Richard Clark 2
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Posts posted by Richard Clark 2
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Posted by Jon - Laser Engines on 03/07/2020 16:41:15:
Richard, to clarify my comments my Hurricane feels like its stood on top of a ball. Start to roll, wings go over a bit, Ok, over a bit more..and then it falls off the ball and flips over. That is not how its supposed to be and some dihedral would help it out.
As for the Hurricane being better to aerobat than the spitfire..depends on the metric you use. I can imagine the Hurricane being much better at tight aerobatics at low speed/altitude. Equally, a spitfire (especially a late Mk) would mug it if you wanted to do a larger 'pattern' routine due to its greater power and better overall aerodynamics.
If i ever win the lottery i will buy one of each and test it
In the early 1970's a Spitfire Mk 9 with a low hours engine, a spare zero hours engine still in its crate, , a spare zero hours prop and a three year Certificate of Airworthiness was advertised for 5000 quid in Flight magazine. How times have changed
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Posted by Tosh McCaber on 03/07/2020 17:15:23:
Hmm, thanks Geoff, but, having used tape, and sticking motor, and associated ESC etc where they're going to be, the position that I've shown the battery is where it all balances out!
That being the case, my original thoughts for a top hatch would leve the battery 'way down and inaccesible!
Just put a hatch slightly larger than the battery on the underside of the fuselage. Simples.
I leave it as an exercise for you to figure out how to make a strong yet quick release hatch catch so the hatch retains the battery should it attempt to escape during a high G manoeuvre
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Posted by Peter Jenkins on 03/07/2020 18:27:46:
Do you mean something like Oratrim? Just cut to the desired shape, put into a bowl of water with a few drops of detergent and peel off the backing strip. Slide the trim into place and squeegee out the water. Done.
Make sure it's in exactly the right place before squeegeeing out the water though. You won't get it off again.
I dunno what backing Oratrim use but Solartrim used thickish white paper. If you wet it first you could never get the backing off without lots of it tearing so you couldn't get it all off.
So I always thoroughly wet the surface it is going on.. Also that allows you to slide it about easily before you squeegee it.
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Chris and Bob,
Often the part that goes through the fuselage isn't constrained in an outer tube. My 90mm 55 inch span EDF 10 cell approx 4 Kilowatt Black Horse Viperjet weighs nearly 5 Kg (their claimed weight didn't originally include the batteries) and the way the wings flexed just holding it up by the tips I would never have trusted the carbon joining tube in flight, least of all with a high G manoeuvre. So I found a close fitting carbon rod and epoxied it into the provided tube.
The better fly fishing rod manufacturers go to great lengths to produce what they call a high 'hoop strength' in their rods.
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Posted by perttime on 03/07/2020 14:39:35:
Posted by Chris Walby on 03/07/2020 12:46:43:
...
I have a cunning plan, ..
Gotta love cunning plans
Being cheap, I would have stuck with the dowel and sandpaper plans.
Whether carbon and epoxy particles are carsinogenous, or not, they are pretty nasty just mechanically. Better keep them away from your insides. I prefer to keep them from embedding themselves in my skin too.
While a tube, carbon, brass, light alloy, or glass, is fine in the wings you should use a solid rod as the wing joiner. A tube joiner will flatten into an elliptical shape under strain which weakens it in the vertical plane. Thus weakened it flattens even more, weakens further, and eventually breaks.
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Posted by Jon - Laser Engines on 03/07/2020 09:19:19:
In general the more dihedral you have, the more stable the model is in roll. Its more complicated than that, but that is all we really need to know.
The pendulum effect is real, but aerodynamic forces will over power it. Most high performance aerobatic aircraft are mid wing and while there are other reasons that is a good thing its probably a contributory factor. Very few high wing aircraft have large dihedral angles and yet most low wing aircraft have a reasonable amount. High wing aircraft with anhedral are trying to make the aircraft less stable longitudinally for some reason. Often this is to stop dutch roll in high wing T tail aircraft. BAe 146's and most military transports are high wing T tail aircraft with swept wings and these all have anhedral to prevent dutch roll and other stability problems.
To say that dihedral angle means nothing if you have ailerons is flat out wrong. I took all the dihedral out of my little hurricane to make it more scale and the effect is clear. The wings do sometimes look droopy, and while stable wings level, it falls into turns more than my old one did with a few degrees on it. Admittedly this is partly due to other scale inaccuracies in the wing meaning the model does not behave like the full size, but compared to the same model with a dihedral wing there is a clear change in the handling.
In terms of the OP if you have a 1.5'' target at the tip +/- 1/4 inch will make very little difference and in truth +/- half inch would probably be ok. You would notice it, but only if you flew the two back to back. I would not be thinking of taking it all out but i would also not be loosing sleep about getting it totally accurate.
Jon,
I am afraid I have to disagree. While dihedral gives a change in the handling (mostly making aerobatics more difficult - a Hurricane is MEANT to fall into turns easily and is often reported to be more aerobatic than a Spitfire) its presence or absence simply does not matter.
Most modern light aircraft, both low and high wing, have little or no dihedral - the Piper Cherokee is somewhat of an anomaly today.
As for models, I mostly fly 'classic pattern' ones, plus a few 'Auster' type planes. But the only model I have where the rudder, though large with a lot of movement, has zero effect on the overall flight path when used alone is the very semi-scale Graupner Bolkow 'Monsun'.
Dihedral on a parasol model? I wouldn't bother. It makes a Luton Minor look weird, but it does make a early Pfalz look cute.
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Our flying site is in England and is managed, though not owned. by a state organisation, one of the most environmentally damaging organisations in the entire UK.
It has lost interest in the coronavirus but has suddenly developed a great regard for 'rare' ground nesting birds, all of which are so UNrare that that they don't even warrant a conservation status, as they are merely locally uncommon, just like parakeets, humming birds, vultures, etc.
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Posted by Jason Channing on 03/07/2020 09:04:12:
lesson 1 = You don't have dihedral on an airliner just to keep the pods clear of the ground or just to get the look correct although it is funny. Book wise I have read Martin Simons book many times and is a particularly good read.
Pods? Take a look at the front view of an A380.
Also note that I deliberately confined my 'looks' comment to light aircraft as they are often 'consumer' products, whereas airline passengers often don't even get to see the outside of the airliner they are about to fly in.
As for 'looks' Cessna actually admitted that the swept fin of their light aircraft was introduced only for appearances' sake, while also admitting it is heavier and needed more area to be equally effective as the previous roughly rectangular one.
As it happens I have an HNC in aerodynamics/aircraft engineering, spent several years in the aircraft industry after the six year 'student apprenticeship' which led to my HNC, and am a 'full-size' pilot of everything from microlights to 'executive' jets.
A little exercise for you. Tell us (1) what happens when you use the rudder to induce a turn, (2) what happens when you use the ailerons to induce a turn, (3) what part does the fin play in a turn?
Edited By Richard Clark 2 on 03/07/2020 14:13:43
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As long as you have ailerons dihedral is completely unnecessary on an RC aircraft.
So what's it for?
Mostly to prevent a droopy appearance, as Tim says. (That applies to full-size 'light' aircraft too which today are mostly 'consumer products' not purchased entirely for logical reasons. Even then few modern light aircraft have any, except for any thickness taper being entirely on the underside, again for appearance.)
Another reason is to keep low set 'podded' jet engines as far off the ground as possible.
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Posted by Ian Whittaker on 01/07/2020 10:12:28:
Thanks for that Denis. I do haveBootcamp fitted (although I’m terrible on computers!). I have a Phoenix 4 DVD rom but can’t find the transmitter I used with it nor the lead since I’ve moved house twice in the last 12 months!
Im fancying the Real Flight one but can’t find much about how it performs with helicopters - does anybody use it rotary wing please?
Real Flight Basic is fine if you just want an RC simulator. It's got several helis including a training one, and also a Harrier which with practice isn't as impossible as it first appears.
The 'full' Real Flight is as much a computer game as it is a simulator, and so are some of the others.
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Posted by MattyB on 30/06/2020 15:54:16:
.........PS - Richard Clark 2 will no doubt be along in a moment to tell you that I am an OpenTX zealot and should never be trusted, but in this instance the fact that these radios run OpenTX is not the main factor; they are just the only new TXs available on the market that can speak to your existing Hitec RXs. If you are prepared to ditch those receivers you can go with any other brand and avoid OpenTX if you wish, but that will result in a lot more expense and swapping of RXs. You pays your money and all that...Edited By MattyB on 30/06/2020 16:23:43
Well, you ARE an OpenTx zealot
. However I think you CAN be trusted I could even be tempted to buy an OpenTx transmitter, provided it is made by somebody who might be around for some time, as FrSky is appearing to be. Not some of the others, who's existence is often nearly as short as a mayfly, thus no spares and no service if you need it in a year or so's time.
Though I consider many of the things you CAN do with OpenTx, if you are nerdy enough, to be totally pointless.
The problem with 2.4 is the variety of incompatible protocols, done purely in an 'Apple like' attempt by the major manufacturers to 'lock you in'. I don't think multi-protocol modules, with all the faffing around described in your link will be popular enough to solve this. .
What do I personally want in a radio?
Easy 'mechanical' mode change (unlike many Futaba and Spektrum radios).
Fully user assignable sliders, knobs, switches, buttons, etc. It wouldn't do any harm if the sticks were fully assignable too.
'Curves' on all channels, not just the two typical 'heli' ones. (You can even make UC door sequencers with these.)
The option to assign as many ailerons, elevators, or whatever as you want.
Mixers with multiple inputs.
As you know, both OpenTx and Multiplex can do all these things, simply because they are 'object orientated' rather than 'function orientated'. I suspect Jeti and the new Powerbox Tx are too, but I have never seen either.
What puts me off a radio?
The pointless 'bus' systems which merely over-complicate things (and are another attempt to lock you in). You may need marginally less wires but you need often pricy little boxes and, more importantly, access to them, which means extra hatches, mostly in the wings. And with Futaba, if you need more than 8 channels the only alternative is a near 200 quid 16 channel receiver.
Nutty prices, such as the new Powerbox Tx. I don't see that lasting long. Nor do I suspect will Multiplex. They alreadydropped thr 'new' Profi and all Evo's except one. As a result I have purchased my last Multiplex receiver - I have about 30 and will swap them from plane to plane as needed rather than buy more.
Edited By Richard Clark 2 on 01/07/2020 17:20:27
Edited By Richard Clark 2 on 01/07/2020 17:23:36
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When I was young in the 1960'a I shopped at 'Sports' of Totton (which then had a population of about 10,000) near Southampton. Sports sold almost everything model planes though it was a 'general' sports shop too. In addition there were two other Totton shops that had small model plane sections.
'Jetex' had their factory in Totton. Its owners also owned Frog, but that was somewhere else.
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17 miles each way to Spire Model near Salisbury.
Failing that I shop online with Sussex Model Centre. Occasionally I buy motors direct from Hacker in Germany.
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You've go to hand it to Microsoft.
Having noticed the Batwing I went to Vogel-Fly's website and used Microsoft translate from German to English.
Microsoft's translation of the song accompanying the Batwing video into English is absolutely amazing.
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Posted by Mike Etheridge 1 on 27/06/2020 11:02:58:
The thing I remember about the fuselage repair is that the horizontal tray that supports the fuel tank etc must be introduced prior to the fixing of both the fuselage sides. Could that relate to the gluing of the formers on one side first? I worked without instructions or jig as the plane I repaired was a ready made.
Edited By Mike Etheridge 1 on 27/06/2020 11:05:04
Edited By Mike Etheridge 1 on 27/06/2020 11:07:20
"Could that relate....."
No.
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Posted by Richard Clark 2 on 27/06/2020 05:55:34:Posted by Geoff S on 26/06/2020 15:33:03:Posted by Richard Clark 2 on 26/06/2020 15:03:01:
As an aircraft has no ground reference, provided you can take off and land approximately into wind, and your plane can make sufficient speed over the ground from any direction to get 'home' the windspeed doesn't matter..
An aircraft, once in the air has no 'awareness' of windspeed (which is referenced to the ground) so it is always flying in still air. It doesn't even know the air is going 'up' over a hill.
It's the same with downwind and upwind turns. Downwind or upwind of what, exactly? You, the cow over there, or that castle two miles away? The plane doesn't know you, or any of those things, exist.
That's perfectly true in a steady wind but usually the stronger the wind the more turbulence you get from any nearby obstructions (as well as weather system turbulence generated thermally or otherwise) and the model certainly notices that.
Before I was forced to give it up (and eventually took up modelling) I was a passionate dinghy sailor/racer and so wind strength and direction figured highly in my perceptions. We raced on reservoirs and gravel pits mostly and that was noticeably trickier than sailing on the sea which we only did rarely, usually for national championships. However, the same thing happens with current. If the whole racing area is experiencing the same current it doesn't matter so much but huge gains (and losses) can be made if you misjudge tidal or other effects.
Geoff
I basically I agree about turbulence but wind speed and turbulence are different things. Wind shear (another ground related effect) needs to be considered too, but overall I think wind shear is more relevant to full-size aircraft than models as full-size aircraft are often only 'one wingspan' above the ground when its effects are noticed..
Yachts are different. Sailing is more complicated than flying because currents and winds are each going at their own speeds and their own directions and both have to be taken into account, as do anchored buoys when you are racing. To a yachtsman nothing is stationary relative to him and all three are important at any given time..
Many model flyers bring problems for themselves. They use themselves as a totally non-existent (for the model) point on the equally non-existent ground and then use that invalid reference to attempt both to fly at a constant ground speed and to fly 'symmetrical' shapes relative the ground.
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Posted by Geoff S on 26/06/2020 15:33:03:Posted by Richard Clark 2 on 26/06/2020 15:03:01:
As an aircraft has no ground reference, provided you can take off and land approximately into wind, and your plane can make sufficient speed over the ground from any direction to get 'home' the windspeed doesn't matter..
An aircraft, once in the air has no 'awareness' of windspeed (which is referenced to the ground) so it is always flying in still air. It doesn't even know the air is going 'up' over a hill.
It's the same with downwind and upwind turns. Downwind or upwind of what, exactly? You, the cow over there, or that castle two miles away? The plane doesn't know you, or any of those things, exist.
That's perfectly true in a steady wind but usually the stronger the wind the more turbulence you get from any nearby obstructions (as well as weather system turbulence generated thermally or otherwise) and the model certainly notices that.
Before I was forced to give it up (and eventually took up modelling) I was a passionate dinghy sailor/racer and so wind strength and direction figured highly in my perceptions. We raced on reservoirs and gravel pits mostly and that was noticeably trickier than sailing on the sea which we only did rarely, usually for national championships. However, the same thing happens with current. If the whole racing area is experiencing the same current it doesn't matter so much but huge gains (and losses) can be made if you misjudge tidal or other effects.
Geoff
I basically I agree about turbulence but wind speed and turbulence are different things. Wind shear (another ground related effect) needs to be considered too, but overall I think wind shear is more relevant to full-size aircraft than models.
Yachts are different. Sailing is more complicated than flying because currents and winds are each going at their own speeds and their own directions and both have to be taken into account, as do anchored buoys when you are racing. To a yachtsman nothing is stationary relative to him and all three are important at any given time..
Many model flyers bring problems for themselves. They use themselves as a totally non-existent (for the model) point on the equally non-existent ground and then use that invalid reference to attempt both to fly at a constant ground speed and to fly 'symmetrical' shapes relative the ground.
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Posted by David Ashby - Moderator on 26/06/2020 19:51:34:
The fuselage jig is included with the kit.
But jig or no jig the instruction photos indicating all the formers are glued to one side first is still nuts.
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Don't let grown ups see you playing with it
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As an aircraft has no ground reference, provided you can take off and land approximately into wind, and your plane can make sufficient speed over the ground from any direction to get 'home' the windspeed doesn't matter..
An aircraft, once in the air has no 'awareness' of windspeed (which is referenced to the ground) so it is always flying in still air. It doesn't even know the air is going 'up' over a hill.
It's the same with downwind and upwind turns. Downwind or upwind of what, exactly? You, the cow over there, or that castle two miles away? The plane doesn't know you, or any of those things, exist.
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Posted by Gsky on 23/06/2020 15:29:03:
Thanks for the tip Jesus, I’ve heard there are a few mistakes/omissions in the instructions. I’ll try and have a good read of them and watch mojos videos while waiting for supplies.
Edited By Gsky on 23/06/2020 15:29:32
Yes. You should definitely take note of Jesus' comment and a few other things too, such as the poor instructions.
Basically the plane is designed as an ARTF and Seagull, for some weird reason known only to themselves, decided to not glue the parts together and sell some of them as kits.
But ARTFs are not designed as 'home build' kits The parts have been designed to be cut out by an infinitely patient computer so complicated shapes do not matter, and have a lot of 'keyed' parts so they can to be put together under initial close supervision until the totally disinterested person doing it has become sufficiently 'robotic' to do it by him or her self hundreds of times over with no thought whatsoever.
Written instructions were not required so are just an afterthought and the fuselage (and probably the wing too) will have been designed to be assembled on a jig to avoid banana shaped fuselages and warped wings. You don't have any of that jig stuff.
PS: The difficulty of flying a model Spitfire is much exaggerated. The problem for a beginner is they don't have a straight line anywhere so building it involves a lot of carving and trying to get balsawood to bend in two different ways at once, so it's all very time consuming. But you won't have any problem with the actual flying once you've flown the Challenger for a while.
Edited By Richard Clark 2 on 26/06/2020 07:09:15
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Posted by Steve J on 25/06/2020 15:01:51:Posted by Barrie Lever on 25/06/2020 14:51:01:
The BMFA sample constitution is a good starting point for a club or special interest group to form a constitution that is robust, however you are allowed to menu pick what is appropriate.
I understand. I was simply pointing out that the BMFA like to have their cake and eat it. They say different things in different documents.
I think you will find the constitution is aimed to also cover legal crap that happens within clubs, the BMFA get a couple of cases a week where someone feels agreeved at how their club is treating them and bitch to the BMFA about it.
I think that the BMFA should require certain standards of affiliated clubs when it comes to how they treat their members and clubs that do not meet these standards should be disaffiliated.
Steve,
"Disaffiliated"? You think the BMFA deliberately WANTS to lose members?
The BMFA has the common sense not to "require" anything - it's all just 'guidelines'. They know full well that if they tried to order their members about the membership would drop dramatically.
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Posted by David Hall 9 on 25/06/2020 11:22:26:
I have recently tried my first IC powered plane for more than 20yrs.
My Ballerina flies well on the OS FS40S, I am enjoying the change.
I am drawn to the retro style of the Ballerina and am now thinking of building an Astro Hog.
What four stroke motor would suit the 72" Astro Hog and, as I have an SC52FS engine, what span might that suit?
The designer's original Astro Hog (1958) used a K&B 35 two-stroke and he won lots of US aerobatic competitions with that engine.
Even an SC52FS will be more powerful than the original K&B though performance will be very 'mild' by modern standards.
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Posted by Steve J on 25/06/2020 12:51:05:Posted by Barrie Lever on 25/06/2020 12:32:50:
If you give small time politicians a little bit of power they abuse it, like you say the 'A' cert has never been intended as a license.
The BMFA say various things on the subject. On one hand they say that
"It is important to appreciate that the scheme is not primarily about permitting or licensing. Fundamentally, the scheme is all about personal goals and challenges. It is entirely voluntary and intended to provide every RC flyer with something to aspire to and aim for, should they so wish. The scheme is not compulsory and BMFA insurance is NOT conditional on holding any of the achievements !" (Achievement Scheme Handbook)
and on the other hand they also say that
"All flying members must attain the minimum standards of flying required under the club name training scheme before receiving the BMFA ‘A’ Certificate and before being permitted to fly indirectly supervised."
"Any pilot not holding their solo qualification for the type of aircraft they are flying must not fly without the supervision of an instructor or their specially appointed deputy if the instructors are absent from the field. "
(Example constitution)
Their left hand obviously doesn't know what their right hand is doing
Do you remember all their stuff about 'child protection'? They even suggested clubs appoint a 'child protection' officer'.
Totally overlooking that all that child and vulnerable people stuff ONLY applies if working with children and/or vulnerable people is your MAIN activity. If it isn't you don' have to do anything at all.
Receivers
in Spektrum/JR
Posted
Thanks for all those replies and it certainly makes sense. I couldn’t understand why a new discontinued receiver was being offered at such a reasonable price, obvious really when I read what you were all saying. I’ll follow your advice and get an AR620 from one of the better known suppliers.
Thanks again.
Ashley
If in ANY doubt at all just buy from a well-known Spektrum supplier, as you say.
In the UK, Also ideally with a 'brick and mortar' shop, or at a minimum, with both a real UK physical address and a real UK landline phone number shown on their web page (just phone it as a test and see what happens. If it's not answered, doesn't ring, or you are in any way suspicious just ring off).
Model planes are not an exercise in money saving. And unlike a TV or stereo they don't just stop if something ceases to work