Fuse

[Alan Gorham_]

David, the term you need to search for is RDT for Radio DeThermaliser. Can I also suggest you seek out and buy this months Aeromodeller magazine as it contains articles on both building vintage gliders and fitting them with modern RDT systems and a review of the "new" version of the KeilKraft Invader glider kit.

Also, if you want to mingle with modellers who are less R/C oriented and more FF, then I can recommend the Hip Pocket forum which is very active and will give you more hands-on advice for the type of models you have talked about.

**LINK**

[david miles 7]

I had another try this morning ( dog walking ) to find out the max range of my car key fob - it looks like 450 to 500 feet - not quite as good as 2 plus miles of competition grade radio D/T setups. Still, it all depends on the transmitter power. One could always beef up the transmitter power I suppose. Although I am now concentrating on thinking about starting to build a Tri-star glider, I have though, ( because I couldn't help myself! ) and because radio D/T setups look like they cost £100 plus, just bought on ebay, a Chinese transmitter receiver module ( two pcb's ) for 99p free postage!. I shall think about radio de-thermaslisers if I manage to get a F/F model in the air successfully!

David.

[J D 8]

Try the old trick of extending fob range by holding it to your head as you press the button.

[david miles 7]

JDM, when I read your post, I assumed it was the 1st April!. How can holding the fob against your head make it transmit further? I have already got a few strange looks from car drivers whilst out walking my dog, waving my car key in the air at what must have looked like nothing. You want me to now stand on the pavement holding my car key fob against my head!!!?

David.

[Don Fry]

David, if you put your car in the air, you would find the range increased by a big margin. I would imagine 400 feet ground range would go up to a number in the ballpark of two miles. And if a RDT is a hundred quid, someone is having a larf.

[david miles 7]

Hello Don. Interesting what you said about range being different in the air/on the ground. About the £100 RDT, I only looked at one site/example. Can you tell me the average price on a RDT with a range of 2 miles plus?

I still can't work out the transmitter against your head thing - perhaps one is becoming an extra aerial!

David.

[Don Fry]

No idea, I am a radio control flyer, but a basic 2.4 MHz Eu compliant transmitter. and a 2.4 comparable receiver, servo and battery is nowhere near that. You make great play about this two mile thing. You are aware that is standard range for anything described as full range, nothing special. All my kit has that sort of range.

Also, think about it for a moment, you push that DT button when the aircraft is getting away from your sight, because it's vital you don't lose sight of it. Believe me, once you have lost it, you don't acquire it again. And that point is about 300 meters for the stuff you are talking about.

Look in HobbyKing, they do a series of sub 5 gram receivers, a miniature 1 s lipo, and a 1.7 gram servo. Airborne kit, IRO £10. Car type cheap transmitter, not much. Micron radio control do similar, easier web site.

But as I've said before, while you go that route, I fail to see why you don't just fly the thing, and put a second servo in it. But I am also not a great supporter of the reintroduction of rotary engines.

[david miles 7]

Hello Don. Thanks for your reply. £10 for a radio D/T sounds more reasonable to me. As I said in previously, I am a novice who basically knows very little about flying model aircraft- although, I have picked up quite a bit of knowledge from this forum - I now know what a fuse and a D/T are!

Can you expand on what you meant by your last paragraph?

But as I've said before, while you go that route, I fail to see why you don't just fly the thing, and put a second servo in it. But I am also not a great supporter of the reintroduction of rotary engines.

[J D 8]

Hi David, Yes I recon one's head acts as an extension to the signal. When I was in the Coastguard we had a Mitsibushi L200 rescue vehicle. One day on the while walking the coast path to a minor incident a fellow coastguard arrived at the truck and needed to get into the locked vehicle for his safety gear.

We were at least a quarter of a mile up the coast path but could still see the truck. I did not fancy going back so I tried it and open it did and lock again after! Cheers John.

[Don Fry]

Hi David, sorry, reverting to my normal state of grumpy sarcastic, and not warranted. To my mind, and I make no apology to, or have less respect to devotees to free flight, their time is passing, both in terms of progress, and actually passing away.

For the same effort, at no more cost, that free flight glider can be radio assisted. You don't have to fly it. But if it goes down wind, you can steer it upwind. If it goes too high, you can spiral it down. Radio controlled does not set alight to the ground like a fuse can. It does not easily get away, out of your control. (You are at fault if an accident occurs even in a free flight jobbie). You minimise flying too high.( you break the law if you do fly too high).

I don't want to crush dreams, but I don't see the point. I accept we can agree to differ. But I fly my toys, after training, in safety, in aviation law, and competence to control.

I am currently being burdened with legislation, aimed at cousins in aviation, but hitting me because there is no means to differentiate the two. I have not got too much sympathy to free spirits trying their dreams, as it can end up with me getting the end result of the publicity and legislation.

But I would seriously advise you also make contact with the free flight forums. At the end of the day I have some dim memories of doing it in simpler times. They know vastly more than me about that aspect of the hobby today.

[david miles 7]

Hippocket are unable to accept more members while they renovate their site. There are loads of discussions to browse. through though, using the search engine. Unfortunately I couldn't find an answer to my query, so I will ask all you guys.

If you were a novice (like me ) starting to scratch build a F/F glider with 30" long fuselage and 46" wingspan, would you buy 36" lengths of balsa wood and try to cut out strips of small x sections, or would you try to buy everything pre cut to size, or just buy a jumbo pack of assorted 18" lengths and have scarf joint everything longer than 18"?

Second question. I am going to scratch build a 46" W/S Tri-Star ( tried to paste a link to model plan, but it didn't work!)

on the "outerzone" Tri-star plan page, at the middle/top of lower plan, it shows a small sketch of drinking straw/10swg wire - WING JOINER. I assumed that the wing would be made in one piece for strength. I do not understand what it means/how it works. If anyone has an idea, or can remember the glider, I would be grateful if they could explain it to me. Thanks.

David.

[Plummet]

David,

At the top of the fuselage plan sheet there is the text "Single wing joiner of 10 swg wire in 4 1/2" long drinking straw wrapped in tissue.

Then on the wings part of the plan of the centre section it shows the drinking straw in position against the top spa. The rib section shows 6 ribs with a hole for the straw.

The drinking straw is not "structural" it just acts as a guide to make sure that the wire joiner goes into the correct position through the holes in the ribs.

The old drinking straws were made of waxed paper, and would be difficult to glue, so wraping them in tissue would make them gluable, while the straw would resist the glue, and stop the wire being glued in as well.

It suggests that you build the entire centre section in one piece so that it is nice and straight, and then carefully cut it in two halves (remembering not to knacker the scalpel blade by trying to cut the wire as well).

Does this make sense?

Nowadays a piece of carbon fibre tube might be a better bet.

Plummet

Edited By Plummet on 30/03/2019 18:28:59

[Don Fry]

David, if you go to Slec, Balsa cabin, Inwood models, they sell stripwood in all shapes. At 36 inches long, or longer. Don't try to join wood if you don't have to. An airframe gets a load of stresses on it, and you don't want stiff bits, or weak bits in the structure.

Orfer medium density wood until you get your bearings. Buy more than you need, you make mistakes.

Long term, you need a bandsaw, then you cut your own from sheet. Slec do a strip cutter which will cut the small sections you want with scalpel blades.

Plummet is right. These plans are old, and technology has evolved. I haven't seen an wax straw in a shop in many a long year.

Are their full kits available? It would make your quest easier.

[PatMc]

Posted by Plummet on 30/03/2019 18:27:44:

It suggests that you build the entire centre section in one piece so that it is nice and straight, and then carefully cut it in two halves (remembering not to knacker the scalpel blade by trying to cut the wire as well).

Does this make sense?

Nowadays a piece of carbon fibre tube might be a better bet.

The supplementary download to the plan is the presentation article. The building instructions mention that the wire should be left out during the build.
I agree that a carbon tube would be better, for that matter a matching carbon rod to replace the wire would also make sense. OTOH the wing is only 46" span, it could be made in one piece by omitting the straw & wire unless storing or transporting it is a problem.
The one I made was in one piece & didn't require any extra strengthening of the centre section.

[Don Fry]

I note, e Bay do a Caprice glider kit, £33, from Al's Hobbies. Lazer cut bits, a plan, instructions, what's not to like. Still not easy, but David, how hard do you want it to be.

[PatMc]

David, a few questions.
How do you intend launching the model ?
Will someone be helping you ?
Do you have access to a suitable site that's big enough for the launch method ?
Do you realise the model will only be suitable for flying in light winds [probably no more than 8 - 10 mph]?
Also do you realise how far the model could travel downwind from the launch point in light (say 5 - 8 mph) winds over quite moderate duration times ?

[Martin Dilly 1]

If you're going to use a 10 swg wing joiner I'd suggest running it into 10 swg ali. tubing. Flitehook certainly have that, or its metric equivalent, as well as balsa supplied with the right grain for the job, - quarter grain for ribs, straight for longerons and spars. No connection, other than as a satisfied customer,

I'd be a bit wary of using a carbon rod or tube as a joiner; it's certainly very stiff, but when it's over-stressed on an over-enthusiastic launch it won't bend as a wire will, but just snap. Competitive F1A gliders, as flown in international free-flight contests, are now taking well over 40G on launch; one flyer used a 5mm steel injector pin as a joiner. That turned out to be a bad move; injector pins are very hard, but as he found out, not of a material intended for bending, as his first serious launch snapped the joiner.

[PatMc]

Martin, have you had a look at the plan for the Tri-Star ?
If there was enough stress to flex the 4.5" length of 10 SWG wire the 3/16" sq spar that the tube is bound to would have already snapped.

This model is designed for fairly gentle launches, one of the reasons for the questions in my previous post.

[david miles 7]

Thanks to Plummet, Don, PatMc and Martin, for answering my questions and pointing me to suppliers etc. You guys are a lot nicer that the ones on electronic forums!

I will answer your questions as best I can, so that you can tell me if I am wrong!

A) I am thinking of building wing in one piece, as I feel sure it would be stronger without a join and it will still fit in the boot of my car.

B) First model flight ever with grown up son ( apart from launching home made hot air balloon with burner basket and home made boomerangs out over the road and back into our back garden twenty years ago! ) I just want to have an enjoyable/exciting experience

C) site is top of gradient up a dirt track between arable fields height - don't know, possibly 100feet. Not bothered about farmers I did get to know one years ago that I liked a lot ( he lent me his JCB ) sadly he died of a heart attack aged 40 something. The rest I seem to dislike - for a good reason - I might just tell sometime!

D) 8-10mph wind? How will I be able to gauge that?

E) I am hoping that auto-rudder and fused D/T will keep it under control until I get confident Yes/No ?

I wonder how many blunders I have made with my assumption?

David.

[Don Fry]

A . Good idea, why complicate anything. But, a failure is catastrophic. Learn the difference.

B. Not applicable, not my dream.

C. You don't seem to have permission to fly. Apart from the aviation laws, look at old fashioned trespass. The slope bit raises a couple of queries. Are you aware of slope soaring, and wind shear, and its problems, and joys.

D. I don't know. It's a ( reasonable number ), that PatMc assumed you would know. It's a reasonable number I would view as ideal for my heavier machines. But top wind for your dream. You need a weather guru to tell you, or possibly you buy a wind measuring machine. Before you ask, I don't know a source of measuring machines. I know, having been trained.

E. No, the skills to get free flight machines to auto do what you want is a black art. I don't know how to do it. Neither do you. And I tell you straight, you need to get to a practitioner before (his/her) death. Not a skill to describe, I am sure. And you mention control. Free flight, means free flight. No control, it's a machine trimmed by a master, who has a fair idea how far to venture, so it's not broken very quickly.

You need to hook up with someone who can do what you dream of doing. If you want to do your dream alone, I reckon you will fail, quickly.

[david miles 7]

Thank you Don for your thoughts. Now it is time for me to concentrate on building it as well as I possibly can, and have some fun with my oldest son when I am able to see him, trying to get it to fly!

David.

[Martin Dilly 1]

E. No, the skills to get free flight machines to auto do what you want is a black art.

Not a black art at all. It's called trimming, and that doesn't mean what you do with the little knobs on your RC transmitter. If I can do it, then so can you, but it's certainly a good plan to get in touch with a club that specialises in free flight, so you can learn the principles of flight without damaging your model in the process.

Where do you fly, David? If you call the BMFA office they put you in touch with some help. 0116 2440028.