminatorwarehouse.com/index ... _id=400014
You could also use a traditional iron-on film like Oracover or Solite, the important thing is that it is as light as possible.
The wing is one piece and is not removable. I own a fairly small car by US standards and it is no problem to fit the Le Fish inside. A 2 piece wing is possible and I plan to build my next plane that way.
The wing uses a single carbon fiber ribbon spar inserted vertically about 50mm back from the leading edge, a second ribbon spar (the same size) glued to the subtrailing edge of the wing. These are the spars I use: http://www.canuckengineering.com/new/co ... lat-ribbon
We use a 102mm wingtip (not including the ailerons) and a 177mm root. The ailerons can be made straight 50mm from tip to root.
The elevator is not removable, because I wanted to save the most weight possible and keep it very simple. But if you use a square joiner similar to the Kulbutin you could certainly achieve this, with a small weight penalty. Please note that the elevator is capable of significant rotation, just like the Madslide and Kulbutin. That is what makes the flips possible - as seen in the very beginning of the video I posted.
Speaking of weight, at 470g it is a lot of fun to fly these planes, but unless you need to fly in very light conditions, it is OK to build a bit heavier. Dawson Henderson of Arizona has one that is about 600g and seems to enjoy it quite a bit. Anything 700g or less should be a lot of fun and quite versatile in light lift conditions.
I hope this helps. There will be a proper free downloadable plan for the plane very soon, and I will post it on my website. It will include DWG / DXF files that can be used for CNC cutting, as well as a A0 plan for printing out and taping together.
The entire design is released under the Creative Commons license allowing commercial use of the design without payment to me, so long as I am given credit as the designer. Also, if you make changes to the plan as part of a commercial offering, you are required to provide the details of the changes along with the glider. This is the "open source" philosophy applied to aircraft design and my intention is to help promote the availability of better and better gliders in the future. And of course for personal use all I ask is that you tell me about your projects so I can put them on my website and take the pleasure of seeing my designs flying around the world!
As you can see, I am simply a maniac for aerobatics gliders and my only goal is to help encourage this kind of flying worldwide!
Best regards,
Steve
