|TJ Alexander||24/09/2018 11:40:13|
|103 forum posts|
OK, so I am Hi-curious, and bought a stake, surgical rubber, and the whole bit. There's lots of contradictory information on the net about proportions, so I wondered what the collective intelligence here suggested?
Secondly, I was wondering what might be a good (cheap/resilient) model to practice with. I don't want to spend many hours lovingly preparing a beautiful glider only for it to smash to bits before my eyes due to my inexperience. Is there a suitable high-start foamie?
My gliding fleet encompasses a Radian, a Conscendo, a Whipit, a Flyfly Fournier and (hopefully delivered today) a Superfly MiniDart DLG.
What the hell have I got myself into??!!
|john stones 1||24/09/2018 14:50:46|
10383 forum posts
Fair bit of strain on the bungie on launch T.J not familar with the models you quote, so couldn't say if suitable. In my limited experience, 100inch ish worked for me, even then it was mostly launch, do a few circuits then re launch, keeps you fit though.
|Old Geezer||24/09/2018 15:08:11|
|590 forum posts|
Get yourself a Gentle Lady, her name hints at the way she flies, but her airframe is much stronger than it looks and her manners on the bungee are exemplary. When properly trimmed the GL nearly flies herself up a bungee only needing interference at the very top with a little tap of down to release the tow-ring and prevent a stall on release. If you insist on a foamy, the Mpx EasyGlider Pro is easy to fly and very forgiving, and when properly trimmed will float on and on when landing. I can't stress enough that you will save yourself a lot of grief if you can find someone appropriately experienced in bungee launching to assist at the start, having said that, once you get the hang of it you can fly 'till your batteries are flat, without any other help. Finally - it is vitally important that both ends of your bungee are VERY securely fixed, particularly if using a spike or 'big corkscrew', the last thing you want is the spike pulling out of the ground and flying towards you at head height and warp speed! Also, put a securing peg in the ground at your launching point so you can stretch your bungee to there without the encumbrance of your plane and Tx, then when ready you can switch on, hook up, pick up Tx and listen to that lovely whoooosh as she goes up the line.
|Old Geezer||24/09/2018 15:08:51|
|590 forum posts|
Get yourself a Gentle Lady, her name hints at the way she flies, but her airframe is much stronger than it looks and her manners on the bungee are exemplary. When properly trimmed the GL nearly flies herself up a bungee only needing interference at the very top with a little tap of down to release the tow-ring and prevent a stall on release. Your Gentle Lady is brilliant drifting around in calm conditions, just flying her on the trims, but will also handle moderate winds, you just need a bit of down trim to penetrate up wind, and a little bit more still if she picks up enough lift that you bottle it and need to get back down to a comfortable height 😎.
If you insist on a foamy, the Mpx EasyGlider Pro is easy to fly and very forgiving, and when properly trimmed is quite floaty on landing ( it's nicer to just fly rudder/elevator when used purely as a glider - ailerons seem to lose more height in the turns ).
I can't stress enough that you will save yourself a lot of grief if you can find someone appropriately experienced in bungee launching to assist at the start, having said that, once you get the hang of it you can fly on your own 'till your batteries are flat, without any other help.
Finally - it is vitally important that both ends of your bungee are VERY securely fixed, particularly if using a spike or 'big corkscrew', the last thing you want is the spike pulling out of the ground and flying towards you at head height and warp speed! Also, put a securing peg in the ground at your launching point so you can stretch your bungee to there without the encumbrance of your plane and Tx, then when ready you can switch on, hook up, pick up your Tx, final check - and listen to that lovely whoooosh as she goes up the line.
Edited By Old Geezer on 24/09/2018 15:10:47
Edited By Old Geezer on 24/09/2018 15:20:59
|TJ Alexander||24/09/2018 16:58:05|
|103 forum posts|
Thanks. Good advice there.
|Frank Skilbeck||24/09/2018 18:39:22|
4383 forum posts
Multiplex Easy Glider Hi Starts very easy, I forgot to switch on the Rx once, it went up on the line, came off, circled round several times and landed in the next field (lucky it didn't catch a thermal!).
Dynaflight Bird or Time also bungees very easy.
Note on the tow you must use rudder for steering not ailerons.
It's great fun BTW and when you do catch a thermal it's all the more satisfying that you haven't cheated by having a fan on the front
|Mike Bell||24/09/2018 18:47:40|
237 forum posts
Great Planes Fling 2m is cheap and cheerful. Goes well off the bungee, been using mine for an annual club comp for years now and no wing clapping so far.
|Tom Sharp 2||24/09/2018 19:09:14|
3391 forum posts
Only problem is position of the towhook relative to the C of G,
Too far forward and it will hang in the wind like a wet kite.
Too far back and it will weave uncontrollably and end up diving into the ground.
|TJ Alexander||24/09/2018 22:41:11|
|103 forum posts|
Bird of Time is a plane I want to build one day, but I don't think I'll go for it as a starter. Fling looks like a contender. Easyglider looks good, but it looks like it may have been discontinued, and recent ones are pricy, so I can wait for a bargain on eBay or selling sites, I guess.
4145 forum posts
The book Radio Control Thermal Soaring by george Stringwell is a good source of practical info on thermal gliders in general. Although first published in 1981 much of it is still relevent today.
|paul devereux||24/09/2018 23:40:25|
|47 forum posts|
Can you already fly RC?
If you can't,learn on the Radian, it is a lovely plane for a beginner.
Once you have learnt to fly it is all easy, if you don't learn to fly, it is all impossible.
|paul devereux||24/09/2018 23:44:09|
|47 forum posts|
It is like riding a bicycle, your thumbs need to be ready and trained all the time ( and Mode 2 in the UK), once they are, you can fly RC!
|TJ Alexander||25/09/2018 11:28:52|
|103 forum posts|
I do fly RC, though I am still somewhat of a novice. And gliders are my passion.
I have several old books on RC gliding, and Stringwell rang a bell. I have his 'A Complete Guide To Radio Control Gliders' (1997), but that's one I haven't read yet (amazing how little time one has for books when one has a hyperactive five year old :D ). I assume this volume has a reiteration of the info in the soaring book you cite.
I will get stuck in shortly. Thanks for the tip.
|2502 forum posts|
Just a few points. Don't forget that a bungee system is quite different in its characteristics to a catapult launch, something that beginners forget and get themselves into all sorts of trouble over. A small and light model tends to be catapulted into the air if a very soft and progressive bungee is not used - sometimes squirreling about all over the place especially if the tow hook is a tad too far back and there is always a risk that the airframe will be overstressed, either with an instant wing break or a couple of seconds of fluttering and then failure.
Surgical rubber bungees do differ in quality and resilience, and years ago, we began to have trouble getting the right sort and it was very expensive when you did track some down. I don't know what's available now, but do beware of any rubber that doesn't easily stretch to say three times its rested length i.e you should be able to easily pull a one foot portion to say three feet or slightly under, without doing yourself a mischief. With practice and in the right conditions with the right model and bungee, very high launches can be made by kiting the model so as to stretch the bungee again and store more energy in it from the wind. I had my first successful R/C flights with 72" and 2M wingspan gliders over forty years ago from flat fields and counterintuitively found that larger models (100" +) always were much easier to launch and were far more stable on the line than smaller types - certainly until more experience was gained.
I used to love placing a model in the air and with care, having the bungee stretch again so the model was briefly behind my launch position and storing even more energy in the rubber - feed in a bit of 'up' and have the nylon scream as the tension came on. Great fun, but now usually supplanted by electric bungees either in the model or on the ground these days . Oh, BTW, dogs love to chew surgical tube.
George Stringwell's book (that I've had since the year dot) available here https://www.abebooks.co.uk/book-search/title/radio-control-thermal-soaring/author/george-stringwell/
Good luck, I hope it goes well.
Edited By Cuban8 on 25/09/2018 13:33:18
|Piers Bowlan||25/09/2018 19:31:47|
1771 forum posts
TJ good luck with your high start bungee, lots of good advice here. The Easy Glider has been mentioned by a couple of people, I just wondered why you prefer to use a bungee to launch your gliders to altitude rather than an electric motor and LiPo, perhaps you are a purist? eGliders just seem less hassle to me compared with setting up a bungee, although I have used them decades ago. Most gliders need plenty of lead in the nose to get them to balance so why not use a motor and battery to provide the weight instead? Useful weight instead of dead weight?
4145 forum posts
TJ, I assume that the book you have includes details of bungee launching so I haven't scanned the section from my older book.
I agree with Piers that E power is more practical & much less hassle than bungee launching. Also bungee launching doesn't mix well with other model flying at most club sites, it requires a lot of space & the line can cause problems with other flyers (and general public) the whole time it's in use from laying it out to reeling it back in.
Since I gave up any comp flying & as electric became so much more practical I gave up on any kind of tow launched gliders & now fly either Egliders or slope soarers. I still have a couple of old thermal soarers but only fly them from the slope.
PS Egliders don't need to have wings with the same over-engineered spars as gliders built to withstand tow launches but can get up to thermal altitude just as quickly. They're also more flexible in that if signs of lift are spotted they can be launched at shorter notice & more easily directed towards the desired area during the launch phase.
Edited By PatMc on 27/09/2018 21:44:15
|robert chamberlain||10/10/2018 01:21:24|
|114 forum posts|
My home made bungee launch consists of 100 feet off surgical 3/8 o.d. tubing and 400 feet of good kite string. It has been several years since I used it but as I remember I walked back 80 steps for the launch. I am pretty sure of this 80 step idea but it could be a senior moment ! With this I would launch my Bird of Time with the line going straight up and the BOT sliding off easily.
|SR 71||10/10/2018 09:49:24|
271 forum posts
Im just building a 4M scale glider and wondered about putting a motor in the front, but then its not scale, then thought about bungee, but seems a lot of messing to get it up, also wing clapping, in the end im going for a tow up behind my 50cc Great Planes Revolver, should be interesting as iv never done it before
|John Duncker||10/10/2018 21:11:59|
|79 forum posts|
Oooh this thread brings back memories of summer evenings spent in a school playing field surrounded by factories and car parks. I had a fairly wussy bungee but it was enough to get my Flair Sunrise high enough that I could go sniffing for lift off the car parks and factory roofs. 30 minute flights were common place.
I learned a lot about milking the most from weak lift and how to fly as efficiently as possible.
|Barry W||10/10/2018 23:56:13|
76 forum posts
There is a lot of good advice in the above replies.I have done quite a bit of bungee launching with a Goldberg Gentle Lady which is an excellent glider. I believe that Sussex Models still sells the kit. I would just like to add a couple of point. On the glider end near the tow hook ring place a small red flag. The flag adds a bit of drag to the line and helps it to unhook from the glider at the top of the launch. Also it help find the end of the line when you are looking for it after the launch. Most of my bungee launches were from nicely mown school fields when I lived in California. When I tried bungee bungee launches from a model aircraft field in the south of France it was a real problem due to the tough weeds that were mixed in with the grass and made it difficult to run out the bungee line without getting tangled up with the weeds. I ended up abandoning the bungee and fitted an electric motor and the GL is still flying to this day now that I am back in the US.
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