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| hjlittman, Comment for image # 29028 | 13 Apr 13 18:01 |
| It's not as light as it looks. This particular one weighs 15 grams. with rubber, ready to fly, but has almost 90 square inches of wing area. The latest version weighs 13 grams and I have an even lighter one that I did just to see how light I could make it. Well, that didn't work out too well. The super light one was made of "contest grade" 1/20" stock. The uncovered frames weighed 4 grams. I didn't get an all up weight for it because as I was carrying it out the garage a gust of wind came up and suddenly I was holding shreds of tissue with bits of balsa attached. The lesson? 1. You can make them too light, and 2. Indoor models should not travel outdoors when not in a box. |
| peregrin, Comment for image # 29028 | 13 Apr 13 00:49 |
| so nice. it just barely exists! how much does something like this end up weighing? |
| hjlittman, Image # 29028 | 12 Apr 13 19:50 |
Later F7U Improvements still coming |
| hjlittman, Comment for image # 28829 | 14 Mar 13 16:20 |
| Unfortunately, a bit too light. The model,except for the wing spars, is made of "contest grade" wood (4-6 pound/cu ft). While it did improve the climb rate over the original version it turned out to be so fragile that I could not make adjustments without breaking something. It also could not take contact with walls and fixtures with no damage like the original. The definitive version has a few changes to the structure and all the strip stock is 8-10 pound wood like the wing spars. I'm working on a prop design that will give as much thrust but be lighter than the Peck prop I have been using. |
| poppy, Comment for image # 28829 | 14 Mar 13 09:02 |
| It looks light as a feather! |
| hjlittman, Image # 28829 | 13 Mar 13 22:40 |
Improved version of F7U. Reflexed airoil, larger elevons, dihedral in outer panels. Still not ready for prime time. Further redesign in the works. |
| peregrin, Comment for image # 28780 | 06 Mar 13 21:00 |
| nice scale look from this angle. I'm looking forward to seeing the flight vids. |
| hjlittman, Comment for image # 28780 | 06 Mar 13 16:41 |
| Finally, someone made a crack calling it a flying wing. I thought, "Why Not?", and added trim tabs to the trailing edge of the wing and proceeded to forget the canard and trim it as a delta. Voila! It Flies! It is a bit heavy and needs a 30 inch loop of 3/32" rubber to fly, but with a hollow box or rolled tube motor stick I think I can get 10 grams off of it which should let it fly on a loop of 1/8". Much to the surprise of those who said that I would need a larger gym to fly it the turning circle is actually tighter than the F7U. I'll try to get movies this Friday at Luther. |
| hjlittman, Image # 28780 | 06 Mar 13 16:29 |
This is what the Viggen looks like finished. Spent a fustrating morning at Stonehurst trying to trim it to fly. It's a lot stronger than it looks. |
| hjlittman, Image # 28768 | 03 Mar 13 15:09 |
My wife looked at it and said it looks like a cartoon. Since a no-cal IS a cartoon of an airplane I suppose that was a complement. |
| hjlittman, Image # 28767 | 03 Mar 13 15:07 |
Since the root chord of the wing is over 13 inches long I had to use a 2 foot square piece of plywood to pin down the wing while shrinking. |
| hjlittman, Image # 28766 | 03 Mar 13 15:05 |
The size of the Viggen caused a few problems. Pinning it down to shrink the tissue I had to use the plywood plank I normally use for wings. |
| hjlittman, Comment for image # 28746 | 28 Feb 13 15:46 |
| The Viggen is huge. With a 16 inch wingspan it's 28 inches long. It would be too delicate to put into kit since only an experienced indoor builder could build and handle it. It's a real "balloon" weighing only a couple grams more than the Cutlass but with 20 square inches more lifting surface. The Cutlass is a classic no-cal covered on one side only. The elevons were glued at the ends with a flexible glue and only fixed in place with C/A after flight testing had determined the optimum position. I am redesigning it with a reflexed airfoil so that "anyone" will be able to get it properly trimmed. |
| peregrin, Comment for image # 28746 | 28 Feb 13 15:23 |
| I feel like if I look at it too hard I'll break it! I was wondering about the Cutlass: are the bottom of the wings covered or left open? and were the elevons hinged and adjustable? |
| hjlittman, Image # 28746 | 27 Feb 13 18:24 |
This was my back up model for the NoCal contest, a Saab Viggen. I didn't get it finished and the Cutlass flew OK. I finished 2nd by 0.8 seconds. http://www.youtube.com/watch?v=DQn4v3mROw8 Next week I will fly the Viggen. |
| hjlittman, Comment for image # 28683 | 23 Feb 13 01:15 |
| Try this link as a good place to start http://fwcg.3dzone.dk/ The Cutlass is more stable than the usual flying wing because of the large fins and the fact that it is almost a delta. |
| FLYBOYZ, Comment for image # 28683 | 22 Feb 13 22:27 |
| Very cool hjlittman how did you come up with the CG on your
cutlass being a flying wing?Ive been very interested in flying wings |
| peregrin, Comment for image # 28683 | 22 Feb 13 18:17 |
| well I like it. I found this site while trying to figure out how to adapt some ff models to micro-RC and am finding myself being won over to free flight. |
| hjlittman, Comment for image # 28683 | 22 Feb 13 18:04 |
| No, this is my design I used the Guillow's listing to get the F7U designation because I just didn't get around to asking James to add it to the list. The Guillow's version was an all balsa glider with about a 10" wing span. |
| peregrin, Comment for image # 28683 | 22 Feb 13 17:56 |
| really cool! I was hoping it was in the Guillows catalog somewhere that I missed! |
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