Hobby stuff

[Burgerman]

It doesent have to be big.

THIS is also a long range receiver. 30 miles or more.

24 channels. Full telemetry.

I generally add one as an extra 900. Just plug it into the already LoRa dual band 2.4 one.
So small it can go in a wing tip or fin.

10mm x 12...

[JohnnyUK]

The tech is fascinating and well above my level of competence, I couldn't figure it out electronics aren't my strong point. Seems you enjoy exploring and understanding the technology as much as using it in the field. You never crash??!! I rarely crash but never feel confident to fly it like I stole it, I never put enough hours into perfecting my flying technique or pushing the envelope. I'm a fair weather flyer who prefers analogue to digital, flying is a social event more than anything else. Why do you have to taunt the fragile geeks in clubs, can't you just be nice to them and applaud their crap planes/flying to make them feel good about themselves?

I'm fascinated by the capabilities of your FrSky system, thanks for explaining how they get round the international regs by offering various firmware standards to suit. Yes I guess the cops should be busy arresting real criminals, I've never known a modeller who's been asked to show his papers and doubt many law enforcers would have a clue how to do it. If you're happy to fly 'under the radar' so to speak then that's cool. The idea of having a £20k jet as a dot in the distance would terrify me, it's bad enough losing sight of a high level glider which is relatively slow. I get that pit in my stomach until I can find it in the sky and work out which way it's heading. You must have bloody good eyesight!

Why the bags of saline in your pulse jet wings? Can only assume it's ballast. Didn't realise it was only 4lb thrust on those CL pulse jets, presumably at 12-13lbs thrust they were much bigger? Did you fly the bigger jets and if so what did you put them in? Don't tell me you flew them at Beelsby

[Burgerman]

Where to start!

>>>Why do you have to taunt the fragile geeks in clubs, can't you just be nice to them and applaud their crap planes/flying to make them feel good about themselves?

The do it to themselves. They hate the fact that I turn up and fly loud super fast stuff, in what they consider "dangerous" (they are always safety nazis), usually cant fly anything safely at all, committe members, etc. They hate the fact that I actually can fly the wings off anything I turn up with and that I can build engines, and actually understand electronics, jet engines, etc at a high level. Mostly they shit themselves when you do a bunch of very fast close loud low passes with pylon racers, etc.

They spent most of their lives trying to make rules because of me and preventing me doing the stuff they are afraid of. And they are afraid of everything pretty much. When you turn up with oxygen bottles, nitrous bottles, purge systems, home made pulse jets, etc they all pack up and go home. Same happens when you fire up an open exhaust nitro burning ducted fan engine with a venturi instead of a carb, so it doesent throttle. When you have a rossi 65 fan motor running with no throttle in the pit area at 30,000 rpm or more with a prop on a tiny flying wing they do the same and evacuate!

They all think everyone should fly higher, a long way away, and be scale, or slow, and innofensive. To me that was boring. When I say I dont crash, I mean I genuinely dont if the thing I am flying is actually fliable! I have had wing flutter, lost elevators, radio failure, etc over my 55 years of flying. And in the first 10 years I crashed periodically. Its how you learn what not to do. But it becomes so intuitive that I dont think I have ever crashed due to thumb trouble since that point. That also annoys them.

I was banned from several clubs for basically flying loud fast stuff low... And the wrong way up. I once was "reported" to the committee because I launched a low wing high reving pylon racer inverted. Because no fusalage to hold the right way up! To me that was everyday obvious stuff. They considered that dangerous... They are frankly idiots.

The normals in society, and the low inteligence level ones seem to be atrracted to this hobby. Especially to the committee and making lots of "rules". Yet they cant fly. And they hate someone that can do what they cant with obvious ease. I did not insult or demean them other than run rings around them. It was the opposite way around. Normals do what they do. Anything thats different and they dont understand it or like it.

Two 1 litre bags in the wings is FUEL. Kerosene, with a little propylene oxide, 2 litres gives 3.5 minutes. Pulse jets eat fuel. And a single air bubble stops them dead. Theres no "flywheel" so they need to never ever misfire. So you fill the bags, remove ALL the air. Feed it under pressure with a pump to a fine jet internally. Pump RPM determines mixture. In my case it did this in flight. As you dive the engine breathes more air, so a pitot tube feeds the top of a 3 port regulator, that increases fuel pressure to match. I "trim" the mixture by pump RPM change via a rotary knob... They dont throttle as such. Well you can reduce thrust a little, by running leaner. But it burns the reed valves.

I havent flown a jet since 97. I flew from various places. Inc donna nook, elvington, waltham airfield, etc. Inc peaks.

Pulse jets bigger, yes much bigger than nationals on control line. Those are all small. Dont run properly! Bigger ones are lower frequency. But louder.

[Burgerman]

This isnt fast. Its a flying test bed for Pulse and turbines. Built big so it was smooth, slow, etc. Its also got 2 litres of fuel bags. But its all that I have left from the olde pulse jet era... Its been on my ceiling out of the way since 97... Accident.

I gave up on pulse jets when I built (rebuilt) a "shreckling" and a "Camps" turbojet. And swapped the Solent for a "proper" hobby one. They are now only of historical interest.

Its an italian pulse jet, 12.5lb thrust, and the big slow delta is 9lb all up. So it climbs.

Heres what most do not understand about the difference between props and jets.

A 15cc boring glow engine may make 12lb thrust. Static. The airflow from the engine may be 130 mph.
As it moves forwards, that reduces proportionally. When it actually reaches 130mph its making no thrust at all. Zero.

A jet makes 12lb thrust.
At 130mph it STILL makes the full 12lb of thrust...
At 500mph it also still makes 12lb of thrust.

But its actually better. As speed increases the engine gets more air. And so if you add more fuel to match you then get 14 or 16lb of thrust. So instead of thrust decreasing with speed, it increases. So the faster it goes the faster it wants to go!

So a low thrust jet aircraft is a LOT faster than an ever decreasing prop plane. Because of this, a small decrease in drag, gives a huge increase in speed.

This is why jets need long runways but are faster...

The airframe is a plus 25% KB-70 from the 1980s... A dutch design.
The motor is the same.
This is one below, but its running a little badly (rich) and way too heavy...


youtu.be/CxYuffN0qCY



A pic of my room...

[Burgerman]

Have a read here!
https://www.airtoi.com/pulse.htm#amtpulse

That page is 30 years old!!!

[JohnnyUK]

I can understand your frustration with clubs but you have to see it from their point of view too. It's mostly a social thing with an average member age of around 75, they're 'out to grass' and just want a bit of peace and practice flying a bit of foam in circuits just above stall speed. The younger members generally want something more exciting like 3D trick machines and fast EDF's, turbines and jets are banned from most clubs because of the safety implications. Whilst secretary of LADMAC I lobbied for more exciting things like competitions, combat, F5B stuff, turbines, fast wings and hotliners, the idea was for everyone to have a go, to play nicely and take it in turns ... the rest of the committee weren't interested so I went to GADMAC who were a little bit more outgoing.

I wouldn't want to be in a club where there's several members with big heli's and EDF's that all want their generator running flat out all day, it's not a peaceful day conducive to socialising. Fixed wing and helis don't mix well it usually ends in two factions who hate each other, always fighting for bigger share of the flying time. Clubs are like kindergartens for old folk.

That pulse jet stuff is fascinating I loved the video, it's such raw primitive power, simple and very effective. Are there manufacturers of 'stock' reed valves or do you have to stamp them out yourself? Are there any other wear parts? Sorry I read your description as 'bags full of saline' can see what you mean now, what a great way to get a custom shaped tank(s) with no air voids, didn't realise those bags were fuel proof too.

The airframe is a plus 25% KB-70 from the 1980s... A dutch design.

... is that the model hanging from your ceiling? Photo of bedroom looks good I'd be proud to have that hanging over my head.

Peaks would be good do people still fly there? Have you ever managed to fly through the railway bridge while stood on top of it? Never heard of anyone going from Donna Nook but that would be good with that FPV ZHOD, you could worry he seals for fun. Waltham looks perfect now but I never see anyone flying there, just the occasional dog walker and a lovely strip of fresh tarmac with nothing on it.

Good point about prop thrust being proportional to airspeed whereas the thrust continues with a jet, drag will determine the maximum speed.

[Burgerman]

Where to start...

turbines and jets are banned from most clubs because of the safety implications.

But...
The most dangrous are those that cant fly, or see, are about 50 to 80 and fly underpowered overweight "scale" toys. They are dangerous land in baby prams (seen it happen!) hit each other, and cars... And lose planes in fields, or go home with them in a bag.

Yet those are the ones that think I am dangerous! Non of them ever saw me crash, land long/short, miss the runway, ever. Having flown every single day of my life in the early years, in competition, with fast stuff and race stuff and have excellent accurate flying skills, better understanding, and better preparation. And I am dangerous because I fly all the stuff they are scared of? And I literally never crashed sometimes many years at a time. If I did it was trying daft tricks on disposable models. Like flying through the tunnel. And yes I tried that and no problem with a trainer. Tried again with an OPS powered pylon racer and not so good!

I taught many to fly. I discovered that some just get it. Have the skills, the intelligence, the eyesight, the judgement and can think fast. Some never will or can. Thats most. Do you know who tought me to fly, at about 10? 2 channel fleet radio. Me. I studied and watched gulls and followed through with my imaginary "sticks"... And imagined flying them. When supposed to be learning at school. I found that flying planes was exacly the same! Just as simple.

I think those that cant fly fast low, inverted, burst a balloon, etc 130mph plus planes confidently 6 inches high etc simply cant fly and shouldnt be allowed to do so alone. That ruled out 90% of the clubs... All the committee. As I say, 90% are not safe.

If an engine cuts and you crash then you CANNOT fly. If you cant land inverted, or catch a glider on landing in your hand, you cant fly. If you stall things and shout radio failure, or land "long" or short, or ever put a wrong stick in you cant fly!!!

Anyway thats me.

Reed valves?
I used to cut them out of spring steel sheet. 2 blocks of wood, and a fine band saw. And a drill, and clean sharp edges with fine wetdry. But then discovered micrometric techniches in lincoln. And they scanned one and cut out a load...
You can build them with 2 stroke reed valves too.

[JohnnyUK]

I agree with you it's the flyers who enjoy pushing the edges that can fly, the other 90% can't and will never fly it's just not in them. What we need is an exclusive club of members who want to fly like you do, problem is there aren't enough of them to make a viable club so they have to tag along with a 'normal' club. Clubs are essentially there to fulfil the needs of the majority, more of a social provision rather than encouraging members to do new aeromodelling things, if they don't have the numbers they're not viable. Do you get much grief if you rock up at Donna Nook or the Barratts with a plane? Where are the places to fly from where it's public but safe enough to fly with BMFA/CAA cover? What's the rules on flying from council land? I ask out of ignorance, we used to fly CL at Weelsby Woods but I've been going there every Sunday for the last 5 years and haven't seen/heard anyone. Can you still fly from Peaks?

The other thing that annoys me with most club members is the lack of appreciation for basic aerodynamic, electrical (esp soldering) and mechanical 'best practices' so the models are also unsafe. Clubs allow members to fly death traps on the basis someone can't afford a decent set up. They don't understand LIPO's so abuse them resulting in many lost models and many wasted £'s. Some members crash most flights they're that bad, the standard of repairs is usually appalling so it returns to the air even more unsafe than before. Of course when crashing they call "brown out", "total signal failure" or "dead spot" when I can see they've stalled it ... idiots

I used to feel more comfortable flying when I was young, I left the hobby for 40 years and haven't felt as confident this time around. If you're self taught then kept your hand in most of your life you should be good, what we rookies call a natural. I play guitar reasonably well but I'm not a natural, nothing comes easy and it never feels second nature, very mediocre skill level and flying's similar. I rarely crash and have had a few exciting models, my Acrowot 6S is fast and challenging for me no doubt you'd find it a breeze. One anxiety is the cost, I can't afford to stuff models regularly so that puts me off crashing. My biggest anxiety is eyesight, I do struggle to see things like my Mini Graphite which is fast and thin or the 8ft Heron at 1000ft ... hate that pit in the stomach when I lose orientation or not sure which way it's going even if it's only milliseconds. I've only had a few flights from a wheelchair and hated it, no doubt it's something else I need to get used to. I've said I'd go back to LADMAC this year and have a go so we'll see.

[Burgerman]

Agree with a lot of it. But:

My biggest anxiety is eyesight, I do struggle to see things like my Mini Graphite which is fast and thin or the 8ft Heron at 1000ft ... hate that pit in the stomach when I lose orientation or not sure which way it's going even if it's only milliseconds.

If you are watching a plane fly and occasionally interfering with it they you need to know its orientation. And need to see its shape and angle etc.

If you are actually flying a plane and have the stick time, then orientation isnt a thing that you ever think about. I have always had black planes, end to end since the Blues Brothers... Inc one with Blues Brothers sun glasses. Even the old test bed delta on my cieling is all black. Because I dont think about orientation.

Many people were amazed how far I fly away, ask how can you tell which way up they are or what its doing? Beyond some peoples vision entirely. When younger.
I dont NEED to see a plane to know its orientation instinctively as I have the sticks. I instantly have orientation if its ever lost the moment I move a stick because of the planes response. If its 1500 feet away on the horizon, 1000 foot up, almost dark, sun in eyes, just a dot in the sky, its just instant recognition as soon as it responds. IN MY HEAD.
So its never a thing that I ever think about. It simply doesent occur to me. You need to realise that 95% of the flight is in the pilots head - or should be. You know how it flies, recognise the responses, the shapes it makes etc. So just seeing a plane as a microscopic dot is plenty of information. How that dot responds is everything. And the faster they are the easier this is. Stop trying to see it, and just watch its movements and in your head you instantly know/recognise what its doing. Unless it turns into several dots. (yes, really!) then you are buggered.

Stop trying to "see" its orientation with your eyes, and relax. Let your brain recognise the response via its change of directions... The shapes it makes as you move the sticks. It becomes intuitive.

[JohnnyUK]

It'll be like riding a bike to you if you've had a lifetime of experience, you won't even give it a thought let alone raise your anxiety. It's like playing guitar, you have to gain sufficient experience not to think where you are placing fingers but to listen to the sound you are producing ... it takes most mortals years to achieve. It must be nice to fly a dot on the horizon without being concerned, I like to keep it close so I can see it clearly.

Stop trying to see it, and just watch its movements and in your head you instantly know/recognise what its doing

I'm sure that's good advice but it's down to me to stay calm and relaxed in order to do it, that's the problem bit

[Burgerman]

it takes most mortals years to achieve.

About 10 years old free flight stuff. Building. Etc. Till 65... So 55 years! Ony 35 of those flying several days a week. The last 20 just occasional. You dont forget how to ride a bike.

And if you need to think about the flying in any way, you are not in control. Should just happen, muscle memory, mental recognition of movement. If an engine cuts in a bad position I just react instantly, and have no plan. You subconsously assess its sped, position, if you can make te runway, wind, other options etc and initiate that in a fracton of a second. If you think, or need to, its too late. Like the comittee members that land in the pits or the next field...

Everything should be intuitive and muscle memory. Like you dont think about riding a bike of playing a guitar you just feel it, remember it. You cant plan.