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I would like to know if there are any designs for either side arm launched or discus launched free flight gliders. I am new to this form of free flight, but want to pursue gliders actively. Thanks.
Hi Phil
Welcome to a facinating branch of our sport. As you have stated, you are new to gliders and I would therefore recommend the purchasing of a kit (or kits) for some of the “cottage industry” suppliers who specialise in HLG’s to get a feel for timber selection and construction techniques now being employed, yes it has advanced quite a bit for the old traditional all balsa days.As for discus launched models, there are several experimenters in England and you will find a plan and some details published in the 38th Annual Free Flight Symposium available from the NFFS, not mainstream at the moment but who knows! 😀
@Phil Puzick wrote:
I would like to know if there are any designs for either side arm launched or discus launched free flight gliders. I am new to this form of free flight, but want to pursue gliders actively. Thanks.
Some flyers from both sides of the Atlantic are working on DLG at this forum.
http://www.smallflyingarts.com/cgi-bin/yabb/YaBB.pl?board=Gliders;action=display;num=1117471222
Thanks for the replies. I was almost sure it had reached this point of development. I have followed the R/C versions and even plan on building one. Back in the early 80s I flew a Flinger by Larry Jolly and had a lot of fun, but not much success in the way of duration. Disappointing at the time because I lived in TX – home of some monster boomers. I have a Sweepette 19 and a Straight Up catapult that are trimmed out moderately well, I guess. Did manage to get the Sweepette into a thermal at a small park. Broke a minute before hitting a tree. I may try it with some additional reinforcement and a discus attempt.
Thanks again for the help and encouragement. I know this 54 yr. old arm won’t take the old style for much longer.How hard is DLG launching on the lower back?
bill L
I built a Discus Glider and tried it out at the Muncie Nats. It still is a work in progress. I am going to modify mine, and see how it flies then. As to the effort on the lower back, I don’t think there is any strain on it. No more than swinging a golf club. You don’t have to put a lot of effort into the launch. Len Surtees is selling kits, and I think it is a good place to start you experimentation. A nice kit that builds into a good airplane.
Well, you guys have convinced me….I looked at the website above and did very little research and have one 75% done. It is big! 36″ wing, 6 panels, V stab and bottom fin. Used some carbon to reinforce the dihedral on the launch side (left). Maybe will put a peg in it for throwing. I hope that the discus launch will allow me to throw again, as I screwed up my shoulder a long time ago throwing.
Now the interesting thing. Just think if we have 4 or 5 of these guys in the pig pen!! May need to make the old pen bigger….Swinging one of these things around takes alotta room. I am looking forward to playing with this.
I have modified my Sting Discus glider as per the mods discussed in the NFFS Digest a few months ago. Took out an extra incidence block, cut the wing in half and added approx 5 degrees dihedral to the center panel. Removed the tail and converted it to a “V” tail with a sub fin. Too windy by far to test at the moment, but will try it out next week and see what develops.
Tried out the Sting and it did very well considering the poor conditions. Hint to people making a big discus glider. Make it very strong and tied together. They have a lot of momentum and tend to come apart in the usual noselow, cartwheeling spiral- in crash. The launch is starting to look good though. More experimentation is in order.
“the usual noselow, cartwheeling spiral- in crash”
Does this mean that it’s difficult to make the transition to glide when the fin is large enough to keep it directional during the launch?No, actually it made a number of pretty good transitions. Some were very good indeed. No bad ones at all. After the transition, it began gliding nicely in a right hand pattern. Then, as it circled, it just went into a shallow spiral dive to the right, similiar to many gliders in a big thermal or turbulent air. [It was windy and gusty.] This progressed to the impact point. If I had tied the center section together like I did the outer wing panels[fiberglass cloth], I would most likely had no damage at all. I did suspend ops when I tore the stab off during a launch. Tore it off again after the glue dried and put it in the truck. I feel pretty good about how the launch went. All the other stuff will be fairly easy to fix.
I forgot to mention that I had modified the Sting with a “V” tail fin and a sub fin. The big rudder is gone. I also took out all the incidence I built into the wing mount.
“Then, as it circled, it just went into a shallow spiral dive to the right, “
Still, this seems to indicate a large fin? Not that I’ve spent a lot of time playing with DLG’s but I find the problem of the fin for stability in launch being too big for the glide. I had aCat I plane that would SAL fine untill I got the transition down, then all it would do is do a kind of Lomcovek when SAL’ed. It still flew fine when javelin tossed.
Your plane has a glide turn to the right, are you launching with your left hand or does it work out better flying right/right like a Cat I IHLG?
My second DLG is on the bench right now.
No, it’s not the fin in this case. I fly a lot of OT HLG which generally have huge fins. They aren’t usually a problem unless it is extremly bouncy and gusty. This fin isn’t anywhere near that relative size. What I have here is a slightly misaligned left wing panel. It seems to have 1/64 or so more incidence than the right panel. Possibly the panels shifted when they were glued. I am not sure. I weighted all down as per usual. The launch is generally straight ahead. I may see if I can make it glide to the left after the transition. First I will try the usual medicine on the right wing to see if I can cure the sickness. I have to work for the next five days so I can’t get back out there and try the thing again. I am hot to give this a try in better conditions.
Hi Dohrmc
For what it is worth, if you are right handed, retain the right hand glide don’t go left/left. Why do I say this? well at the recent OZ free flight champs I had the opportunity to try the new Surtees DLG prototype and the initial launch pattern for an inexperience right hander is to screw it into the ground, to the left. Len, like me, is a right hander and with practice can throw straight ahead into a climbing right glide. I did note that the fin area is quite small (like a standard outdoor HLG) and utilized a Vee stab and given a span of about 30″, the fin and stab areas would be more at home on an indoor ship, yes they are small. Also noted was the increased amount of dihedral used, almost like cow horns and this gives more side area to resist spiralling in. Hope this is helpful.
The 30″ Sting kit has been scrapped and will no longer be sold.
Ployd
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